diff --git a/eslint.config.mjs b/eslint.config.mjs
index 2356e845..354d8f37 100644
--- a/eslint.config.mjs
+++ b/eslint.config.mjs
@@ -34,6 +34,8 @@ export default [
   {
     files: ['**/*.js', '**/*.mjs'],
     rules: {
+      'one-var': ['error', 'never'],
+      curly: 'error',
       strict: 'error',
     },
   },
diff --git a/lib/parser.js b/lib/parser.js
index 508fb7c0..e8f50102 100644
--- a/lib/parser.js
+++ b/lib/parser.js
@@ -158,7 +158,7 @@ export const parseSvg = (data, from) => {
 
   sax.onopentag = (data) => {
     /** @type {XastElement} */
-    let element = {
+    const element = {
       type: 'element',
       name: data.name,
       attributes: {},
diff --git a/lib/style.js b/lib/style.js
index 0b76d00b..7d054970 100644
--- a/lib/style.js
+++ b/lib/style.js
@@ -1,7 +1,7 @@
 import * as csstree from 'css-tree';
 import * as csswhat from 'css-what';
 import { syntax } from 'csso';
-import { visit, matches } from './xast.js';
+import { matches, visit } from './xast.js';
 import {
   attrsGroups,
   inheritableAttrs,
diff --git a/lib/svgo-node.js b/lib/svgo-node.js
index efe67ab9..47a4c03a 100644
--- a/lib/svgo-node.js
+++ b/lib/svgo-node.js
@@ -3,12 +3,12 @@ import fs from 'fs/promises';
 import path from 'path';
 import {
   VERSION,
-  optimize as optimizeAgnostic,
+  _collections,
   builtinPlugins,
   mapNodesToParents,
+  optimize as optimizeAgnostic,
   querySelector,
   querySelectorAll,
-  _collections,
 } from './svgo.js';
 
 /**
diff --git a/lib/svgo-node.test.js b/lib/svgo-node.test.js
index fec13028..47fc7c79 100644
--- a/lib/svgo-node.test.js
+++ b/lib/svgo-node.test.js
@@ -1,6 +1,6 @@
 import os from 'os';
 import path from 'path';
-import { optimize, loadConfig } from './svgo-node.js';
+import { loadConfig, optimize } from './svgo-node.js';
 
 const describeLF = os.EOL === '\r\n' ? describe.skip : describe;
 const describeCRLF = os.EOL === '\r\n' ? describe : describe.skip;
diff --git a/lib/svgo/coa.js b/lib/svgo/coa.js
index 1aad945e..2b36c8d3 100644
--- a/lib/svgo/coa.js
+++ b/lib/svgo/coa.js
@@ -2,7 +2,7 @@ import fs from 'fs';
 import path from 'path';
 import colors from 'picocolors';
 import { fileURLToPath } from 'url';
-import { encodeSVGDatauri, decodeSVGDatauri } from './tools.js';
+import { decodeSVGDatauri, encodeSVGDatauri } from './tools.js';
 import { loadConfig, optimize } from '../svgo-node.js';
 import { builtin } from '../builtin.js';
 import { SvgoParserError } from '../parser.js';
@@ -151,7 +151,7 @@ async function action(args, opts, command) {
 
   if (process?.versions?.node && PKG.engines.node) {
     // @ts-expect-error We control this and ensure it is never null.
-    var nodeVersion = String(PKG.engines.node).match(/\d*(\.\d+)*/)[0];
+    const nodeVersion = String(PKG.engines.node).match(/\d*(\.\d+)*/)[0];
     if (parseFloat(process.versions.node) < parseFloat(nodeVersion)) {
       throw Error(
         `${PKG.name} requires Node.js version ${nodeVersion} or higher.`,
@@ -224,7 +224,7 @@ async function action(args, opts, command) {
     if (input.length && input[0] != '-') {
       if (output.length == 1 && checkIsDir(output[0])) {
         const dir = output[0];
-        for (var i = 0; i < input.length; i++) {
+        for (let i = 0; i < input.length; i++) {
           output[i] = checkIsDir(input[i])
             ? input[i]
             : path.resolve(dir, path.basename(input[i]));
@@ -245,7 +245,7 @@ async function action(args, opts, command) {
 
   // --folder
   if (opts.folder) {
-    var outputFolder = (output && output[0]) || opts.folder;
+    const outputFolder = (output && output[0]) || opts.folder;
     await optimizeFolder(config, opts.folder, outputFolder);
   }
 
@@ -254,8 +254,8 @@ async function action(args, opts, command) {
     // STDIN
     if (input[0] === '-') {
       return new Promise((resolve, reject) => {
-        var data = '',
-          file = output[0];
+        let data = '';
+        const file = output[0];
 
         process.stdin
           .on('data', (chunk) => (data += chunk))
@@ -274,7 +274,7 @@ async function action(args, opts, command) {
 
     // --string
   } else if (opts.string) {
-    var data = decodeSVGDatauri(opts.string);
+    const data = decodeSVGDatauri(opts.string);
 
     return processSVGData(config, null, data, output[0]);
   }
@@ -308,7 +308,7 @@ function optimizeFolder(config, dir, output) {
  */
 function processDirectory(config, dir, files, output) {
   // take only *.svg files, recursively if necessary
-  var svgFilesDescriptions = getFilesDescriptions(config, dir, files, output);
+  const svgFilesDescriptions = getFilesDescriptions(config, dir, files, output);
 
   return svgFilesDescriptions.length
     ? Promise.all(
@@ -396,8 +396,8 @@ function optimizeFile(config, file, output) {
  * @return {Promise<any>}
  */
 function processSVGData(config, info, data, output, input = undefined) {
-  var startTime = Date.now(),
-    prevFileSize = Buffer.byteLength(data, 'utf8');
+  const startTime = Date.now();
+  const prevFileSize = Buffer.byteLength(data, 'utf8');
 
   let result;
   try {
@@ -413,8 +413,8 @@ function processSVGData(config, info, data, output, input = undefined) {
   if (config.datauri) {
     result.data = encodeSVGDatauri(result.data, config.datauri);
   }
-  var resultFileSize = Buffer.byteLength(result.data, 'utf8'),
-    processingTime = Date.now() - startTime;
+  const resultFileSize = Buffer.byteLength(result.data, 'utf8');
+  const processingTime = Date.now() - startTime;
 
   return writeOutput(input, output, result.data).then(
     function () {
diff --git a/lib/svgo/tools.js b/lib/svgo/tools.js
index cbd6aa6e..abdf848b 100644
--- a/lib/svgo/tools.js
+++ b/lib/svgo/tools.js
@@ -23,7 +23,7 @@ const regReferencesBegin = /(\w+)\.[a-zA-Z]/;
  * @returns {string}
  */
 export const encodeSVGDatauri = (str, type) => {
-  var prefix = 'data:image/svg+xml';
+  let prefix = 'data:image/svg+xml';
   if (!type || type === 'base64') {
     // base64
     prefix += ';base64,';
@@ -45,13 +45,15 @@ export const encodeSVGDatauri = (str, type) => {
  * @returns {string}
  */
 export const decodeSVGDatauri = (str) => {
-  var regexp = /data:image\/svg\+xml(;charset=[^;,]*)?(;base64)?,(.*)/;
-  var match = regexp.exec(str);
+  const regexp = /data:image\/svg\+xml(;charset=[^;,]*)?(;base64)?,(.*)/;
+  const match = regexp.exec(str);
 
   // plain string
-  if (!match) return str;
+  if (!match) {
+    return str;
+  }
 
-  var data = match[3];
+  const data = match[3];
 
   if (match[2]) {
     // base64
@@ -88,13 +90,17 @@ export const cleanupOutData = (data, params, command) => {
     delimiter = ' ';
 
     // no extra space in front of first number
-    if (i == 0) delimiter = '';
+    if (i == 0) {
+      delimiter = '';
+    }
 
     // no extra space after arc command flags (large-arc and sweep flags)
     // a20 60 45 0 1 30 20 → a20 60 45 0130 20
     if (params.noSpaceAfterFlags && (command == 'A' || command == 'a')) {
-      var pos = i % 7;
-      if (pos == 4 || pos == 5) delimiter = '';
+      const pos = i % 7;
+      if (pos == 4 || pos == 5) {
+        delimiter = '';
+      }
     }
 
     // remove floating-point numbers leading zeros
diff --git a/lib/xast.js b/lib/xast.js
index 213da728..ff98c65b 100644
--- a/lib/xast.js
+++ b/lib/xast.js
@@ -1,13 +1,13 @@
-import { selectAll, selectOne, is } from 'css-select';
+import { is, selectAll, selectOne } from 'css-select';
 import { createAdapter } from './svgo/css-select-adapter.js';
 
 /**
  * @typedef {import('css-select').Options<XastNode & { children?: any }, XastElement>} Options
+ * @typedef {import('./types.js').Visitor} Visitor
+ * @typedef {import('./types.js').XastChild} XastChild
  * @typedef {import('./types.js').XastElement} XastElement
  * @typedef {import('./types.js').XastNode} XastNode
- * @typedef {import('./types.js').XastChild} XastChild
  * @typedef {import('./types.js').XastParent} XastParent
- * @typedef {import('./types.js').Visitor} Visitor
  */
 
 /**
diff --git a/lib/xast.test.js b/lib/xast.test.js
index 5ed35214..925dbe02 100644
--- a/lib/xast.test.js
+++ b/lib/xast.test.js
@@ -1,10 +1,10 @@
+import { detachNodeFromParent, visit, visitSkip } from './xast.js';
+
 /**
  * @typedef {import('./types.js').XastElement} XastElement
  * @typedef {import('./types.js').XastRoot} XastRoot
  */
 
-import { visit, visitSkip, detachNodeFromParent } from './xast.js';
-
 /**
  * @param {XastElement[]} children
  * @returns {XastRoot}
diff --git a/package.json b/package.json
index 5c7f3a2d..576b5ba6 100644
--- a/package.json
+++ b/package.json
@@ -133,7 +133,7 @@
     "pixelmatch": "^7.1.0",
     "playwright": "^1.51.1",
     "pngjs": "^7.0.0",
-    "prettier": "^3.2.5",
+    "prettier": "^3.5.3",
     "rimraf": "^5.0.7",
     "rollup": "^4.22.4",
     "tar-stream": "^3.1.7",
diff --git a/plugins/_path.js b/plugins/_path.js
index 960dd27b..ea2dd0b6 100644
--- a/plugins/_path.js
+++ b/plugins/_path.js
@@ -24,7 +24,7 @@ import { parsePathData, stringifyPathData } from '../lib/path.js';
  */
 
 /** @type {[number, number]} */
-var prevCtrlPoint;
+let prevCtrlPoint;
 
 /**
  * Convert path string to JS representation.
@@ -34,7 +34,10 @@ var prevCtrlPoint;
  */
 export const path2js = (path) => {
   // @ts-expect-error legacy
-  if (path.pathJS) return path.pathJS;
+  if (path.pathJS) {
+    // @ts-expect-error legacy
+    return path.pathJS;
+  }
   /** @type {PathDataItem[]} */
   const pathData = []; // JS representation of the path data
   const newPathData = parsePathData(path.attributes.d);
@@ -59,8 +62,8 @@ export const path2js = (path) => {
 const convertRelativeToAbsolute = (data) => {
   /** @type {PathDataItem[]} */
   const newData = [];
-  let start = [0, 0];
-  let cursor = [0, 0];
+  const start = [0, 0];
+  const cursor = [0, 0];
 
   for (let { command, args } of data) {
     args = args.slice();
@@ -259,8 +262,9 @@ export const intersects = function (path1, path2) {
         );
       });
     })
-  )
+  ) {
     return false;
+  }
 
   // Get a convex hull from points of each subpath. Has the most complexity O(n·log n).
   const hullNest1 = points1.list.map(convexHull);
@@ -268,15 +272,19 @@ export const intersects = function (path1, path2) {
 
   // Check intersection of every subpath of the first path with every subpath of the second.
   return hullNest1.some(function (hull1) {
-    if (hull1.list.length < 3) return false;
+    if (hull1.list.length < 3) {
+      return false;
+    }
 
     return hullNest2.some(function (hull2) {
-      if (hull2.list.length < 3) return false;
+      if (hull2.list.length < 3) {
+        return false;
+      }
 
-      var simplex = [getSupport(hull1, hull2, [1, 0])], // create the initial simplex
-        direction = minus(simplex[0]); // set the direction to point towards the origin
+      const simplex = [getSupport(hull1, hull2, [1, 0])]; // create the initial simplex
+      const direction = minus(simplex[0]); // set the direction to point towards the origin
 
-      var iterations = 1e4; // infinite loop protection, 10 000 iterations is more than enough
+      let iterations = 1e4; // infinite loop protection, 10 000 iterations is more than enough
 
       while (true) {
         if (iterations-- == 0) {
@@ -288,9 +296,13 @@ export const intersects = function (path1, path2) {
         // add a new point
         simplex.push(getSupport(hull1, hull2, direction));
         // see if the new point was on the correct side of the origin
-        if (dot(direction, simplex[simplex.length - 1]) <= 0) return false;
+        if (dot(direction, simplex[simplex.length - 1]) <= 0) {
+          return false;
+        }
         // process the simplex
-        if (processSimplex(simplex, direction)) return true;
+        if (processSimplex(simplex, direction)) {
+          return true;
+        }
       }
     });
   });
@@ -316,16 +328,16 @@ export const intersects = function (path1, path2) {
    * @returns {number[]}
    */
   function supportPoint(polygon, direction) {
-    var index =
-        direction[1] >= 0
-          ? direction[0] < 0
-            ? polygon.maxY
-            : polygon.maxX
-          : direction[0] < 0
-            ? polygon.minX
-            : polygon.minY,
-      max = -Infinity,
-      value;
+    let index =
+      direction[1] >= 0
+        ? direction[0] < 0
+          ? polygon.maxY
+          : polygon.maxX
+        : direction[0] < 0
+          ? polygon.minX
+          : polygon.minY;
+    let max = -Infinity;
+    let value;
     while ((value = dot(polygon.list[index], direction)) > max) {
       max = value;
       index = ++index % polygon.list.length;
@@ -343,10 +355,10 @@ function processSimplex(simplex, direction) {
   // we only need to handle to 1-simplex and 2-simplex
   if (simplex.length == 2) {
     // 1-simplex
-    let a = simplex[1],
-      b = simplex[0],
-      AO = minus(simplex[1]),
-      AB = sub(b, a);
+    const a = simplex[1];
+    const b = simplex[0];
+    const AO = minus(simplex[1]);
+    const AB = sub(b, a);
     // AO is in the same direction as AB
     if (dot(AO, AB) > 0) {
       // get the vector perpendicular to AB facing O
@@ -358,14 +370,14 @@ function processSimplex(simplex, direction) {
     }
   } else {
     // 2-simplex
-    let a = simplex[2], // [a, b, c] = simplex
-      b = simplex[1],
-      c = simplex[0],
-      AB = sub(b, a),
-      AC = sub(c, a),
-      AO = minus(a),
-      ACB = orth(AB, AC), // the vector perpendicular to AB facing away from C
-      ABC = orth(AC, AB); // the vector perpendicular to AC facing away from B
+    const a = simplex[2]; // [a, b, c] = simplex
+    const b = simplex[1];
+    const c = simplex[0];
+    const AB = sub(b, a);
+    const AC = sub(c, a);
+    const AO = minus(a);
+    const ACB = orth(AB, AC); // the vector perpendicular to AB facing away from C
+    const ABC = orth(AC, AB); // the vector perpendicular to AC facing away from B
 
     if (dot(ACB, AO) > 0) {
       if (dot(AB, AO) > 0) {
@@ -388,7 +400,9 @@ function processSimplex(simplex, direction) {
         simplex.splice(0, 2); // simplex = [a]
       }
     } // region 7
-    else return true;
+    else {
+      return true;
+    }
   }
   return false;
 }
@@ -425,7 +439,7 @@ function dot(v1, v2) {
  * @returns {number[]}
  */
 function orth(v, from) {
-  var o = [-v[1], v[0]];
+  const o = [-v[1], v[0]];
   return dot(o, minus(from)) < 0 ? minus(o) : o;
 }
 
@@ -477,10 +491,10 @@ function gatherPoints(pathData) {
       points.list.length === 0
         ? { list: [], minX: 0, minY: 0, maxX: 0, maxY: 0 }
         : points.list[points.list.length - 1];
-    let prev = i === 0 ? null : pathData[i - 1];
+    const prev = i === 0 ? null : pathData[i - 1];
     let basePoint =
       subPath.list.length === 0 ? null : subPath.list[subPath.list.length - 1];
-    let data = pathDataItem.args;
+    const data = pathDataItem.args;
     let ctrlPoint = basePoint;
 
     // TODO fix null hack
@@ -580,7 +594,7 @@ function gatherPoints(pathData) {
         if (basePoint != null) {
           // Convert the arc to Bézier curves and use the same approximation
           // @ts-expect-error no idea what's going on here
-          var curves = a2c.apply(0, basePoint.concat(data));
+          const curves = a2c.apply(0, basePoint.concat(data));
           for (
             var cData;
             (cData = curves.splice(0, 6).map(toAbsolute)).length;
@@ -600,14 +614,18 @@ function gatherPoints(pathData) {
               0.5 * (cData[2] + cData[4]),
               0.5 * (cData[3] + cData[5]),
             ]);
-            if (curves.length) addPoint(subPath, (basePoint = cData.slice(-2)));
+            if (curves.length) {
+              addPoint(subPath, (basePoint = cData.slice(-2)));
+            }
           }
         }
         break;
     }
 
     // Save final command coordinates
-    if (data.length >= 2) addPoint(subPath, data.slice(-2));
+    if (data.length >= 2) {
+      addPoint(subPath, data.slice(-2));
+    }
   }
 
   return points;
@@ -626,9 +644,9 @@ function convexHull(points) {
     return a[0] == b[0] ? a[1] - b[1] : a[0] - b[0];
   });
 
-  var lower = [],
-    minY = 0,
-    bottom = 0;
+  const lower = [];
+  let minY = 0;
+  let bottom = 0;
   for (let i = 0; i < points.list.length; i++) {
     while (
       lower.length >= 2 &&
@@ -644,9 +662,9 @@ function convexHull(points) {
     lower.push(points.list[i]);
   }
 
-  var upper = [],
-    maxY = points.list.length - 1,
-    top = 0;
+  const upper = [];
+  let maxY = points.list.length - 1;
+  let top = 0;
   for (let i = points.list.length; i--; ) {
     while (
       upper.length >= 2 &&
@@ -748,17 +766,17 @@ const a2c = (
     y1 = rotateY(x1, y1, -rad);
     x2 = rotateX(x2, y2, -rad);
     y2 = rotateY(x2, y2, -rad);
-    var x = (x1 - x2) / 2,
-      y = (y1 - y2) / 2;
-    var h = (x * x) / (rx * rx) + (y * y) / (ry * ry);
+    const x = (x1 - x2) / 2;
+    const y = (y1 - y2) / 2;
+    let h = (x * x) / (rx * rx) + (y * y) / (ry * ry);
     if (h > 1) {
       h = Math.sqrt(h);
       rx = h * rx;
       ry = h * ry;
     }
-    var rx2 = rx * rx;
-    var ry2 = ry * ry;
-    var k =
+    const rx2 = rx * rx;
+    const ry2 = ry * ry;
+    const k =
       (large_arc_flag == sweep_flag ? -1 : 1) *
       Math.sqrt(
         Math.abs(
@@ -786,11 +804,11 @@ const a2c = (
     cx = recursive[2];
     cy = recursive[3];
   }
-  var df = f2 - f1;
+  let df = f2 - f1;
   if (Math.abs(df) > _120) {
-    var f2old = f2,
-      x2old = x2,
-      y2old = y2;
+    const f2old = f2;
+    const x2old = x2;
+    const y2old = y2;
     f2 = f1 + _120 * (sweep_flag && f2 > f1 ? 1 : -1);
     x2 = cx + rx * Math.cos(f2);
     y2 = cy + ry * Math.sin(f2);
@@ -802,27 +820,27 @@ const a2c = (
     ]);
   }
   df = f2 - f1;
-  var c1 = Math.cos(f1),
-    s1 = Math.sin(f1),
-    c2 = Math.cos(f2),
-    s2 = Math.sin(f2),
-    t = Math.tan(df / 4),
-    hx = (4 / 3) * rx * t,
-    hy = (4 / 3) * ry * t,
-    m = [
-      -hx * s1,
-      hy * c1,
-      x2 + hx * s2 - x1,
-      y2 - hy * c2 - y1,
-      x2 - x1,
-      y2 - y1,
-    ];
+  const c1 = Math.cos(f1);
+  const s1 = Math.sin(f1);
+  const c2 = Math.cos(f2);
+  const s2 = Math.sin(f2);
+  const t = Math.tan(df / 4);
+  const hx = (4 / 3) * rx * t;
+  const hy = (4 / 3) * ry * t;
+  const m = [
+    -hx * s1,
+    hy * c1,
+    x2 + hx * s2 - x1,
+    y2 - hy * c2 - y1,
+    x2 - x1,
+    y2 - y1,
+  ];
   if (recursive) {
     return m.concat(res);
   } else {
     res = m.concat(res);
-    var newres = [];
-    for (var i = 0, n = res.length; i < n; i++) {
+    const newres = [];
+    for (let i = 0, n = res.length; i < n; i++) {
       newres[i] =
         i % 2
           ? rotateY(res[i - 1], res[i], rad)
diff --git a/plugins/_transforms.js b/plugins/_transforms.js
index 8565002a..303205b3 100644
--- a/plugins/_transforms.js
+++ b/plugins/_transforms.js
@@ -514,10 +514,10 @@ const transformToMatrix = (transform) => {
       ];
     case 'rotate':
       // [cos(a), sin(a), -sin(a), cos(a), x, y]
-      var cos = mth.cos(transform.data[0]),
-        sin = mth.sin(transform.data[0]),
-        cx = transform.data[1] || 0,
-        cy = transform.data[2] || 0;
+      var cos = mth.cos(transform.data[0]);
+      var sin = mth.sin(transform.data[0]);
+      var cx = transform.data[1] || 0;
+      var cy = transform.data[2] || 0;
       return [
         cos,
         sin,
@@ -719,13 +719,13 @@ const round = (data) => {
  */
 const smartRound = (precision, data) => {
   for (
-    var i = data.length,
+    let i = data.length,
       tolerance = +Math.pow(0.1, precision).toFixed(precision);
     i--;
 
   ) {
     if (toFixed(data[i], precision) !== data[i]) {
-      var rounded = +data[i].toFixed(precision - 1);
+      const rounded = +data[i].toFixed(precision - 1);
       data[i] =
         +Math.abs(rounded - data[i]).toFixed(precision + 1) >= tolerance
           ? +data[i].toFixed(precision)
diff --git a/plugins/addAttributesToSVGElement.js b/plugins/addAttributesToSVGElement.js
index bec455a6..c1337261 100644
--- a/plugins/addAttributesToSVGElement.js
+++ b/plugins/addAttributesToSVGElement.js
@@ -7,7 +7,7 @@
 export const name = 'addAttributesToSVGElement';
 export const description = 'adds attributes to an outer <svg> element';
 
-var ENOCLS = `Error in plugin "addAttributesToSVGElement": absent parameters.
+const ENOCLS = `Error in plugin "addAttributesToSVGElement": absent parameters.
 It should have a list of "attributes" or one "attribute".
 Config example:
 
diff --git a/plugins/addClassesToSVGElement.js b/plugins/addClassesToSVGElement.js
index 55e960af..64c995a1 100644
--- a/plugins/addClassesToSVGElement.js
+++ b/plugins/addClassesToSVGElement.js
@@ -10,7 +10,7 @@
 export const name = 'addClassesToSVGElement';
 export const description = 'adds classnames to an outer <svg> element';
 
-var ENOCLS = `Error in plugin "addClassesToSVGElement": absent parameters.
+const ENOCLS = `Error in plugin "addClassesToSVGElement": absent parameters.
 It should have a list of classes in "classNames" or one "className".
 Config example:
 
diff --git a/plugins/applyTransforms.js b/plugins/applyTransforms.js
index b848971a..d1a18498 100644
--- a/plugins/applyTransforms.js
+++ b/plugins/applyTransforms.js
@@ -1,13 +1,13 @@
 import { path2js } from './_path.js';
 import {
-  transformsMultiply,
   transform2js,
   transformArc,
+  transformsMultiply,
 } from './_transforms.js';
-import { referencesProps, attrsGroupsDefaults } from './_collections.js';
+import { attrsGroupsDefaults, referencesProps } from './_collections.js';
 import { collectStylesheet, computeStyle } from '../lib/style.js';
 
-import { removeLeadingZero, includesUrlReference } from '../lib/svgo/tools.js';
+import { includesUrlReference, removeLeadingZero } from '../lib/svgo/tools.js';
 
 /**
  * @typedef {import('../lib/types.js').PathDataItem} PathDataItem
diff --git a/plugins/cleanupIds.js b/plugins/cleanupIds.js
index 599ef508..3d10efce 100644
--- a/plugins/cleanupIds.js
+++ b/plugins/cleanupIds.js
@@ -1,5 +1,5 @@
 import { visitSkip } from '../lib/xast.js';
-import { hasScripts, findReferences } from '../lib/svgo/tools.js';
+import { findReferences, hasScripts } from '../lib/svgo/tools.js';
 
 /**
  * @typedef {import('../lib/types.js').XastElement} XastElement
@@ -224,7 +224,7 @@ export const fn = (_root, params) => {
             // replace referenced IDs with the minified ones
             if (minify && isIdPreserved(id) === false) {
               /** @type {?string} */
-              let currentIdString = null;
+              let currentIdString;
               do {
                 currentId = generateId(currentId);
                 currentIdString = getIdString(currentId);
diff --git a/plugins/cleanupListOfValues.js b/plugins/cleanupListOfValues.js
index 9f961ab3..e7ec90d8 100644
--- a/plugins/cleanupListOfValues.js
+++ b/plugins/cleanupListOfValues.js
@@ -64,7 +64,7 @@ export const fn = (_root, params) => {
         // round it to the fixed precision
         let num = Number(Number(match[1]).toFixed(floatPrecision));
         /** @type {any} */
-        let matchedUnit = match[3] || '';
+        const matchedUnit = match[3] || '';
         /** @type {'' | keyof typeof absoluteLengths} */
         let units = matchedUnit;
 
diff --git a/plugins/cleanupNumericValues.js b/plugins/cleanupNumericValues.js
index 392c658c..eefdaae0 100644
--- a/plugins/cleanupNumericValues.js
+++ b/plugins/cleanupNumericValues.js
@@ -10,7 +10,7 @@ import { removeLeadingZero } from '../lib/svgo/tools.js';
 
 export const name = 'cleanupNumericValues';
 export const description =
-  'rounds numeric values to the fixed precision, removes default ‘px’ units';
+  'rounds numeric values to the fixed precision, removes default "px" units';
 
 const regNumericValues =
   /^([-+]?\d*\.?\d+([eE][-+]?\d+)?)(px|pt|pc|mm|cm|m|in|ft|em|ex|%)?$/;
@@ -26,8 +26,7 @@ const absoluteLengths = {
 };
 
 /**
- * Round numeric values to the fixed precision,
- * remove default 'px' units.
+ * Round numeric values to the fixed precision, remove default 'px' units.
  *
  * @author Kir Belevich
  *
@@ -69,7 +68,7 @@ export const fn = (_root, params) => {
             // round it to the fixed precision
             let num = Number(Number(match[1]).toFixed(floatPrecision));
             /** @type {any} */
-            let matchedUnit = match[3] || '';
+            const matchedUnit = match[3] || '';
             /** @type {'' | keyof typeof absoluteLengths} */
             let units = matchedUnit;
 
diff --git a/plugins/collapseGroups.js b/plugins/collapseGroups.js
index 179e7ac0..b49fd303 100644
--- a/plugins/collapseGroups.js
+++ b/plugins/collapseGroups.js
@@ -1,5 +1,5 @@
-import { computeStyle, collectStylesheet } from '../lib/style.js';
-import { inheritableAttrs, elemsGroups } from './_collections.js';
+import { collectStylesheet, computeStyle } from '../lib/style.js';
+import { elemsGroups, inheritableAttrs } from './_collections.js';
 
 /**
  * @typedef {import('../lib/types.js').Plugin} Plugin
diff --git a/plugins/convertColors.js b/plugins/convertColors.js
index ad6f6a34..423b2dfc 100644
--- a/plugins/convertColors.js
+++ b/plugins/convertColors.js
@@ -121,9 +121,9 @@ export const fn = (_root, params) => {
 
             // convert rgb() to long hex
             if (rgb2hex) {
-              let match = val.match(regRGB);
+              const match = val.match(regRGB);
               if (match != null) {
-                let nums = match.slice(1, 4).map((m) => {
+                const nums = match.slice(1, 4).map((m) => {
                   let n;
                   if (m.indexOf('%') > -1) {
                     n = Math.round(parseFloat(m) * 2.55);
@@ -146,7 +146,7 @@ export const fn = (_root, params) => {
 
             // convert long hex to short hex
             if (shorthex) {
-              let match = regHEX.exec(val);
+              const match = regHEX.exec(val);
               if (match != null) {
                 val = '#' + match[0][1] + match[0][3] + match[0][5];
               }
diff --git a/plugins/convertOneStopGradients.js b/plugins/convertOneStopGradients.js
index ed32e598..67203443 100644
--- a/plugins/convertOneStopGradients.js
+++ b/plugins/convertOneStopGradients.js
@@ -1,10 +1,10 @@
 import { attrsGroupsDefaults, colorsProps } from './_collections.js';
 import {
   detachNodeFromParent,
-  querySelectorAll,
   querySelector,
+  querySelectorAll,
 } from '../lib/xast.js';
-import { computeStyle, collectStylesheet } from '../lib/style.js';
+import { collectStylesheet, computeStyle } from '../lib/style.js';
 
 /**
  * @typedef {import('../lib/types.js').Plugin} Plugin
@@ -64,7 +64,7 @@ export const fn = (root) => {
         });
 
         const href = node.attributes['xlink:href'] || node.attributes['href'];
-        let effectiveNode =
+        const effectiveNode =
           stops.length === 0 && href != null && href.startsWith('#')
             ? querySelector(root, href)
             : node;
diff --git a/plugins/convertPathData.js b/plugins/convertPathData.js
index 3e385b52..8a2ca278 100644
--- a/plugins/convertPathData.js
+++ b/plugins/convertPathData.js
@@ -1,4 +1,4 @@
-import { path2js, js2path } from './_path.js';
+import { js2path, path2js } from './_path.js';
 import { pathElems } from './_collections.js';
 import { applyTransforms } from './applyTransforms.js';
 import { collectStylesheet, computeStyle } from '../lib/style.js';
@@ -217,8 +217,8 @@ export const fn = (root, params) => {
  * @returns {PathDataItem[]}
  */
 const convertToRelative = (pathData) => {
-  let start = [0, 0];
-  let cursor = [0, 0];
+  const start = [0, 0];
+  const cursor = [0, 0];
   let prevCoords = [0, 0];
 
   for (let i = 0; i < pathData.length; i += 1) {
@@ -413,8 +413,8 @@ function filters(
     let next = path[index + 1];
 
     if (command !== 'Z' && command !== 'z') {
-      var sdata = data,
-        circle;
+      let sdata = data;
+      let circle;
 
       if (command === 's') {
         sdata = [0, 0].concat(data);
@@ -434,31 +434,31 @@ function filters(
         isConvex(sdata) &&
         (circle = findCircle(sdata))
       ) {
-        var r = roundData([circle.radius])[0],
-          angle = findArcAngle(sdata, circle),
-          sweep = sdata[5] * sdata[0] - sdata[4] * sdata[1] > 0 ? 1 : 0,
-          /** @type {PathDataItem} */
-          arc = {
-            command: 'a',
-            args: [r, r, 0, 0, sweep, sdata[4], sdata[5]],
-            // @ts-expect-error
-            coords: item.coords.slice(),
-            // @ts-expect-error
-            base: item.base,
-          },
-          /** @type {PathDataItem[]} */
-          output = [arc],
-          // relative coordinates to adjust the found circle
-          /** @type {Point} */
-          relCenter = [
-            circle.center[0] - sdata[4],
-            circle.center[1] - sdata[5],
-          ],
-          relCircle = { center: relCenter, radius: circle.radius },
-          arcCurves = [item],
-          hasPrev = 0,
-          suffix = '',
-          nextLonghand;
+        const r = roundData([circle.radius])[0];
+        let angle = findArcAngle(sdata, circle);
+        const sweep = sdata[5] * sdata[0] - sdata[4] * sdata[1] > 0 ? 1 : 0;
+        /** @type {PathDataItem} */
+        let arc = {
+          command: 'a',
+          args: [r, r, 0, 0, sweep, sdata[4], sdata[5]],
+          // @ts-expect-error
+          coords: item.coords.slice(),
+          // @ts-expect-error
+          base: item.base,
+        };
+        /** @type {PathDataItem[]} */
+        const output = [arc];
+        // relative coordinates to adjust the found circle
+        /** @type {Point} */
+        const relCenter = [
+          circle.center[0] - sdata[4],
+          circle.center[1] - sdata[5],
+        ];
+        const relCircle = { center: relCenter, radius: circle.radius };
+        const arcCurves = [item];
+        let hasPrev = 0;
+        let suffix = '';
+        let nextLonghand;
 
         if (
           (prev.command == 'c' &&
@@ -473,8 +473,8 @@ function filters(
           arc.args[5] = arc.coords[0] - arc.base[0];
           // @ts-expect-error
           arc.args[6] = arc.coords[1] - arc.base[1];
-          var prevData = prev.command == 'a' ? prev.sdata : prev.args;
-          var prevAngle = findArcAngle(prevData, {
+          const prevData = prev.command == 'a' ? prev.sdata : prev.args;
+          const prevAngle = findArcAngle(prevData, {
             center: [
               prevData[4] + circle.center[0],
               prevData[5] + circle.center[1],
@@ -482,7 +482,9 @@ function filters(
             radius: circle.radius,
           });
           angle += prevAngle;
-          if (angle > Math.PI) arc.args[3] = 1;
+          if (angle > Math.PI) {
+            arc.args[3] = 1;
+          }
           hasPrev = 1;
         }
 
@@ -492,7 +494,7 @@ function filters(
           (next = path[++j]) && (next.command === 'c' || next.command === 's');
 
         ) {
-          var nextData = next.args;
+          let nextData = next.args;
           if (next.command == 's') {
             nextLonghand = makeLonghand(
               { command: 's', args: next.args.slice() },
@@ -504,8 +506,12 @@ function filters(
           }
           if (isConvex(nextData) && isArc(nextData, relCircle)) {
             angle += findArcAngle(nextData, relCircle);
-            if (angle - 2 * Math.PI > 1e-3) break; // more than 360°
-            if (angle > Math.PI) arc.args[3] = 1;
+            if (angle - 2 * Math.PI > 1e-3) {
+              break;
+            } // more than 360°
+            if (angle > Math.PI) {
+              arc.args[3] = 1;
+            }
             arcCurves.push(next);
             if (2 * Math.PI - angle > 1e-3) {
               // less than 360°
@@ -550,7 +556,9 @@ function filters(
             }
             relCenter[0] -= nextData[4];
             relCenter[1] -= nextData[5];
-          } else break;
+          } else {
+            break;
+          }
         }
 
         if ((stringify(output) + suffix).length < stringify(arcCurves).length) {
@@ -558,7 +566,7 @@ function filters(
             makeLonghand(path[j], path[j - 1].args);
           }
           if (hasPrev) {
-            var prevArc = output.shift();
+            const prevArc = output.shift();
             // @ts-expect-error
             roundData(prevArc.args);
             // @ts-expect-error
@@ -580,7 +588,9 @@ function filters(
             // filter out consumed next items
             path.splice(index + 1, arcCurves.length - 1 - hasPrev, ...output);
           }
-          if (!arc) return false;
+          if (!arc) {
+            return false;
+          }
           command = 'a';
           data = arc.args;
           // @ts-expect-error
@@ -600,7 +610,7 @@ function filters(
           command === 's' ||
           command === 'c'
         ) {
-          for (var i = data.length; i--; ) {
+          for (let i = data.length; i--; ) {
             // @ts-expect-error
             data[i] += item.base[i % 2] - relSubpoint[i % 2];
           }
@@ -618,9 +628,11 @@ function filters(
         }
         roundData(data);
 
-        if (command == 'h') relSubpoint[0] += data[0];
-        else if (command == 'v') relSubpoint[1] += data[0];
-        else {
+        if (command == 'h') {
+          relSubpoint[0] += data[0];
+        } else if (command == 'v') {
+          relSubpoint[1] += data[0];
+        } else {
           relSubpoint[0] += data[data.length - 2];
           relSubpoint[1] += data[data.length - 1];
         }
@@ -656,11 +668,15 @@ function filters(
           (command === 'c' && isCurveStraightLine(data)) ||
           (command === 's' && isCurveStraightLine(sdata))
         ) {
-          if (next && next.command == 's') makeLonghand(next, data); // fix up next curve
+          if (next && next.command == 's') {
+            makeLonghand(next, data);
+          } // fix up next curve
           command = 'l';
           data = data.slice(-2);
         } else if (command === 'q' && isCurveStraightLine(data)) {
-          if (next && next.command == 't') makeLonghand(next, data); // fix up next curve
+          if (next && next.command == 't') {
+            makeLonghand(next, data);
+          } // fix up next curve
           command = 'l';
           data = data.slice(-2);
         } else if (
@@ -708,12 +724,14 @@ function filters(
               y1 + y2 - item.base[1],
             );
             roundData(newData);
-            const originalLength = cleanupOutData(data, params).length,
-              newLength = cleanupOutData(newData, params).length;
+            const originalLength = cleanupOutData(data, params).length;
+            const newLength = cleanupOutData(newData, params).length;
             if (newLength < originalLength) {
               command = 'q';
               data = newData;
-              if (next && next.command == 's') makeLonghand(next, data); // fix up next curve
+              if (next && next.command == 's') {
+                makeLonghand(next, data);
+              } // fix up next curve
             }
           }
         }
@@ -877,7 +895,9 @@ function filters(
       // z resets coordinates
       relSubpoint[0] = pathBase[0];
       relSubpoint[1] = pathBase[1];
-      if (prev.command === 'Z' || prev.command === 'z') return false;
+      if (prev.command === 'Z' || prev.command === 'z') {
+        return false;
+      }
     }
     if (
       (command === 'Z' || command === 'z') &&
@@ -887,8 +907,9 @@ function filters(
       Math.abs(item.base[0] - item.coords[0]) < error / 10 &&
       // @ts-expect-error
       Math.abs(item.base[1] - item.coords[1]) < error / 10
-    )
+    ) {
       return false;
+    }
 
     if (command === 'q') {
       // @ts-expect-error
@@ -919,19 +940,21 @@ function filters(
  * @returns {PathDataItem[]}
  */
 function convertToMixed(path, params) {
-  var prev = path[0];
+  let prev = path[0];
 
   path = path.filter(function (item, index) {
-    if (index == 0) return true;
+    if (index == 0) {
+      return true;
+    }
     if (item.command === 'Z' || item.command === 'z') {
       prev = item;
       return true;
     }
 
-    var command = item.command,
-      data = item.args,
-      adata = data.slice(),
-      rdata = data.slice();
+    const command = item.command;
+    const data = item.args;
+    const adata = data.slice();
+    const rdata = data.slice();
 
     if (
       command === 'm' ||
@@ -941,7 +964,7 @@ function convertToMixed(path, params) {
       command === 's' ||
       command === 'c'
     ) {
-      for (var i = adata.length; i--; ) {
+      for (let i = adata.length; i--; ) {
         // @ts-expect-error
         adata[i] += item.base[i % 2];
       }
@@ -961,8 +984,8 @@ function convertToMixed(path, params) {
     roundData(adata);
     roundData(rdata);
 
-    var absoluteDataStr = cleanupOutData(adata, params),
-      relativeDataStr = cleanupOutData(rdata, params);
+    const absoluteDataStr = cleanupOutData(adata, params);
+    const relativeDataStr = cleanupOutData(rdata, params);
 
     // Convert to absolute coordinates if it's shorter or forceAbsolutePath is true.
     // v-20 -> V0
@@ -1002,7 +1025,7 @@ function convertToMixed(path, params) {
  * @returns {boolean}
  */
 function isConvex(data) {
-  var center = getIntersection([
+  const center = getIntersection([
     0,
     0,
     data[2],
@@ -1030,19 +1053,21 @@ function isConvex(data) {
  */
 function getIntersection(coords) {
   // Prev line equation parameters.
-  var a1 = coords[1] - coords[3], // y1 - y2
-    b1 = coords[2] - coords[0], // x2 - x1
-    c1 = coords[0] * coords[3] - coords[2] * coords[1], // x1 * y2 - x2 * y1
-    // Next line equation parameters
-    a2 = coords[5] - coords[7], // y1 - y2
-    b2 = coords[6] - coords[4], // x2 - x1
-    c2 = coords[4] * coords[7] - coords[5] * coords[6], // x1 * y2 - x2 * y1
-    denom = a1 * b2 - a2 * b1;
+  const a1 = coords[1] - coords[3]; // y1 - y2
+  const b1 = coords[2] - coords[0]; // x2 - x1
+  const c1 = coords[0] * coords[3] - coords[2] * coords[1]; // x1 * y2 - x2 * y1
+  // Next line equation parameters
+  const a2 = coords[5] - coords[7]; // y1 - y2
+  const b2 = coords[6] - coords[4]; // x2 - x1
+  const c2 = coords[4] * coords[7] - coords[5] * coords[6]; // x1 * y2 - x2 * y1
+  const denom = a1 * b2 - a2 * b1;
 
-  if (!denom) return; // parallel lines haven't an intersection
+  if (!denom) {
+    return;
+  } // parallel lines haven't an intersection
 
   /** @type {Point} */
-  var cross = [(b1 * c2 - b2 * c1) / denom, (a1 * c2 - a2 * c1) / -denom];
+  const cross = [(b1 * c2 - b2 * c1) / denom, (a1 * c2 - a2 * c1) / -denom];
   if (
     !isNaN(cross[0]) &&
     !isNaN(cross[1]) &&
@@ -1083,7 +1108,7 @@ function strongRound(data) {
  * @returns {number[]}
  */
 function round(data) {
-  for (var i = data.length; i-- > 0; ) {
+  for (let i = data.length; i-- > 0; ) {
     data[i] = Math.round(data[i]);
   }
   return data;
@@ -1098,17 +1123,20 @@ function round(data) {
  */
 function isCurveStraightLine(data) {
   // Get line equation a·x + b·y + c = 0 coefficients a, b (c = 0) by start and end points.
-  var i = data.length - 2,
-    a = -data[i + 1], // y1 − y2 (y1 = 0)
-    b = data[i], // x2 − x1 (x1 = 0)
-    d = 1 / (a * a + b * b); // same part for all points
+  let i = data.length - 2;
+  const a = -data[i + 1]; // y1 − y2 (y1 = 0)
+  const b = data[i]; // x2 − x1 (x1 = 0)
+  const d = 1 / (a * a + b * b); // same part for all points
 
-  if (i <= 1 || !isFinite(d)) return false; // curve that ends at start point isn't the case
+  if (i <= 1 || !isFinite(d)) {
+    return false;
+  } // curve that ends at start point isn't the case
 
   // Distance from point (x0, y0) to the line is sqrt((c − a·x0 − b·y0)² / (a² + b²))
   while ((i -= 2) >= 0) {
-    if (Math.sqrt(Math.pow(a * data[i] + b * data[i + 1], 2) * d) > error)
+    if (Math.sqrt(Math.pow(a * data[i] + b * data[i + 1], 2) * d) > error) {
       return false;
+    }
   }
 
   return true;
@@ -1122,11 +1150,17 @@ function isCurveStraightLine(data) {
  * @returns {number | undefined}
  */
 function calculateSagitta(data) {
-  if (data[3] === 1) return undefined;
+  if (data[3] === 1) {
+    return undefined;
+  }
   const [rx, ry] = data;
-  if (Math.abs(rx - ry) > error) return undefined;
+  if (Math.abs(rx - ry) > error) {
+    return undefined;
+  }
   const chord = Math.hypot(data[5], data[6]);
-  if (chord > rx * 2) return undefined;
+  if (chord > rx * 2) {
+    return undefined;
+  }
   return rx - Math.sqrt(rx ** 2 - 0.25 * chord ** 2);
 }
 
@@ -1185,10 +1219,10 @@ function reflectPoint(controlPoint, base) {
  * @returns {Point}
  */
 function getCubicBezierPoint(curve, t) {
-  var sqrT = t * t,
-    cubT = sqrT * t,
-    mt = 1 - t,
-    sqrMt = mt * mt;
+  const sqrT = t * t;
+  const cubT = sqrT * t;
+  const mt = 1 - t;
+  const sqrMt = mt * mt;
 
   return [
     3 * sqrMt * t * curve[0] + 3 * mt * sqrT * curve[2] + cubT * curve[4],
@@ -1203,22 +1237,25 @@ function getCubicBezierPoint(curve, t) {
  * @returns {Circle | undefined}
  */
 function findCircle(curve) {
-  var midPoint = getCubicBezierPoint(curve, 1 / 2),
-    m1 = [midPoint[0] / 2, midPoint[1] / 2],
-    m2 = [(midPoint[0] + curve[4]) / 2, (midPoint[1] + curve[5]) / 2],
-    center = getIntersection([
-      m1[0],
-      m1[1],
-      m1[0] + m1[1],
-      m1[1] - m1[0],
-      m2[0],
-      m2[1],
-      m2[0] + (m2[1] - midPoint[1]),
-      m2[1] - (m2[0] - midPoint[0]),
-    ]),
-    radius = center && getDistance([0, 0], center),
+  const midPoint = getCubicBezierPoint(curve, 1 / 2);
+  const m1 = [midPoint[0] / 2, midPoint[1] / 2];
+  const m2 = [(midPoint[0] + curve[4]) / 2, (midPoint[1] + curve[5]) / 2];
+  const center = getIntersection([
+    m1[0],
+    m1[1],
+    m1[0] + m1[1],
+    m1[1] - m1[0],
+    m2[0],
+    m2[1],
+    m2[0] + (m2[1] - midPoint[1]),
+    m2[1] - (m2[0] - midPoint[0]),
+  ]);
+  const radius = center && getDistance([0, 0], center);
+  const tolerance = Math.min(
+    arcThreshold * error,
     // @ts-expect-error
-    tolerance = Math.min(arcThreshold * error, (arcTolerance * radius) / 100);
+    (arcTolerance * radius) / 100,
+  );
 
   if (
     center &&
@@ -1232,9 +1269,10 @@ function findCircle(curve) {
         ) <= tolerance
       );
     })
-  )
+  ) {
     // @ts-expect-error
     return { center: center, radius: radius };
+  }
 }
 
 /**
@@ -1245,7 +1283,7 @@ function findCircle(curve) {
  * @returns {boolean}
  */
 function isArc(curve, circle) {
-  var tolerance = Math.min(
+  const tolerance = Math.min(
     arcThreshold * error,
     (arcTolerance * circle.radius) / 100,
   );
@@ -1282,10 +1320,10 @@ function isArcPrev(curve, circle) {
  * @returns {number}
  */
 function findArcAngle(curve, relCircle) {
-  var x1 = -relCircle.center[0],
-    y1 = -relCircle.center[1],
-    x2 = curve[4] - relCircle.center[0],
-    y2 = curve[5] - relCircle.center[1];
+  const x1 = -relCircle.center[0];
+  const y1 = -relCircle.center[1];
+  const x2 = curve[4] - relCircle.center[0];
+  const y2 = curve[5] - relCircle.center[1];
 
   return Math.acos(
     (x1 * x2 + y1 * y2) / Math.sqrt((x1 * x1 + y1 * y1) * (x2 * x2 + y2 * y2)),
@@ -1301,7 +1339,7 @@ function findArcAngle(curve, relCircle) {
  */
 function data2Path(params, pathData) {
   return pathData.reduce(function (pathString, item) {
-    var strData = '';
+    let strData = '';
     if (item.args) {
       strData = cleanupOutData(roundData(item.args.slice()), params);
     }
diff --git a/plugins/convertShapeToPath.js b/plugins/convertShapeToPath.js
index 44da7e37..3a6ad50a 100644
--- a/plugins/convertShapeToPath.js
+++ b/plugins/convertShapeToPath.js
@@ -46,7 +46,9 @@ export const fn = (root, params) => {
           // Values like '100%' compute to NaN, thus running after
           // cleanupNumericValues when 'px' units has already been removed.
           // TODO: Calculate sizes from % and non-px units if possible.
-          if (Number.isNaN(x - y + width - height)) return;
+          if (Number.isNaN(x - y + width - height)) {
+            return;
+          }
           /** @type {PathDataItem[]} */
           const pathData = [
             { command: 'M', args: [x, y] },
@@ -69,7 +71,9 @@ export const fn = (root, params) => {
           const y1 = Number(node.attributes.y1 || '0');
           const x2 = Number(node.attributes.x2 || '0');
           const y2 = Number(node.attributes.y2 || '0');
-          if (Number.isNaN(x1 - y1 + x2 - y2)) return;
+          if (Number.isNaN(x1 - y1 + x2 - y2)) {
+            return;
+          }
           /** @type {PathDataItem[]} */
           const pathData = [
             { command: 'M', args: [x1, y1] },
diff --git a/plugins/convertStyleToAttrs.js b/plugins/convertStyleToAttrs.js
index 42189f1a..2691cabb 100644
--- a/plugins/convertStyleToAttrs.js
+++ b/plugins/convertStyleToAttrs.js
@@ -111,8 +111,8 @@ export const fn = (_root, params) => {
           if (styles.length) {
             styles = styles.filter(function (style) {
               if (style[0]) {
-                var prop = style[0].toLowerCase(),
-                  val = style[1];
+                const prop = style[0].toLowerCase();
+                let val = style[1];
 
                 if (rQuotedString.test(val)) {
                   val = val.slice(1, -1);
diff --git a/plugins/convertTransform.js b/plugins/convertTransform.js
index 0a86526e..09aaa1fe 100644
--- a/plugins/convertTransform.js
+++ b/plugins/convertTransform.js
@@ -205,12 +205,12 @@ const floatDigits = (n) => {
  * @returns {TransformItem[]}
  */
 const convertToShorts = (transforms, params) => {
-  for (var i = 0; i < transforms.length; i++) {
+  for (let i = 0; i < transforms.length; i++) {
     let transform = transforms[i];
 
     // convert matrix to the short aliases
     if (params.matrixToTransform && transform.name === 'matrix') {
-      var decomposed = matrixToTransform(transform, params);
+      const decomposed = matrixToTransform(transform, params);
       if (
         js2transform(decomposed, params).length <=
         js2transform([transform], params).length
diff --git a/plugins/inlineStyles.js b/plugins/inlineStyles.js
index f53105ea..07018cbb 100644
--- a/plugins/inlineStyles.js
+++ b/plugins/inlineStyles.js
@@ -2,9 +2,9 @@ import * as csstree from 'css-tree';
 import { syntax } from 'csso';
 import { attrsGroups, pseudoClasses } from './_collections.js';
 import {
-  visitSkip,
-  querySelectorAll,
   detachNodeFromParent,
+  querySelectorAll,
+  visitSkip,
 } from '../lib/xast.js';
 import { compareSpecificity, includesAttrSelector } from '../lib/style.js';
 
@@ -72,7 +72,7 @@ export const fn = (root, params) => {
    *   matchedElements?: XastElement[]
    * }[]}
    */
-  let selectors = [];
+  const selectors = [];
 
   return {
     element: {
diff --git a/plugins/mergePaths.js b/plugins/mergePaths.js
index 58cad7af..c009a130 100644
--- a/plugins/mergePaths.js
+++ b/plugins/mergePaths.js
@@ -1,5 +1,5 @@
 import { collectStylesheet, computeStyle } from '../lib/style.js';
-import { path2js, js2path, intersects } from './_path.js';
+import { intersects, js2path, path2js } from './_path.js';
 import { includesUrlReference } from '../lib/svgo/tools.js';
 
 /**
diff --git a/plugins/mergeStyles.js b/plugins/mergeStyles.js
index f3fa5d1a..0ed9d440 100644
--- a/plugins/mergeStyles.js
+++ b/plugins/mergeStyles.js
@@ -1,4 +1,4 @@
-import { visitSkip, detachNodeFromParent } from '../lib/xast.js';
+import { detachNodeFromParent, visitSkip } from '../lib/xast.js';
 
 /**
  * @typedef {import('../lib/types.js').Plugin} Plugin
diff --git a/plugins/prefixIds.js b/plugins/prefixIds.js
index d7109611..36ff877e 100644
--- a/plugins/prefixIds.js
+++ b/plugins/prefixIds.js
@@ -164,7 +164,7 @@ export const fn = (_root, params, info) => {
 
             const cssText = child.value;
             /** @type {?csstree.CssNode} */
-            let cssAst = null;
+            let cssAst;
             try {
               cssAst = csstree.parse(cssText, {
                 parseValue: true,
diff --git a/plugins/removeHiddenElems.js b/plugins/removeHiddenElems.js
index b89e4318..6af2a574 100644
--- a/plugins/removeHiddenElems.js
+++ b/plugins/removeHiddenElems.js
@@ -1,13 +1,13 @@
 import { elemsGroups } from './_collections.js';
 import {
+  detachNodeFromParent,
+  querySelector,
   visit,
   visitSkip,
-  querySelector,
-  detachNodeFromParent,
 } from '../lib/xast.js';
 import { collectStylesheet, computeStyle } from '../lib/style.js';
 import { parsePathData } from '../lib/path.js';
-import { hasScripts, findReferences } from '../lib/svgo/tools.js';
+import { findReferences, hasScripts } from '../lib/svgo/tools.js';
 
 /**
  * @typedef {import('../lib/types.js').XastChild} XastChild
@@ -183,7 +183,9 @@ export const fn = (root, params) => {
 
         if (node.name === 'use') {
           for (const attr of Object.keys(node.attributes)) {
-            if (attr !== 'href' && !attr.endsWith(':href')) continue;
+            if (attr !== 'href' && !attr.endsWith(':href')) {
+              continue;
+            }
             const value = node.attributes[attr];
             const id = value.slice(1);
 
diff --git a/plugins/removeNonInheritableGroupAttrs.js b/plugins/removeNonInheritableGroupAttrs.js
index e6d407a6..76a995f6 100644
--- a/plugins/removeNonInheritableGroupAttrs.js
+++ b/plugins/removeNonInheritableGroupAttrs.js
@@ -1,6 +1,6 @@
 import {
-  inheritableAttrs,
   attrsGroups,
+  inheritableAttrs,
   presentationNonInheritableGroupAttrs,
 } from './_collections.js';
 
@@ -10,7 +10,7 @@ import {
 
 export const name = 'removeNonInheritableGroupAttrs';
 export const description =
-  'removes non-inheritable group’s presentational attributes';
+  "removes non-inheritable group's presentational attributes";
 
 /**
  * Remove non-inheritable group's "presentation" attributes.
diff --git a/plugins/removeOffCanvasPaths.js b/plugins/removeOffCanvasPaths.js
index 3584d2f6..f5315b06 100644
--- a/plugins/removeOffCanvasPaths.js
+++ b/plugins/removeOffCanvasPaths.js
@@ -1,4 +1,4 @@
-import { visitSkip, detachNodeFromParent } from '../lib/xast.js';
+import { detachNodeFromParent, visitSkip } from '../lib/xast.js';
 import { parsePathData } from '../lib/path.js';
 import { intersects } from './_path.js';
 
diff --git a/plugins/removeUnknownsAndDefaults.js b/plugins/removeUnknownsAndDefaults.js
index afa88231..bc8b0515 100644
--- a/plugins/removeUnknownsAndDefaults.js
+++ b/plugins/removeUnknownsAndDefaults.js
@@ -1,11 +1,11 @@
 import {
-  elems,
   attrsGroups,
-  elemsGroups,
   attrsGroupsDefaults,
+  elems,
+  elemsGroups,
   presentationNonInheritableGroupAttrs,
 } from './_collections.js';
-import { visitSkip, detachNodeFromParent } from '../lib/xast.js';
+import { detachNodeFromParent, visitSkip } from '../lib/xast.js';
 import { collectStylesheet, computeStyle } from '../lib/style.js';
 
 /**
diff --git a/plugins/removeUselessStrokeAndFill.js b/plugins/removeUselessStrokeAndFill.js
index 09311865..ee4bc2b7 100644
--- a/plugins/removeUselessStrokeAndFill.js
+++ b/plugins/removeUselessStrokeAndFill.js
@@ -1,4 +1,4 @@
-import { visit, visitSkip, detachNodeFromParent } from '../lib/xast.js';
+import { detachNodeFromParent, visit, visitSkip } from '../lib/xast.js';
 import { collectStylesheet, computeStyle } from '../lib/style.js';
 import { hasScripts } from '../lib/svgo/tools.js';
 import { elemsGroups } from './_collections.js';
diff --git a/test/coa/_index.test.js b/test/coa/_index.test.js
index 40378047..a61cb30e 100644
--- a/test/coa/_index.test.js
+++ b/test/coa/_index.test.js
@@ -110,7 +110,7 @@ describe('coa', function () {
       tempFolder,
       '--quiet',
     ]);
-    let optimizedWeight = calcFolderSvgWeight(svgFolderPath);
+    const optimizedWeight = calcFolderSvgWeight(svgFolderPath);
     expect(optimizedWeight).toBeLessThanOrEqual(initWeight);
   });
 
diff --git a/test/svgo/_index.test.js b/test/svgo/_index.test.js
index 255b78d8..c7588c0f 100644
--- a/test/svgo/_index.test.js
+++ b/test/svgo/_index.test.js
@@ -2,7 +2,7 @@ import fs from 'node:fs/promises';
 import path from 'path';
 import { EOL } from 'os';
 import { fileURLToPath } from 'url';
-import { VERSION, optimize, builtinPlugins } from '../../lib/svgo.js';
+import { VERSION, builtinPlugins, optimize } from '../../lib/svgo.js';
 
 const __dirname = path.dirname(fileURLToPath(import.meta.url));
 
diff --git a/yarn.lock b/yarn.lock
index 5ab0049e..da1344e8 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -3952,12 +3952,12 @@ __metadata:
   languageName: node
   linkType: hard
 
-"prettier@npm:^3.2.5":
-  version: 3.2.5
-  resolution: "prettier@npm:3.2.5"
+"prettier@npm:^3.5.3":
+  version: 3.5.3
+  resolution: "prettier@npm:3.5.3"
   bin:
     prettier: bin/prettier.cjs
-  checksum: 2ee4e1417572372afb7a13bb446b34f20f1bf1747db77cf6ccaf57a9be005f2f15c40f903d41a6b79eec3f57fff14d32a20fb6dee1f126da48908926fe43c311
+  checksum: 61e97bb8e71a95d8f9c71f1fd5229c9aaa9d1e184dedb12399f76aa802fb6fdc8954ecac9df25a7f82ee7311cf8ddbd06baf5507388fc98e5b44036cc6a88a1b
   languageName: node
   linkType: hard
 
@@ -4546,7 +4546,7 @@ __metadata:
     pixelmatch: ^7.1.0
     playwright: ^1.51.1
     pngjs: ^7.0.0
-    prettier: ^3.2.5
+    prettier: ^3.5.3
     rimraf: ^5.0.7
     rollup: ^4.22.4
     sax: ^1.4.1