diff --git a/lib/svgo/jsAPI.js b/lib/svgo/jsAPI.js
index acceb7e3..1894964b 100644
--- a/lib/svgo/jsAPI.js
+++ b/lib/svgo/jsAPI.js
@@ -296,7 +296,7 @@ JSAPI.prototype.computedAttr = function (name, val) {
   if (val != null) {
     return elem ? elem.hasAttr(name, val) : false;
   } else if (elem && elem.hasAttr(name)) {
-    return elem.attrs[name].value;
+    return elem.attributes[name];
   }
 };
 
diff --git a/plugins/_applyTransforms.js b/plugins/_applyTransforms.js
index 63dbc056..307160da 100644
--- a/plugins/_applyTransforms.js
+++ b/plugins/_applyTransforms.js
@@ -58,9 +58,11 @@ const applyTransforms = (elem, pathData, params) => {
       let hasStrokeWidth = false;
 
       do {
-        if (idElem.hasAttr('stroke-width')) hasStrokeWidth = true;
+        if (idElem.attributes['stroke-width']) {
+          hasStrokeWidth = true;
+        }
       } while (
-        !idElem.hasAttr('id', id) &&
+        idElem.attributes.id !== id &&
         !hasStrokeWidth &&
         (idElem = idElem.parentNode)
       );
diff --git a/plugins/collapseGroups.js b/plugins/collapseGroups.js
index d75c5615..dfd602c7 100644
--- a/plugins/collapseGroups.js
+++ b/plugins/collapseGroups.js
@@ -1,22 +1,23 @@
 'use strict';
 
+const { inheritableAttrs, elemsGroups } = require('./_collections');
+
 exports.type = 'perItemReverse';
 
 exports.active = true;
 
 exports.description = 'collapses useless groups';
 
-var collections = require('./_collections'),
-  attrsInheritable = collections.inheritableAttrs,
-  animationElems = collections.elemsGroups.animation;
-
-function hasAnimatedAttr(item) {
-  return (
-    (item.isElem(animationElems) && item.hasAttr('attributeName', this)) ||
-    (item.type === 'element' &&
-      item.children.length !== 0 &&
-      item.children.some(hasAnimatedAttr, this))
-  );
+function hasAnimatedAttr(item, name) {
+  if (item.type === 'element') {
+    return (
+      (elemsGroups.animation.includes(item.name) &&
+        item.attributes.attributeName === name) ||
+      (item.children.length !== 0 &&
+        item.children.some((child) => hasAnimatedAttr(child, name)))
+    );
+  }
+  return false;
 }
 
 /*
@@ -51,33 +52,35 @@ exports.fn = function (item) {
   ) {
     item.children.forEach(function (g, i) {
       // non-empty groups
-      if (g.isElem('g') && g.children.length !== 0) {
+      if (g.type === 'element' && g.name === 'g' && g.children.length !== 0) {
         // move group attibutes to the single child element
-        if (g.hasAttr() && g.children.length === 1) {
+        if (Object.keys(g.attributes).length !== 0 && g.children.length === 1) {
           var inner = g.children[0];
 
           if (
             inner.type === 'element' &&
-            !inner.hasAttr('id') &&
-            !g.hasAttr('filter') &&
-            !(g.hasAttr('class') && inner.hasAttr('class')) &&
-            ((!g.hasAttr('clip-path') && !g.hasAttr('mask')) ||
-              (inner.isElem('g') &&
-                !g.hasAttr('transform') &&
-                !inner.hasAttr('transform')))
+            inner.attributes.id == null &&
+            g.attributes.filter == null &&
+            (g.attributes.class == null || inner.attributes.class == null) &&
+            ((g.attributes['clip-path'] == null && g.attributes.mask == null) ||
+              (inner.type === 'element' &&
+                inner.name === 'g' &&
+                g.attributes.transform == null &&
+                inner.attributes.transform == null))
           ) {
             for (const [name, value] of Object.entries(g.attributes)) {
-              if (g.children.some(hasAnimatedAttr, name)) return;
+              if (g.children.some((item) => hasAnimatedAttr(item, name)))
+                return;
 
-              if (!inner.hasAttr(name)) {
+              if (inner.attributes[name] == null) {
                 inner.attributes[name] = value;
               } else if (name == 'transform') {
                 inner.attributes[name] = value + ' ' + inner.attributes[name];
-              } else if (inner.hasAttr(name, 'inherit')) {
+              } else if (inner.attributes[name] === 'inherit') {
                 inner.attributes[name] = value;
               } else if (
-                attrsInheritable.includes(name) === false &&
-                !inner.hasAttr(name, value)
+                inheritableAttrs.includes(name) === false &&
+                inner.attributes[name] !== value
               ) {
                 return;
               }
@@ -89,10 +92,8 @@ exports.fn = function (item) {
 
         // collapse groups without attributes
         if (
-          !g.hasAttr() &&
-          !g.children.some(function (item) {
-            return item.isElem(animationElems);
-          })
+          Object.keys(g.attributes).length === 0 &&
+          !g.children.some((item) => item.isElem(elemsGroups.animation))
         ) {
           item.spliceContent(i, 1, g.children);
         }
diff --git a/plugins/convertPathData.js b/plugins/convertPathData.js
index 780bdd28..3b5ef63c 100644
--- a/plugins/convertPathData.js
+++ b/plugins/convertPathData.js
@@ -57,7 +57,11 @@ let arcTolerance;
  * @author Kir Belevich
  */
 exports.fn = function (item, params) {
-  if (item.isElem(pathElems) && item.hasAttr('d')) {
+  if (
+    item.type === 'element' &&
+    pathElems.includes(item.name) &&
+    item.attributes.d != null
+  ) {
     const computedStyle = computeStyle(item);
     precision = params.floatPrecision;
     error =
diff --git a/plugins/convertTransform.js b/plugins/convertTransform.js
index ac346d04..aa33e964 100644
--- a/plugins/convertTransform.js
+++ b/plugins/convertTransform.js
@@ -46,17 +46,17 @@ var cleanupOutData = require('../lib/svgo/tools').cleanupOutData,
 exports.fn = function (item, params) {
   if (item.type === 'element') {
     // transform
-    if (item.hasAttr('transform')) {
+    if (item.attributes.transform != null) {
       convertTransform(item, 'transform', params);
     }
 
     // gradientTransform
-    if (item.hasAttr('gradientTransform')) {
+    if (item.attributes.gradientTransform != null) {
       convertTransform(item, 'gradientTransform', params);
     }
 
     // patternTransform
-    if (item.hasAttr('patternTransform')) {
+    if (item.attributes.patternTransform != null) {
       convertTransform(item, 'patternTransform', params);
     }
   }
diff --git a/plugins/moveElemsAttrsToGroup.js b/plugins/moveElemsAttrsToGroup.js
index cd8210e3..a2a0c420 100644
--- a/plugins/moveElemsAttrsToGroup.js
+++ b/plugins/moveElemsAttrsToGroup.js
@@ -1,14 +1,13 @@
 'use strict';
 
+const { inheritableAttrs, pathElems } = require('./_collections');
+
 exports.type = 'perItemReverse';
 
 exports.active = true;
 
 exports.description = 'moves elements attributes to the existing group wrapper';
 
-var inheritableAttrs = require('./_collections').inheritableAttrs,
-  pathElems = require('./_collections.js').pathElems;
-
 /**
  * Collapse content's intersected and inheritable
  * attributes to the existing group wrapper.
@@ -34,14 +33,22 @@ var inheritableAttrs = require('./_collections').inheritableAttrs,
  * @author Kir Belevich
  */
 exports.fn = function (item) {
-  if (item.isElem('g') && item.children.length > 1) {
+  if (
+    item.type === 'element' &&
+    item.name === 'g' &&
+    item.children.length > 1
+  ) {
     var intersection = {},
       hasTransform = false,
-      hasClip = item.hasAttr('clip-path') || item.hasAttr('mask'),
+      hasClip =
+        item.attributes['clip-path'] != null || item.attributes.mask != null,
       intersected = item.children.every(function (inner) {
-        if (inner.type === 'element' && inner.hasAttr()) {
+        if (
+          inner.type === 'element' &&
+          Object.keys(inner.attributes).length !== 0
+        ) {
           // don't mess with possible styles (hack until CSS parsing is implemented)
-          if (inner.hasAttr('class')) return false;
+          if (inner.attributes.class) return false;
           if (!Object.keys(intersection).length) {
             intersection = inner.attributes;
           } else {
@@ -68,7 +75,7 @@ exports.fn = function (item) {
 
             if (name === 'transform') {
               if (!hasTransform) {
-                if (item.hasAttr('transform')) {
+                if (item.attributes.transform != null) {
                   item.attributes.transform =
                     item.attributes.transform + ' ' + value;
                 } else {
diff --git a/plugins/moveGroupAttrsToElems.js b/plugins/moveGroupAttrsToElems.js
index ce6f1983..4d798f55 100644
--- a/plugins/moveGroupAttrsToElems.js
+++ b/plugins/moveGroupAttrsToElems.js
@@ -1,14 +1,14 @@
 'use strict';
 
+const { pathElems, referencesProps } = require('./_collections.js');
+
 exports.type = 'perItem';
 
 exports.active = true;
 
 exports.description = 'moves some group attributes to the content elements';
 
-var collections = require('./_collections.js'),
-  pathElems = collections.pathElems.concat(['g', 'text']),
-  referencesProps = collections.referencesProps;
+const pathElemsWithGroupsAndText = [...pathElems, 'g', 'text'];
 
 /**
  * Move group attrs to the content elements.
@@ -41,7 +41,9 @@ exports.fn = function (item) {
         referencesProps.includes(name) && value.includes('url(')
     ) === false &&
     item.children.every(
-      (inner) => inner.isElem(pathElems) && !inner.hasAttr('id')
+      (inner) =>
+        pathElemsWithGroupsAndText.includes(inner.name) &&
+        inner.attributes.id == null
     )
   ) {
     for (const inner of item.children) {
diff --git a/plugins/removeEmptyContainers.js b/plugins/removeEmptyContainers.js
index 4648f71a..230a1266 100644
--- a/plugins/removeEmptyContainers.js
+++ b/plugins/removeEmptyContainers.js
@@ -1,13 +1,13 @@
 'use strict';
 
+const { elemsGroups } = require('./_collections');
+
 exports.type = 'perItemReverse';
 
 exports.active = true;
 
 exports.description = 'removes empty container elements';
 
-var container = require('./_collections').elemsGroups.container;
-
 /**
  * Remove empty containers.
  *
@@ -25,16 +25,19 @@ var container = require('./_collections').elemsGroups.container;
  * @author Kir Belevich
  */
 exports.fn = function (item) {
-  return (
-    item.isElem(container) === false ||
-    (item.type === 'element' && item.children.length !== 0) ||
-    item.isElem('svg') ||
-    // empty patterns may contain reusable configuration
-    (item.isElem('pattern') && Object.keys(item.attributes).length !== 0) ||
-    // The 'g' may not have content, but the filter may cause a rectangle
-    // to be created and filled with pattern.
-    (item.isElem('g') && item.hasAttr('filter')) ||
-    // empty <mask> hides masked element
-    (item.isElem('mask') && item.hasAttr('id'))
-  );
+  if (item.type === 'element') {
+    return (
+      item.children.length !== 0 ||
+      elemsGroups.container.includes(item.name) === false ||
+      item.name === 'svg' ||
+      // empty patterns may contain reusable configuration
+      (item.name === 'pattern' && Object.keys(item.attributes).length !== 0) ||
+      // The 'g' may not have content, but the filter may cause a rectangle
+      // to be created and filled with pattern.
+      (item.name === 'g' && item.attributes.filter != null) ||
+      // empty <mask> hides masked element
+      (item.name === 'mask' && item.attributes.id != null)
+    );
+  }
+  return true;
 };
diff --git a/plugins/removeEmptyText.js b/plugins/removeEmptyText.js
index 89b4644c..30d3e7c2 100644
--- a/plugins/removeEmptyText.js
+++ b/plugins/removeEmptyText.js
@@ -34,18 +34,24 @@ exports.params = {
  * @author Kir Belevich
  */
 exports.fn = function (item, params) {
-  // Remove empty text element
-  if (params.text && item.isElem('text') && item.children.length === 0) {
-    return false;
-  }
+  if (item.type === 'element') {
+    // Remove empty text element
+    if (params.text && item.name === 'text' && item.children.length === 0) {
+      return false;
+    }
 
-  // Remove empty tspan element
-  if (params.tspan && item.isElem('tspan') && item.children.length === 0) {
-    return false;
-  }
+    // Remove empty tspan element
+    if (params.tspan && item.name === 'tspan' && item.children.length === 0) {
+      return false;
+    }
 
-  // Remove tref with empty xlink:href attribute
-  if (params.tref && item.isElem('tref') && !item.hasAttrLocal('href')) {
-    return false;
+    // Remove tref with empty xlink:href attribute
+    if (
+      params.tref &&
+      item.name === 'tref' &&
+      item.attributes['xlink:href'] == null
+    ) {
+      return false;
+    }
   }
 };
diff --git a/plugins/removeOffCanvasPaths.js b/plugins/removeOffCanvasPaths.js
index d7743bc7..be363adc 100644
--- a/plugins/removeOffCanvasPaths.js
+++ b/plugins/removeOffCanvasPaths.js
@@ -25,7 +25,8 @@ var _path = require('./_path.js'),
  */
 exports.fn = function (item) {
   if (
-    item.isElem('path') &&
+    item.type === 'element' &&
+    item.name === 'path' &&
     item.attributes.d != null &&
     typeof viewBox !== 'undefined'
   ) {
@@ -44,7 +45,7 @@ exports.fn = function (item) {
 
     return intersects(viewBoxJS, pathJS);
   }
-  if (item.isElem('svg')) {
+  if (item.type === 'element' && item.name === 'svg') {
     parseViewBox(item);
   }
 
@@ -59,8 +60,10 @@ exports.fn = function (item) {
  */
 function hasTransform(item) {
   return (
-    item.hasAttr('transform') ||
-    (item.parentNode && hasTransform(item.parentNode))
+    item.attributes.transform != null ||
+    (item.parentNode &&
+      item.parentNode.type === 'element' &&
+      hasTransform(item.parentNode))
   );
 }
 
diff --git a/plugins/removeRasterImages.js b/plugins/removeRasterImages.js
index 38c18c66..ec87f8bd 100644
--- a/plugins/removeRasterImages.js
+++ b/plugins/removeRasterImages.js
@@ -18,8 +18,10 @@ exports.description = 'removes raster images (disabled by default)';
  */
 exports.fn = function (item) {
   if (
-    item.isElem('image') &&
-    item.hasAttrLocal('href', /(\.|image\/)(jpg|png|gif)/)
+    item.type === 'element' &&
+    item.name === 'image' &&
+    item.attributes['xlink:href'] != null &&
+    /(\.|image\/)(jpg|png|gif)/.test(item.attributes['xlink:href'])
   ) {
     return false;
   }
diff --git a/plugins/removeUselessDefs.js b/plugins/removeUselessDefs.js
index 70516364..4beb627f 100644
--- a/plugins/removeUselessDefs.js
+++ b/plugins/removeUselessDefs.js
@@ -1,13 +1,13 @@
 'use strict';
 
+const { elemsGroups } = require('./_collections');
+
 exports.type = 'perItem';
 
 exports.active = true;
 
 exports.description = 'removes elements in <defs> without id';
 
-var nonRendering = require('./_collections').elemsGroups.nonRendering;
-
 /**
  * Removes content of defs and properties that aren't rendered directly without ids.
  *
@@ -17,20 +17,25 @@ var nonRendering = require('./_collections').elemsGroups.nonRendering;
  * @author Lev Solntsev
  */
 exports.fn = function (item) {
-  if (item.isElem('defs')) {
-    item.children = getUsefulItems(item, []);
-    if (item.children.length === 0) {
+  if (item.type === 'element') {
+    if (item.name === 'defs') {
+      item.children = getUsefulItems(item, []);
+      if (item.children.length === 0) {
+        return false;
+      }
+    } else if (
+      elemsGroups.nonRendering.includes(item.name) &&
+      item.attributes.id == null
+    ) {
       return false;
     }
-  } else if (item.isElem(nonRendering) && !item.hasAttr('id')) {
-    return false;
   }
 };
 
 function getUsefulItems(item, usefulItems) {
   for (const child of item.children) {
     if (child.type === 'element') {
-      if (child.hasAttr('id') || child.isElem('style')) {
+      if (child.attributes.id != null || child.name === 'style') {
         usefulItems.push(child);
         child.parentNode = item;
       } else {