diff --git a/benchmarks/diff_multi_bench_output.js b/benchmarks/diff_multi_bench_output.js
new file mode 100755
index 0000000000..7432d14407
--- /dev/null
+++ b/benchmarks/diff_multi_bench_output.js
@@ -0,0 +1,91 @@
+'use strict'
+
+// `node diffMultiBenchOutput.js beforeBench.txt afterBench.txt`
+
+var fs = require('fs')
+var file1 = process.argv[2]
+var file2 = process.argv[3]
+
+if (!file1 || !file2) {
+  console.log('Please supply two file arguments:')
+  var n = __filename
+  n = n.substring(n.lastIndexOf('/', n.length))
+  console.log('    node .' + n + ' benchBefore.txt benchAfter.txt\n')
+  console.log('To generate the benchmark files, run')
+  console.log('    npm run benchmark > benchBefore.txt\n')
+  console.log('Thank you for benchmarking responsibly.')
+  process.exit(1)
+}
+
+var beforeLines = fs.readFileSync(file1, 'utf8').split('\n')
+var afterLines = fs.readFileSync(file2, 'utf8').split('\n')
+
+console.log('Comparing before,', file1, '(', beforeLines.length, 'lines)', 'to after,', file2, '(', afterLines.length, 'lines)')
+
+function isWhitespace (s) {
+  return !!s.trim()
+}
+
+function pad (input, len, chr, right) {
+  var str = input.toString()
+  chr = chr || ' '
+
+  if (right) {
+    while (str.length < len) {
+      str += chr
+    }
+  } else {
+    while (str.length < len) {
+      str = chr + str
+    }
+  }
+  return str
+}
+
+// green if greater than 0, red otherwise
+function humanizeDiff (num, unit, toFixed) {
+  unit = unit || ''
+  if (num > 0) {
+    return ' +' + pad(num.toFixed(toFixed || 0) + unit, 7)
+  }
+  return ' -' + pad(Math.abs(num).toFixed(toFixed || 0) + unit, 7)
+}
+
+function commandName (words) {
+  var line = words.join(' ')
+  return line.substr(0, line.indexOf(','))
+}
+
+beforeLines.forEach(function (b, i) {
+  var a = afterLines[i]
+  if (!a || !b || !b.trim() || !a.trim()) {
+    // console.log('#ignored#', '>'+a+'<', '>'+b+'<');
+    return
+  }
+  var bWords = b.split(' ').filter(isWhitespace)
+  var aWords = a.split(' ').filter(isWhitespace)
+
+  var ops = [bWords, aWords].map(function (words) {
+    // console.log(words);
+    return words.slice(-2, -1) | 0
+  }).filter(function (num) {
+    var isNaN = !num && num !== 0
+    return !isNaN
+  })
+  if (ops.length !== 2) {
+    return
+  }
+  var delta = ops[1] - ops[0]
+  var pct = +((delta / ops[0]) * 100)
+  ops[0] = pad(ops[0], 6)
+  ops[1] = pad(ops[1], 6)
+  delta = humanizeDiff(delta)
+  var smallDelta = pct < 3 && pct > -3
+  // Let's mark differences above 20% bold
+  var bigDelta = pct > 20 || pct < -20 ? ';1' : ''
+  pct = humanizeDiff(pct, '', 2) + '%'
+  var str = pad((commandName(aWords) === commandName(bWords) ? commandName(aWords) + ':' : '404:'), 14, false, true) +
+        (pad(ops.join(' -> '), 15) + ' ops/sec (∆' + delta + pct + ')')
+  str = (smallDelta ? '' : (/-[^>]/.test(str) ? '\x1b[31' : '\x1b[32') + bigDelta + 'm') + str + '\x1b[0m'
+  console.log(str)
+})