diff --git a/.gitignore b/.gitignore
index c2658d7..dd3d82b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
 node_modules/
+yarn-error.log
diff --git a/.npmignore b/.npmignore
index 6ca4202..921f1c9 100644
--- a/.npmignore
+++ b/.npmignore
@@ -1,2 +1,3 @@
 test.*
 suite.*
+bench/
diff --git a/bench/.gitignore b/bench/.gitignore
new file mode 100644
index 0000000..2211df6
--- /dev/null
+++ b/bench/.gitignore
@@ -0,0 +1 @@
+*.txt
diff --git a/bench/README.md b/bench/README.md
new file mode 100644
index 0000000..957b9cb
--- /dev/null
+++ b/bench/README.md
@@ -0,0 +1,69 @@
+Benchmark code.
+Usage:
+
+```bash
+./compare.js <filename>
+# or
+./compare.js <length>
+```
+
+If you don't provide a source file, or specify a length instead, this will generate actual random text in JavaScript.
+
+For a better test, use suggested UTF-8 encoded source text from [Project Gutenberg](https://www.gutenberg.org/files/23841/23841-0.txt).
+This has a ratio of "bytes-to-length" of 0.35; the lower the ratio, the better the test (ASCII has a ratio of 1).
+
+This is an odd number, but we're comparing the on-disk UTF-8 bytes (which optimize for ASCII and other low Unicode values) to the length of JavaScript's UCS-2 / UTF-16 internal representation.
+All Unicode code points can be represented as either one or two "lengths" of a JavaScript string, but each code point can be between 1-4 bytes in UTF-8.
+The possible ratios therefore range from 0.25 through 1.0.
+
+# Results
+
+For the suggested text on my test rig (macOS 3.6GHz i9), output looks like (snipped):
+
+```
+compare (file): length=971478, bytes=2740678 (ratio=0.35)
+
+  10.2209ms .native 971477
+  10.8853ms .native 971477
+  10.9297ms .native 971477
+  11.1351ms .native 971477
+  11.3154ms .native 971477
+  11.3741ms .native 971477
+  11.4921ms .native 971477
+  12.1611ms .native 971477
+  25.9949ms fast-text-encoding 
+  26.3912ms fast-text-encoding 
+  26.7037ms fast-text-encoding 
+  32.1910ms fast-text-encoding 
+  36.6454ms fast-text-encoding 
+  44.6358ms fast-text-encoding 
+  47.1846ms fast-text-encoding 
+  51.7178ms fast-text-encoding 
+ 125.2835ms fastestsmallesttextencoderdecoder 
+ 126.0772ms fastestsmallesttextencoderdecoder 
+ 129.5148ms fastestsmallesttextencoderdecoder 
+ 129.9449ms fastestsmallesttextencoderdecoder 
+ 135.1421ms fastestsmallesttextencoderdecoder 
+ 137.6716ms fastestsmallesttextencoderdecoder 
+ 152.4639ms fastestsmallesttextencoderdecoder 
+ 155.1741ms fastestsmallesttextencoderdecoder 
+ 467.4895ms text-encoding-polyfill 971477
+ 469.5857ms text-encoding-polyfill 971477
+ 470.4829ms text-encoding-polyfill 971477
+ 472.6093ms text-encoding-polyfill 971477
+ 472.6358ms text-encoding-polyfill 971477
+ 474.5790ms text-encoding-polyfill 971477
+ 476.7881ms text-encoding-polyfill 971477
+ 477.0778ms text-encoding 971477
+ 478.0450ms text-encoding-polyfill 971477
+ 478.2031ms text-encoding 971477
+ 480.0009ms text-encoding 971477
+ 480.2125ms text-encoding 971477
+ 485.2014ms text-encoding 971477
+ 485.9727ms text-encoding 971477
+ 486.2783ms text-encoding 971477
+ 490.5393ms text-encoding 971477
+```
+
+As you'd expect, the native implementation is the speediest.
+There's a bit of noise in the test; it's not perfect.
diff --git a/bench/compare.js b/bench/compare.js
new file mode 100755
index 0000000..5d90b33
--- /dev/null
+++ b/bench/compare.js
@@ -0,0 +1,111 @@
+#!/usr/bin/env node --max-old-space-size=8192
+
+const {performance} = require('perf_hooks');
+const chalk = require('chalk');
+const fs = require('fs');
+
+const packages = ['fast-text-encoding', 'text-encoding', 'text-encoding-polyfill', 'text-encoding-utf-8', 'fastestsmallesttextencoderdecoder'];
+const runs = 8;
+
+function buildRandomString(length) {
+  const parts = [];
+  for (let i = 0; i < length; ++i) {
+    const v = 1.0 - Math.pow(Math.random(), 0.25);  // bias towards start
+    parts.push(Math.floor(v * 0x10FFFF));
+  }
+  return String.fromCodePoint(...parts);
+}
+
+let string;
+
+if (+process.argv[2] || process.argv.length < 3) {
+  // possibly a number
+  string = buildRandomString(+process.argv[2] || (256 * 256));
+  console.info(`compare (random): length=${chalk.yellow(string.length)}`);
+} else {
+  const stat = fs.statSync(process.argv[2]);
+  string = fs.readFileSync(process.argv[2], 'utf-8');
+  const ratio = (string.length / stat.size);
+  console.info(`compare (file): length=${chalk.yellow(string.length)}, bytes=${chalk.yellow(stat.size)} (ratio=${chalk.yellow(ratio.toFixed(2))})`);
+}
+
+// remove 'text-encoding-utf-8' after a certain size as it's just pathologically bad
+if (string.length >= 32768) {
+  const index = packages.indexOf('text-encoding-utf-8');
+  packages.splice(index, 1);
+}
+
+console.info('');
+
+function run(use, s) {
+  const te = new use.TextEncoder('utf-8');
+  const data = te.encode(s);
+
+  const td = new use.TextDecoder('utf-8');
+  const outs = td.decode(data);
+
+  return outs.length;
+}
+
+function shuffle(arr) {
+  const out = [];
+  while (arr.length) {
+    const choice = Math.floor(Math.random() * arr.length);
+    out.push(arr.splice(choice, 1)[0]);
+  }
+  arr.push(...out);
+}
+
+const results = [];
+const impl = {};
+const hasNative = (global.TextEncoder && global.TextDecoder)
+const nativeImpl = hasNative ? {TextEncoder: global.TextEncoder, TextDecoder: global.TextDecoder} : null;
+
+for (const name of packages) {
+  delete global.TextDecoder;
+  delete global.TextEncoder;
+  const exports = require(name);
+  const use = {TextEncoder: global.TextEncoder, TextDecoder: global.TextDecoder, ...exports};
+
+  if (hasNative && ((use.TextDecoder === nativeImpl.TextDecoder || use.TextEncoder === nativeImpl.TextEncoder))) {
+    throw new Error(`package ${name} used native code`);
+  }
+
+  impl[name] = use;
+}
+
+if (hasNative) {
+  packages.push('.native');
+  impl['.native'] = nativeImpl;
+}
+
+(async function() {
+
+  for (let i = 0; i < runs; ++i) {
+    shuffle(packages);
+    console.info('run', (i + 1));
+  
+    for (const name of packages) {
+      delete global.TextDecoder;
+      delete global.TextEncoder;
+  
+      console.debug(chalk.gray(name));
+      const use = impl[name];
+  
+      const start = performance.now();
+      const length = run(use, string);
+      const duration = performance.now() - start;
+      results.push({name, duration, length});
+
+      // take a breather
+      await new Promise((r) => setTimeout(r, 100));
+    }
+  }
+
+  results.sort(({duration: a}, {duration: b}) => a - b);
+
+  for (const {name, duration, length} of results) {
+    console.info((duration.toFixed(4) + 'ms').padStart(11), chalk.green(name), length !== string.length ? chalk.red(length) : '');
+  }
+
+})();
diff --git a/bench/package.json b/bench/package.json
new file mode 100644
index 0000000..71d199e
--- /dev/null
+++ b/bench/package.json
@@ -0,0 +1,10 @@
+{
+  "dependencies": {
+    "chalk": "^4.0.0",
+    "fast-text-encoding": "^1.0.2",
+    "fastestsmallesttextencoderdecoder": "^1.0.21",
+    "text-encoding": "^0.7.0",
+    "text-encoding-polyfill": "^0.6.7",
+    "text-encoding-utf-8": "^1.0.2"
+  }
+}
diff --git a/bench/yarn.lock b/bench/yarn.lock
new file mode 100644
index 0000000..ee3d086
--- /dev/null
+++ b/bench/yarn.lock
@@ -0,0 +1,73 @@
+# THIS IS AN AUTOGENERATED FILE. DO NOT EDIT THIS FILE DIRECTLY.
+# yarn lockfile v1
+
+
+"@types/color-name@^1.1.1":
+  version "1.1.1"
+  resolved "https://registry.yarnpkg.com/@types/color-name/-/color-name-1.1.1.tgz#1c1261bbeaa10a8055bbc5d8ab84b7b2afc846a0"
+  integrity sha512-rr+OQyAjxze7GgWrSaJwydHStIhHq2lvY3BOC2Mj7KnzI7XK0Uw1TOOdI9lDoajEbSWLiYgoo4f1R51erQfhPQ==
+
+ansi-styles@^4.1.0:
+  version "4.2.1"
+  resolved "https://registry.yarnpkg.com/ansi-styles/-/ansi-styles-4.2.1.tgz#90ae75c424d008d2624c5bf29ead3177ebfcf359"
+  integrity sha512-9VGjrMsG1vePxcSweQsN20KY/c4zN0h9fLjqAbwbPfahM3t+NL+M9HC8xeXG2I8pX5NoamTGNuomEUFI7fcUjA==
+  dependencies:
+    "@types/color-name" "^1.1.1"
+    color-convert "^2.0.1"
+
+chalk@^4.0.0:
+  version "4.0.0"
+  resolved "https://registry.yarnpkg.com/chalk/-/chalk-4.0.0.tgz#6e98081ed2d17faab615eb52ac66ec1fe6209e72"
+  integrity sha512-N9oWFcegS0sFr9oh1oz2d7Npos6vNoWW9HvtCg5N1KRFpUhaAhvTv5Y58g880fZaEYSNm3qDz8SU1UrGvp+n7A==
+  dependencies:
+    ansi-styles "^4.1.0"
+    supports-color "^7.1.0"
+
+color-convert@^2.0.1:
+  version "2.0.1"
+  resolved "https://registry.yarnpkg.com/color-convert/-/color-convert-2.0.1.tgz#72d3a68d598c9bdb3af2ad1e84f21d896abd4de3"
+  integrity sha512-RRECPsj7iu/xb5oKYcsFHSppFNnsj/52OVTRKb4zP5onXwVF3zVmmToNcOfGC+CRDpfK/U584fMg38ZHCaElKQ==
+  dependencies:
+    color-name "~1.1.4"
+
+color-name@~1.1.4:
+  version "1.1.4"
+  resolved "https://registry.yarnpkg.com/color-name/-/color-name-1.1.4.tgz#c2a09a87acbde69543de6f63fa3995c826c536a2"
+  integrity sha512-dOy+3AuW3a2wNbZHIuMZpTcgjGuLU/uBL/ubcZF9OXbDo8ff4O8yVp5Bf0efS8uEoYo5q4Fx7dY9OgQGXgAsQA==
+
+fast-text-encoding@^1.0.2:
+  version "1.0.2"
+  resolved "https://registry.yarnpkg.com/fast-text-encoding/-/fast-text-encoding-1.0.2.tgz#ff1ad5677bde049e0f8656aa6083a7ef2c5836e2"
+  integrity sha512-5rQdinSsycpzvAoHga2EDn+LRX1d5xLFsuNG0Kg61JrAT/tASXcLL0nf/33v+sAxlQcfYmWbTURa1mmAf55jGw==
+
+fastestsmallesttextencoderdecoder@^1.0.21:
+  version "1.0.21"
+  resolved "https://registry.yarnpkg.com/fastestsmallesttextencoderdecoder/-/fastestsmallesttextencoderdecoder-1.0.21.tgz#b67599f879417229bad311c9e1f2918dfd155c63"
+  integrity sha512-43gkbs+ruBXej0jhqcOKZ/DfKJmdWXrHZ5ZeHfYdnJ53aqU+p4JfhZrcNHBLNswieV7DOlj6f4q/+Fw9YMy/5Q==
+
+has-flag@^4.0.0:
+  version "4.0.0"
+  resolved "https://registry.yarnpkg.com/has-flag/-/has-flag-4.0.0.tgz#944771fd9c81c81265c4d6941860da06bb59479b"
+  integrity sha512-EykJT/Q1KjTWctppgIAgfSO0tKVuZUjhgMr17kqTumMl6Afv3EISleU7qZUzoXDFTAHTDC4NOoG/ZxU3EvlMPQ==
+
+supports-color@^7.1.0:
+  version "7.1.0"
+  resolved "https://registry.yarnpkg.com/supports-color/-/supports-color-7.1.0.tgz#68e32591df73e25ad1c4b49108a2ec507962bfd1"
+  integrity sha512-oRSIpR8pxT1Wr2FquTNnGet79b3BWljqOuoW/h4oBhxJ/HUbX5nX6JSruTkvXDCFMwDPvsaTTbvMLKZWSy0R5g==
+  dependencies:
+    has-flag "^4.0.0"
+
+text-encoding-polyfill@^0.6.7:
+  version "0.6.7"
+  resolved "https://registry.yarnpkg.com/text-encoding-polyfill/-/text-encoding-polyfill-0.6.7.tgz#4d27de0153e4c86eb2631ffd74c2f3f57969a9ec"
+  integrity sha512-/DZ1XJqhbqRkCop6s9ZFu8JrFRwmVuHg4quIRm+ziFkR3N3ec6ck6yBvJ1GYeEQZhLVwRW0rZE+C3SSJpy0RTg==
+
+text-encoding-utf-8@^1.0.2:
+  version "1.0.2"
+  resolved "https://registry.yarnpkg.com/text-encoding-utf-8/-/text-encoding-utf-8-1.0.2.tgz#585b62197b0ae437e3c7b5d0af27ac1021e10d13"
+  integrity sha512-8bw4MY9WjdsD2aMtO0OzOCY3pXGYNx2d2FfHRVUKkiCPDWjKuOlhLVASS+pD7VkLTVjW268LYJHwsnPFlBpbAg==
+
+text-encoding@^0.7.0:
+  version "0.7.0"
+  resolved "https://registry.yarnpkg.com/text-encoding/-/text-encoding-0.7.0.tgz#f895e836e45990624086601798ea98e8f36ee643"
+  integrity sha512-oJQ3f1hrOnbRLOcwKz0Liq2IcrvDeZRHXhd9RgLrsT+DjWY/nty1Hi7v3dtkaEYbPYe0mUoOfzRrMwfXXwgPUA==