diff --git a/.gitignore b/.gitignore
index 34c6b93..3a90a94 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,3 +2,4 @@ node_modules
 dist
 yarn.lock
 package-lock.json
+nostr.js
diff --git a/README.md b/README.md
index 19cdfed..4733267 100644
--- a/README.md
+++ b/README.md
@@ -70,3 +70,20 @@ pool.addRelay('<url>')
 All functions expect bytearrays as hex strings and output bytearrays as hex strings.
 
 For other utils please read the source (for now).
+
+### Using from the browser (if you don't want to use a bundler)
+
+You can import nostr-tools as an ES module. Just add a script tag like this:
+
+```html
+<script type="module">
+  import {generatePrivateKey} from 'https://unpkg.com/nostr-tools/nostr.js'
+  console.log(generatePrivateKey())
+</script>
+```
+
+And import whatever function you would import from `"nostr-tools"` in a bundler.
+
+## License
+
+Public domain.
diff --git a/build.js b/build.js
new file mode 100755
index 0000000..d2f852d
--- /dev/null
+++ b/build.js
@@ -0,0 +1,25 @@
+#!/usr/bin/env node
+
+const esbuild = require('esbuild')
+const alias = require('esbuild-plugin-alias')
+const nodeGlobals = require('@esbuild-plugins/node-globals-polyfill').default
+
+const buildOptions = {
+  entryPoints: ['index.js'],
+  outfile: 'nostr.js',
+  bundle: true,
+  format: 'esm',
+  plugins: [
+    alias({
+      stream: require.resolve('readable-stream')
+    }),
+    nodeGlobals({buffer: true})
+  ],
+  define: {
+    window: 'self',
+    global: 'self'
+  },
+  loader: {'.js': 'jsx'}
+}
+
+esbuild.build(buildOptions).then(() => console.log('build success.'))
diff --git a/package.json b/package.json
index cafef9f..91a5321 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "nostr-tools",
-  "version": "0.23.0",
+  "version": "0.23.1",
   "description": "Tools for making a Nostr client.",
   "repository": {
     "type": "git",
@@ -30,7 +30,15 @@
     "client"
   ],
   "devDependencies": {
+    "@esbuild-plugins/node-globals-polyfill": "^0.1.1",
+    "esbuild": "^0.14.38",
+    "esbuild-plugin-alias": "^0.2.1",
     "eslint": "^8.5.0",
-    "eslint-plugin-babel": "^5.3.1"
+    "eslint-plugin-babel": "^5.3.1",
+    "events": "^3.3.0",
+    "readable-stream": "^3.6.0"
+  },
+  "scripts": {
+    "prepublish": "node build.js"
   }
 }