Build and Side Load in Chrome

May 26, 2026 ยท View on GitHub

Use this tutorial to build Lens and load it as an unpacked Chrome extension.

Prerequisites

  • Node.js 20 or later
  • Yarn
  • Google Chrome

1. Install dependencies

From the repository root:

cd Source
yarn

2. Build the extension

Build the production bundle:

yarn build

This creates Source/dist/, including the generated manifest.json and bundled assets.

3. Open the Chrome extensions page

  1. Open chrome://extensions.
  2. Enable Developer mode.

4. Side load the extension

  1. Select Load unpacked.
  2. Choose the Source/dist folder.

Chrome loads Lens - Cratis Developer Tools as an unpacked extension.

5. Reload after changes

If you change source files, rebuild and reload:

yarn build

Then use the Reload action for Lens on chrome://extensions.

For faster iteration during development, use Local Development with watch mode.