@c15t/browser: Cookie banner and cookie consent for any website, with one script tag

Cookie banner, preference center, and consent-gated scripts for sites without a build step: Webflow, WordPress, Framer, Squarespace, and plain HTML. Configure consent policies for GDPR and other privacy laws, then paste one script tag. Bundled apps can import the same runtime as an ES module.

c15t is used by 2,100+ sites, including expo.dev, zed.dev, unkey.dev, mintlify.com, and sazabi.com.

Key Features

• One script tag from a CDN, configured with data attributes or calls queued on window.c15t
• Prebuilt banner and preference dialog in a shadow root, so your site's CSS does not change them
• Vendor scripts use <script type="text/plain" data-c15t-category> and iframes use data-src and data-category. They load when the resolved policy allows their categories
• Buttons with data-c15t-action and links to #c15t-preferences work without code
• A headless build with the same runtime and window.c15t API, for your own banner
• DevTools (c15t.devtools.js) and IAB GPP (c15t.gpp.js) load as a second tag. For IAB TCF 2.4, load c15t.iab.js instead of c15t.js
• ES module entry points for bundled apps, which can use the @c15t/integrations vendor loaders

Prerequisites

• A page where you can add a <script> tag
• An Inth project (free sign-up). For development and tests, local mode needs no backend

Installation

Paste before </head>, with the backend URL from your Inth project:

<script
  src="https://cdn.jsdelivr.net/npm/@c15t/browser/dist/c15t.js"
  data-backend-url="YOUR_INTH_BACKEND_URL"
  defer
></script>

A URL without a version loads the newest release, so pin an exact version, such as @c15t/[email protected], in production. The default c15t.js requires a backend URL. Load dist/c15t.local.js for local mode or dist/c15t.headless.js for the runtime without any UI.

For bundled apps:

npm install @c15t/browser

Usage

1. Add the tag and reload. The banner appears when the visitor's policy asks for one
2. Change vendor tags to type="text/plain" with data-c15t-category="measurement" so they load when the resolved policy allows that category
3. Link to #c15t-preferences so visitors can reopen the preference dialog
4. For every attribute and method, see the HTML docs

window.c15t = window.c15t || [];
c15t.push(['on', 'consent', () => {
  if (c15t.has('measurement')) {
    startAnalytics();
  }
}]);

Run c15t on Inth

c15t needs a backend to serve policies and keep consent records. Inth runs it for you. It stores every choice with its region and policy version, audits your live site and pull requests for privacy risk, and on Pro and above keeps each region's consent rules current with managed policy packs. You don't run the consent database, geo lookups, uptime, or upgrades.

Sign-up is free. Run npx @inth/cli c15t to create a project and set up c15t, or create one by hand and copy its backend URL.

For development and tests, local mode keeps choices in the browser and keeps no consent records. Don't ship it to production. Its factory is local(). The old name, offline(), still works and goes away in v4.

Documentation

See the documentation for guides, API reference, and examples.

Which Script to Load

| File | Use it for | | --- | --- | | c15t.js | Production, with Inth. Set data-backend-url to your project's backend URL | | c15t.local.js | Local mode, for development and tests: choices stay in the browser, with local policy rules, and c15t keeps no server-side record of consent. Before 3.2.0 this file was c15t.offline.js | | c15t.headless.js | The runtime without UI, for your own banner. Can inline or fetch the backend's cacheable /manifest | | c15t.iab.js | IAB TCF 2.4. Configure iab with your registered CMP ID and vendor list. See the IAB example | | c15t.devtools.js | A DevTools panel, with a Location tab to try policies by region | | c15t.gpp.js | IAB GPP (__gpp) for US state opt-outs. Also available as mountGPP from @c15t/browser/gpp |

Docs for AI Agents

This package ships its documentation as Markdown, matched to the installed version. After you install it, point your coding agent at node_modules/@c15t/browser/AGENTS.md. It indexes every guide in node_modules/@c15t/browser/docs/.

On the web, every page of the c15t docs has a Markdown version, and llms.txt lists them all. Install the c15t agent skills with npx skills add c15t/skills.

Support

• Join our Discord community
• Open an issue on our GitHub repository
• Visit inth.com and use the chat widget
• Contact our support team via email [email protected]

Contributing

• Read the contribution guidelines before you open a pull request
• Follow the code of conduct

Security

Do not open a public issue for a security vulnerability. Report it privately through GitHub's vulnerability reporting. We examine every valid report.

• Do not share the vulnerability in public forums, issues, or pull requests
• Give the steps to reproduce it and the versions it affects
• Give us time to release a fix before you disclose it

License

Apache License 2.0

Built by Inth