Clear on revocation

Configure cleanup

Gating stops new requests, but it leaves the cookies and storage keys a vendor already wrote. List the ones each optional category owns in the script tag's config. When that category is denied, c15t deletes them:

<script>
  window.c15t = window.c15t || [];
  c15t.push(['config', {
    clearOnRevocation: {
      measurement: { cookies: ['_ga', '_ga_*'], localStorage: ['analytics:*'] },
      marketing: { cookies: ['_fbp'], sessionStorage: ['campaign-id'] },
    },
  }]);
</script>

Put this before the c15t script tag. c15t reads the config once, at start.

Name cookies and keys

Each optional category takes three lists. Without clearOnRevocation, c15t deletes nothing, and necessary cannot be configured.

Use an exact name, or a prefix followed by *. _ga_* matches _ga_ABC123 but not _ga, so list both. Regular expressions, a * anywhere but the end, and a bare * are not supported. Cookie names are matched as written, without URL decoding.

By default c15t tries the current host and its parent domains, and the current path and its parents. For a cookie set on a specific scope, use an object:

const cookies = [
  { name: 'analytics-id', domain: 'example.com', path: '/' },
  { name: 'checkout-metrics', domain: '', path: '/checkout' },
  { name: 'partitioned-metrics', partitioned: true },
];

An empty domain means a host-only cookie. A domain or path you set replaces the automatic attempts for that field. Partitioned cookies need partitioned: true. A prefix only finds cookies the current page can read, so use an exact name for a cookie on another path.

c15t never deletes its own consent records, even when a pattern matches them.

When cleanup runs

• On the first page load after the policy resolves, for every denied category. This covers a new opt-in visitor and a returning visitor whose choice expired.
• Whenever a category changes from allowed to denied, after a saved refusal, expiry, a policy change or a Global Privacy Control signal.

Cleanup does not run during server rendering, while the policy is still loading, on draft switch changes in the dialog, or when the provider unmounts. It runs once per change and does not poll. Under an opt-out policy, an expired choice that stays allowed deletes nothing. If a resolved policy later falls back to denial after a failed request, cleanup deletes the data, and a successful retry cannot restore it.

Switching off one vendor inside an allowed category deletes nothing, because the category stays allowed.

Browser limits

c15t can delete first-party cookies that JavaScript can read, and keys in the current origin's localStorage and sessionStorage. It cannot delete HttpOnly cookies or another origin's data; expire those from your server. A vendor SDK still running on the page can write its cookies again, which is one reason c15t reloads the page after a revocation. Deletion failures do not block the consent update. See MDN on cookies.

Verify cleanup

1. Allow measurement and let Google Analytics run. In DevTools Application, Cookies shows _ga and a _ga_<id> cookie.
2. Open Privacy settings, turn measurement off and save. c15t reloads the page. Both cookies are gone, and analytics:* keys are gone from Local storage.
3. Reload. The cookies do not come back, because Google Analytics no longer loads.
4. If you listed a cookie with an explicit domain or path, repeat step 2 and check that the cookie is gone from that scope too.