Extension

Privacy policy

This covers the CrawlCheck browser extension. It is short because the extension collects nothing, and every claim below is checkable by reading the source.

What is collected

Nothing is collected and nothing is transmitted to us about your browsing. The extension contains no analytics, no remote code and no advertising network. It has no POST, no sendBeacon and no XMLHttpRequest; every network call it makes is a GET.

What stays on your device

• Measurements you run, held in the browser's local and session storage so a repeated check does not re-request a site. They are never sent anywhere and you can clear them by removing the extension.
• Your licence key, if you have one.
• The last run, so the popup reopens where you left it.

The one request that reaches our server

If — and only if — you enter a licence key, the extension calls GET /api/licence/check with that key, at most once every 24 hours, to confirm the licence is valid. It sends the key and nothing else: no URL, no page content, no measurement. Users without a key never make this request.

Requests to sites you measure

When you measure a page, the extension requests it as each named crawler and as your browser. Those requests are sent with credentials: "omit", so your cookies, sessions and logins are never attached and the site cannot identify you from them. The extension identifies itself honestly and does not impersonate an operator's crawler to obtain access it would not otherwise be given.

Sharing and sale

There is no data to share, so none is shared, sold, or transferred to third parties. It is not used for advertising, for creditworthiness, or for lending. It is not used to train anything.

Permissions, and the feature each one exists for

• declarativeNetRequest — a request cannot set its own User-Agent from a page, so a session rule is the only supported way to ask for a page as a named crawler. One rule exists at a time and it is removed in a finally block.
• scripting and activeTab — read timings, cookie-present state and the rendered DOM of the tab you are looking at, when you ask. It reads and returns; it writes nothing to the page.
• tabs — read the active tab's address so the popup measures the site you are on.
• storage — the local items listed above.
• contextMenus — one right-click item.
• Host access to all sites — you choose which site to measure and it is not a site we can predict. That choice is the entire function.

Changes and contact

Material changes will be published on this page with the date they took effect. Questions: hello@crawlcheck.io.

Last updated 14 August 2026. Applies to extension version 0.7.0 and later.