Cookies and site data: what to block

Cookies are the best-known tracking tool — but fingerprinting works without them. Still, blocking third-party cookies and clearing site data closes a major tracking lane.

What cookies and site data enable

First-party cookies remember your login on a site you visited directly. Third-party cookies let ad networks follow you across many sites. Modern browsers also store data in localStorage, IndexedDB, and cache — “site data” is broader than cookies alone.

Our tool reports whether cookies are enabled in JavaScript — a coarse signal. The bigger privacy win is which cookies and storage trackers can set.

What this does not fix: passive fingerprinting (canvas, WebGL, fonts), IP geolocation, or Client Hints. See anti-fingerprinting.

Related signals we detect today

Cookies enabled — whether JavaScript reports cookies on
Request context — Sec-Fetch metadata about cross-site requests
Few headers — stripped or minimal header sets
Fingerprint strength — tracking without cookies

Step-by-step: tighten cookie and storage settings

Firefox

Settings → Privacy & Security → Enhanced Tracking Protection → Strict.
Under Cookies and Site Data → choose Delete cookies and site data when Firefox is closed if you accept more logouts.

Brave

Shields → Block cross-site cookies; consider blocking all third-party cookies globally.

Safari

Settings → Safari → Prevent Cross-Site Tracking; review Manage Website Data periodically.

Chrome / Edge

Settings → Privacy → Third-party cookies → Block third-party cookies.
Clear browsing data → Cookies and site data on a schedule you are comfortable with.

Verify with the analysis tool

Run live analysis.
Check JavaScript signals for cookies enabled — blocking all cookies may break the site itself; prefer third-party blocking.
Review Overview recommendations — cookie guidance appears when cookies are enabled without other protections.
Compare fingerprint strength before/after — score may change little if fingerprinting still works.

See how cookies and fingerprinting interact in your browser.

Run privacy analysis

Frequently asked questions

Should I block all cookies?

Usually no — you will be logged out everywhere. Block third-party and clear data periodically instead.

Does private browsing replace cookie blocking?

No. See private browsing limits — it only clears data when the window closes.

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