Recognize returning browsers even when cookies are cleared. With Collect browser fingerprint enabled in your application's Frontend tab, the JavaScript tag computes a fingerprint hash from system and browser specifics, such as locales, GPU properties, and available fonts, and attaches it to the captured events.

How it works

• The fingerprint is a stable hash like v1_<hash>, computed once per browser and cached locally.
• Every captured event carries the fingerprint, and the session-start event additionally includes the raw component data it was computed from.
• Because the fingerprint is derived from the browser itself rather than stored identifiers, it stays the same when the visitor removes cookies or uses a fresh session.

Use the fingerprint to correlate sessions coming from the same browser: filter or group events by the fingerprint field in Events, or query it over the SQL API.

Privacy considerations

While perfectly legal, privacy-focused users might dislike fingerprint collection. Review it against your privacy policy and the regulations that apply to you.

To turn it off, disable Collect browser fingerprint in your application's Frontend tab. The change takes effect immediately, no redeploy needed.

Prefer identified users where you can

Fingerprints recognize a browser, not a person. For signed-in traffic, identify users instead: identification is exact, survives browser changes, and powers the Users page.