Global Privacy Control and Do Not Track
Your browser can send polite “please do not sell or share my data” signals. They are easy to enable — but not every site listens. Here is how they work and how to check yours are on.
What these signals do
Global Privacy Control (GPC) is a modern opt-out signal sent as the
Sec-GPC: 1 HTTP header and via JavaScript (navigator.globalPrivacyControl).
It tells sites you object to sale or sharing of personal data under laws like CPRA.
Do Not Track (DNT) is an older DNT: 1 header. Few sites
honor it today, but enabling both costs nothing and some publishers still check.
What they do not fix: fingerprinting, IP geolocation, Client Hints, or cookies. Trackers that ignore legal opt-outs can still collect technical signals. Pair GPC with anti-fingerprinting and cookie controls.
Related signals we detect today
- Privacy preference (HTTP) — Sec-GPC and DNT headers
- GPC (JavaScript) — globalPrivacyControl flag
- DNT (JavaScript) — doNotTrack property
- No privacy signals — combined check when all are absent
Step-by-step: enable opt-out signals
Firefox
- Settings → Privacy & Security → scroll to Website Privacy Preferences.
- Check Tell websites not to sell or share my data (GPC).
- Optional: set Send websites a “Do Not Track” signal to Always.
Brave
- Settings → Shields → enable Automatically send GPC.
Safari
- Settings → Safari → Advanced → enable options that limit tracking; GPC support varies by OS version — check Privacy settings for “Privacy Preserving Ad Measurement” and tracking prevention.
Chrome / Edge
- Install a GPC-supporting extension or use a browser with built-in GPC (Firefox, Brave). Chromium is adding GPC in some regions — check Settings → Privacy for “Send Global Privacy Control signal”.
Verify with the analysis tool
- Run live analysis.
- On Overview, look under protections — GPC/DNT should appear as active.
- Open the HTTP headers tab — confirm
Sec-GPCorDNTis present. - Check the JavaScript tab for globalPrivacyControl / doNotTrack values.
- If you still see a “no privacy signals” concern, re-check browser settings and extensions that might strip headers.
Confirm your browser is sending opt-out signals.
Check my GPC & DNTFrequently asked questions
Is GPC legally binding?
It exercises rights under some privacy laws, but enforcement depends on jurisdiction and the site’s compliance program. It is not a technical block on tracking.
Why enable DNT if sites ignore it?
It is harmless, takes one click, and some enterprise or regional publishers still read it alongside GPC.