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We make responses to privacy choices transparent and verifiable for everyone.

Twelve US states require businesses to honor a universal opt-out signal, and from January 1, 2027, California's AB 566 requires browsers to offer one. Nobody can see whether a site honored it. GPC Inspector, our free extension, shows what each site did.

Get it for Chrome Also for Brave and Edge. Free, open source.

8,000 users4.5 of 5 on the Chrome Web StoreFeatured extension

The GPC Inspector popup on an example store page. The Global Privacy Control signal is set by this extension. The page showed a GPC confirmation, and the site declares GPC support in its gpc.json file. Its Global Privacy Platform string has the GPC field set and records an opt-out. Scripts from two vendors, one advertising and one consent manager, read GPC. Zero third-party cookies were set by advertising or analytics vendors while the signal was on.
The popup on a page after the signal was sent. Illustrative data.

Three people need the same facts.

The person who sent the signal

Sees what the site did with it, on the page they are on, instead of a promise in a policy.

The engineer who keeps the site honoring it

Checks every deploy against what the browser observed, with a record to hand over.

The counsel who has to prove it did

Gets dated facts anyone can reproduce, in place of a vendor's score.

GPC Inspector

A free, open-source extension for Chrome, Brave and Edge that shows what the current website did with the Global Privacy Control signal your browser sent. Every finding can be exported as a record. Nothing is sent to us.

  • What was sent, and whether this extension, the browser or another extension sent it.
  • What the site did: which scripts read the signal, whether it publishes a GPC support file, whether a confirmation appeared.
  • What its consent strings told third parties about your choice, decoded.
  • Who set cookies anyway, by company and category, with the request that carried each one.

Get it for Chrome Also for Brave and Edge. How it works

The vendor list in the GPC Inspector popup on an example news page. Five advertising vendors are listed with the cookies each one set. Two read GPC through the GPP consent API, one read the GPC property, and for two no read was observed. The first vendor's row is open: 12 of 12 requests carried the signal, and of its two cookies one was sent back to the vendor.
The vendor list: who read the signal, and which cookies went back. Illustrative data.

For companies

If your team checks GPC with the extension, tell us what you check and what you wish you could. We are talking to privacy engineers and counsel now.

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