"GPC signal detected" means your browser, or an extension in it, is sending Global Privacy Control: a signal that asks every site you visit not to sell or share your personal information. In California, a site that sells or shares personal information must treat that signal as a valid opt-out. The message itself is harmless, and nothing is wrong with your device.
The box below reads the signal from the browser you are using right now.
Checking your browser…
Where the message comes from
You will usually see "GPC signal detected" in one of three places.
- The globalprivacycontrol.org test page. It reads the signal your browser sent and confirms it at the top of the page.
- Another site's privacy or cookie banner. Many consent tools show a short note when they see the signal, so you know the site received it.
- Your own site's consent tool or analytics, if you run a website. That case has its own section below.
What is sending the signal
Some browsers send GPC for everyone, some have a setting, and some need an extension.
- On by default: Brave and the DuckDuckGo browser. The DuckDuckGo Privacy Essentials extension sends it from install too.
- A setting: Firefox, under Privacy & Security.
- An extension: Chrome, Edge, and Safari have no built-in switch, so the signal comes from an extension such as Privacy Badger or a privacy or security add-on.
If you never turned anything on, look at your extensions first. A tracker blocker or security extension installed for other reasons often sends GPC as well. The full breakdown, with how to confirm the signal in DevTools, is in which browsers send the GPC signal.
Does GPC break websites?
No. GPC is a request, not a blocker. It does not hide content or stop scripts from loading. When a page breaks at the same moment the message appears, the cause is usually something next to it: the blocking features of the extension that sends GPC, or the site's own consent script.
Here is one public example. In Xfinity's support forum, Chrome users saw a "GPC Signal Detected" bar above a blank channel guide. What restored the listings, they reported, was disabling a security extension, not changing anything about GPC. To test a broken page yourself, open it in a private window with extensions off. If it works there, an extension is the cause.
How to turn the GPC signal off
- Firefox: open Settings, choose Privacy & Security, find Website Privacy Preferences, and uncheck "Tell websites not to sell or share my data".
- Brave and the DuckDuckGo browser: the signal is part of the browser, with no switch. Use a different browser for the site in question.
- An extension: look for a GPC or "do not sell" option in the extension's settings, pause the extension on that site, or remove it.
Reload this page afterwards and the live check above will confirm the change. With GPC off, sites stop receiving the request automatically. You can still opt out on any site through its "Do Not Sell or Share" link.
If you saw it on your own website
A consent tool that says "GPC signal detected" has done the first step: it noticed the signal. The CCPA asks two more questions, and the message answers neither.
Did the selling and sharing actually stop? For a browser sending GPC, the advertising pixels and tags that sell or share personal information must not fire as normal. Detecting the signal does not stop them. In our benchmark of 1,019 commercial domains, 466 still loaded marketing trackers after receiving GPC.
Does the visitor know it worked? Since January 1, 2026, regulation § 7025(c)(6) requires a business that sells or shares personal information to display whether it processed the signal as an opt-out request. The regulation's example wording is "Opt-Out Request Honored". "GPC signal detected" reports that the signal arrived, not what you did with it. Privisy's scanner counts detection-only wording as a status display but flags it, and recommends wording that says the opt-out was processed.
To check both halves, load your site with GPC on and watch what fires afterwards. How to honor the GPC signal covers the setup, and GPC not working on your site works through the usual failures in order.
Frequently asked questions
Is "GPC signal detected" a warning or a virus?
No. It is a status message. A site, or the globalprivacycontrol.org test page, is telling you it received the Global Privacy Control signal from your browser. Nothing is wrong with your device.
Does GPC block ads or content?
No. GPC is a request not to sell or share your personal information. It does not block scripts, ads, or page content. If a page breaks at the same time, the cause is usually an extension's other features or the site's own consent script.
Is the GPC signal legally binding?
In California, a business that sells or shares personal information must treat GPC as a valid request to opt out of that sale or sharing (CCPA regulation § 7025). Several other states also require businesses to honor universal opt-out signals.
Does GPC tell the site who I am?
No. The signal is a single value, Sec-GPC: 1, sent with each request and exposed to page scripts as navigator.globalPrivacyControl. It carries no name, email, or identifier.
What should a site show when it detects GPC?
Since January 1, 2026, CCPA regulation § 7025(c)(6) requires a business that sells or shares personal information to display whether it processed the signal as an opt-out. The regulation's example wording is "Opt-Out Request Honored". A message that only says the signal was detected reports the signal, not the outcome.
See what your site does with the signal
Our free GPC checker loads one URL with Global Privacy Control set and reports whether third-party trackers still fire.
Run a free GPC check