GPC & Opt-Out Checker: Check My MarTech Data by DigiBiz360

GPC Compliance Checker is a free tool from DigiBiz360, which also offers paid GPC audit and remediation services. It sends Global Privacy Control (GPC), the browser opt-out preference signal, and shows which known ad and analytics vendors a website contacts with GPC on and off. Checks for an opt-out status message, detects the consent manager, and flags ad cookies written with GPC on. While it's on, the extension sends GPC to every site you visit, as privacy-focused browsers do. If known ad vendors receive requests on a page after GPC is sent, the toolbar icon shows how many. Open the popup to see which vendors and the exact requests. For a comparison, run the before/after test. The extension reloads the page once without GPC and once with it, then shows vendor by vendor which requests stopped and which continued. Results use plain, observation-based labels such as "No ad-vendor requests seen with GPC on" or "Ad-vendor requests continued with GPC on." What it does: - Sends the Sec-GPC header and the navigator.globalPrivacyControl signal - Shows a count of known ad vendors receiving requests with GPC on - Runs a one-click before/after test with vendor-by-vendor results - Lists the exact requests observed, and separately lists requests sent with a vendor restricted-processing flag - Copies test results as plain text - Shows site signals: whether the page detects GPC, consent manager status, and gpc.json Who it's for: privacy, marketing, and engineering teams checking their own websites, and agencies and consultants reviewing sites they're authorized to review. Important: results are technical observations of a single page load in your browser, not legal conclusions or compliance certifications. The extension cannot see server-side data sharing, and many sites behave differently by location or consent state, so results may be incomplete or inaccurate. Not legal advice. Tests run locally. If you click "Get a paid audit," the tested domain, result, and vendor names are sent to digibiz360.com. Not affiliated with or endorsed by the CPPA, any Attorney General, the GPC project, Google, or any vendor named. Terms: digibiz360.com/gpc-extension/terms · Privacy: digibiz360.com/gpc-extension/privacy · Methodology: digibiz360.com/gpc-extension/methodology