Skip to main content
Home/Knowledge/Glossary/Opt-Out Signal
All glossary terms
Privacy & DataGlossary

Opt-Out Signal

A browser or device-level signal indicating a user's preference not to be tracked, such as Global Privacy Control (GPC).

Reference definitionAll

What Opt-Out Signal means

Opt-out signals are technical mechanisms that communicate a user's privacy preferences to websites and advertisers. The most significant is Global Privacy Control (GPC), a browser-level signal recognized under CCPA/CPRA as a valid opt-out of data sale/sharing. When a user enables GPC, businesses must treat it as a request to stop selling or sharing that user's personal information. The CPRA specifically requires businesses to honor GPC signals, and the California AG has confirmed enforcement. Other opt-out mechanisms include the NAI opt-out tool, DAA WebChoices, and Apple's Limit Ad Tracking setting. For advertisers, properly honoring opt-out signals requires technical implementation at the website level and integration with consent management platforms. Failure to honor recognized opt-out signals can result in regulatory enforcement under applicable privacy laws.

Related terms

Related Resources