What is the __gsas cookie?
__gsas is an HTTP cookie associated with the Google Ads platform (formerly Google AdWords), typically used in connection with conversion tracking and ad campaign measurement features.
It appears on a website when that site runs Google Ads conversion or remarketing scripts (for example the gtag.js tag or a conversion tracking snippet), being set by Google's JavaScript code when the page loads or after a visitor interacts with an ad.
What data it stores
The cookie generally stores a unique identifier tied to the browsing session, used to link a website visit back to a previous Google Ads campaign interaction. The exact value format is not publicly documented by Google and may vary.
The data is sent to Google's servers, mainly for processing conversion statistics and optimizing ad campaigns.
What it is used for
For Google, __gsas helps attribute a conversion (purchase, form submission, click) to a specific ad or campaign, enabling measurement of advertising return on investment (ROAS).
For the website owner, this cookie underpins conversion reporting inside Google Ads, providing data on campaign effectiveness and supporting advertising budget optimization.
Does it require consent?
__gsas is classified as a marketing (advertising/tracking) cookie. Under the ePrivacy Directive and GDPR, this category requires the visitor's prior, informed and explicit consent before being set.
The website operator must list it in the cookie policy, include it under the “marketing” category of the consent banner, and ensure the Google Ads script does not load before the visitor has given consent.
How to block or delete __gsas
A visitor can delete or block this cookie through browser settings (Chrome, Firefox, Edge, Safari – per-site cookie management), or by using dedicated ad-tracking blocker extensions.
- At the website level, the Google Ads script must be loaded conditionally, only after consent is given.
- A CMP like CookieFix automatically blocks marketing scripts, including Google Ads ones, until the visitor explicitly accepts this cookie category.
Frequently asked questions
It is a marketing cookie used by Google Ads to track and attribute conversions generated by Google advertising campaigns.
It is set by Google Ads scripts (gtag.js or a conversion tag) installed on the visited website, not directly from a Google domain.
Its typical duration is around 13 months from the last interaction, though this can vary depending on configuration.
Yes, as a marketing/tracking cookie it requires prior consent under GDPR and ePrivacy, and the script must be blocked until consent is given.