What is the tt_sessionId cookie?
tt_sessionId is an HTTP cookie associated with TikTok's services, typically set when a website has TikTok Pixel or other TikTok advertising scripts installed (for example, share buttons or embedded TikTok content). It appears in the browser as soon as the TikTok script loads and runs on the page, regardless of whether the visitor has a TikTok account.
It is set either directly by TikTok or by the website running the TikTok integration, as part of the browsing session identification mechanism.
What data it stores
The cookie stores an automatically generated session identifier used to distinguish one visit from another for the duration of the active browser session. TikTok does not publish detailed documentation on the exact value format, and it may vary; no specific public details are known about particular subdomains used.
Data collected through this cookie is sent to TikTok's servers and may be correlated with other browsing behavior data to build user profiles for advertising purposes.
What it is used for
The main purpose is to support TikTok's advertising and measurement functions: session tracking, attributing conversions from TikTok Ads campaigns, and optimizing ad targeting based on user behavior across partner websites.
For a website owner, the presence of this cookie is usually a side effect of embedding TikTok widgets or a conversion pixel, rather than being necessary for the site's technical functioning.
Does it require consent?
In CookieFix's classification, tt_sessionId falls under the marketing category. Under the ePrivacy Directive (implemented in Romania via Law 506/2004) and the GDPR, this type of cookie requires the visitor's prior, explicit consent before it is placed.
The site administrator must declare it correctly in the cookie policy, include it in the marketing category of the consent banner, and ensure the TikTok script does not load before the visitor gives consent.
How to block or delete tt_sessionId
A visitor can manually delete or block this cookie through browser settings (Chrome, Firefox, Edge, and Safari all allow deleting individual cookies or blocking third-party cookies), as well as through tracker-blocking browser extensions.
- For site administrators, the most reliable approach is using a consent management platform (CMP) like CookieFix, which automatically blocks TikTok scripts from loading until the visitor accepts the marketing category.
- Without such a technical blocking mechanism, simply displaying an information banner is not sufficient for compliance.
Frequently asked questions
It is not malicious, but it is a tracking cookie used for advertising purposes, which is why it requires visitor consent under the GDPR.
It is a session cookie, meaning it typically expires when the visitor closes their browser.
Yes, since it is classified as a marketing cookie, it requires the user's prior consent before being placed on the site.
It appears when a website embeds TikTok scripts, such as the TikTok Pixel, share buttons, or embedded video content from the platform.