What is the tluid cookie?
tluid is an HTTP cookie set from the .3lift.com domain, belonging to TripleLift, a US-based company specializing in programmatic advertising (real-time bidding) and native advertising integrations.
The cookie typically appears on websites that display ads served through advertising intermediary chains (ad exchanges, SSPs, or DSPs) where TripleLift participates in auctions. In practice, if a site shows banners or native ads originating from ad networks that work with TripleLift, this cookie can be set in the background, often without the site owner configuring it directly.
What data it stores
tluid stores a unique, randomly generated identifier assigned to the visitor's browser. The exact value format is not publicly documented in detail and may vary; TripleLift does not publish full specifications of the identifier's internal structure.
The value is sent to TripleLift's servers (the 3lift.com domain) on subsequent visits to sites within their advertising network, allowing the same browser to be recognized across different bidding contexts.
What it is used for
The main purpose of the cookie is to uniquely identify a visitor during the real-time bidding (RTB) advertising process. TripleLift uses this identifier to link browsing activity to a pseudonymous profile, useful for:
- targeting ads based on estimated interests;
- measuring and reporting ad campaign performance;
- limiting how often the same ad is shown (frequency capping);
- preventing ad fraud by recognizing suspicious traffic.
For the site owner, the presence of this cookie is usually a side effect of integrating advertising networks rather than a direct choice.
Does it require consent?
tluid falls under the marketing/advertising category per CookieFix's classification, used exclusively for tracking and ad targeting. Under Romanian Law 506/2004 (transposing the ePrivacy Directive) and the GDPR, this type of cookie requires the visitor's explicit prior consent before it is set.
Site owners must identify all advertising scripts that can trigger this cookie (directly or through intermediaries) and disclose them clearly in the cookie policy, including the purpose, provider (TripleLift), and storage duration.
How to block or delete tluid
A visitor can delete or block this cookie through browser settings (Chrome, Firefox, Edge, Safari), in the per-domain cookie management section, by searching for 3lift.com. Ad-blocking or tracking-protection extensions can also prevent it from being set in the first place.
For site owners, the correct approach is to automatically block advertising scripts until consent is obtained. A CMP platform like CookieFix can stop scripts that generate tluid-type cookies from loading until the visitor explicitly accepts the marketing category, preventing unauthorized cookie placement before consent.
Frequently asked questions
It is a marketing cookie set by TripleLift, used to uniquely identify a visitor during real-time ad bidding processes.
It is not dangerous in a technical sense, but it is a tracking tool that can profile browsing behavior for advertising purposes, which is why it requires consent.
Its typical duration is about 3 months, after which it expires automatically, though it can be renewed on later visits if the visitor accepts the marketing category again.
Yes, since it is a marketing/tracking cookie, the law requires the visitor's explicit consent before it is placed, under the GDPR and Romanian Law 506/2004.