What is the ljtrtb cookie?
ljtrtb is an HTTP cookie set by Sovrn, a US-based advertising technology (adtech) company formerly known as Lijit, which operates a content monetization and programmatic advertising platform used by publishers and ad networks.
The cookie typically appears when a website embeds a Sovrn ad tag, content widget, or a partner script that resells advertising inventory through the Lijit/Sovrn infrastructure. It is stored on the .lijit.com domain, so it shows up as a third-party cookie for visitors of the site that integrates it.
What data it stores
ljtrtb generally stores a unique identifier generated for the visitor's browser, used to recognize it across repeat visits on different sites running Sovrn's infrastructure. The exact format of the value is not publicly documented and may vary.
Data linked to this identifier (ad interactions, sites visited within the Sovrn network) is sent to Sovrn/lijit.com servers and may be shared with advertising partners in the programmatic bidding chain.
What it is used for
For Sovrn, ljtrtb helps build a cross-site browsing profile needed for real-time bidding (RTB) and for targeting ads to relevant audiences.
For the website operator, this cookie supports monetization through ads served via Sovrn, but it also comes with an obligation to inform visitors and obtain consent, since it is a tracking cookie rather than one strictly necessary for the site to function.
Does it require consent?
ljtrtb is classified as a marketing/advertising cookie. Under the ePrivacy Directive (as implemented in Romania by Law 506/2004) and the GDPR, this type of cookie requires the user's prior, explicit consent before being placed.
- It must be listed in the cookie policy under the marketing category, naming Sovrn/Lijit as the provider.
- The script that generates it should not run before the visitor has accepted the marketing category.
- Data protection authorities (in Romania, ANSPDCP) can sanction placing such cookies without valid consent.
How to block or delete ljtrtb
A visitor can delete or block ljtrtb from browser settings (Chrome, Firefox, Edge, Safari — per-site or per-domain cookie management), or use ad-tracker blocking extensions.
For site owners, proper blocking means the Sovrn script never executes before consent is given, not just deleting the cookie afterward. A CMP such as CookieFix can automatically block marketing scripts, including ones that set ljtrtb, until the visitor gives consent for that category.
Frequently asked questions
It's a marketing cookie set by Sovrn (Lijit) to identify a browser for programmatic advertising and ad measurement purposes.
It's set on the .lijit.com domain by the adtech company Sovrn, when a site integrates tags or widgets from their advertising network.
No, it's an advertising tracking cookie, not strictly necessary, so it requires visitor consent under GDPR/ePrivacy rules.
The typical observed duration is 1 year, after which it expires automatically unless renewed by a new visit to a site in the Sovrn network.