What is Criteo and why block this domain?
Understand how Criteo, an ad company based on tracking, operates and why privacy tools block its domain.
Drafted by automation from the sources listed at the end of this page, and reviewed before publishing. The sources are the part that matters: check them.
What is the Criteo domain?
The domain criteo.com belongs to Criteo S.A., a French online advertising company founded in 2005. It specializes in display advertising based on retargeting, showing interactive banners personalized according to the user’s browsing behavior.
Who operates the domain?
Criteo was founded by Jean-Baptiste Rudelle, Franck Le Ouay, and Romain Niccoli, headquartered in Paris, France. Currently led by CEO Michael Komasinski (since February 2025), the company went public in 2013 and announced plans to move its headquarters to the United States via Luxembourg by the end of 2025.
What does Criteo do with browsing data?
Criteo collects anonymous information about users’ browsing on partner sites (e.g., online stores) to display personalized ads. According to the company, it does not use personally identifiable information (PII) nor share data with advertisers or third parties. The model is pay-per-click (CPC): advertisers pay only when the user clicks the ad.
In practice, Criteo uses cookies and other tracking technologies to follow users across sites, recording viewed products and visited pages. This enables retargeting ads showing items the user previously considered purchasing.
Why do privacy tools block Criteo?
Despite claims of anonymity, Criteo has faced investigations and fines for privacy violations:
- In 2019, Privacy International and NOYB (led by Max Schrems) filed complaints against Criteo for GDPR non-compliance.
- In June 2023, the French data protection authority CNIL imposed a €40 million fine on Criteo, mainly for failing to verify that users properly consented to data processing.
Additionally, browsers like Safari (with Intelligent Tracking Prevention) have limited Criteo’s tracking, impacting its revenue. Ad-blocking and DNS-based tools (e.g., AdGuard) often block criteo.com because it is a domain for tracking and ad delivery.
Limitations of DNS blocking
Blocking criteo.com via DNS prevents connections to Criteo’s servers but has limitations:
- Does not remove ads served from the same domain as content: if a site serves Criteo ads from its own domain, the block won’t remove them.
- Does not hide your IP: DNS blocking only prevents domain resolution; your IP address remains visible to other services.
- May break site functionality: some sites may display broken content or load slowly if they depend on Criteo scripts.
For more comprehensive protection, combine DNS blocking with browser anti-tracking extensions and, if desired, solutions like hAD99, which filters ads and trackers at multiple layers.