The fr cookie is Facebook's primary advertising cookie used with the Facebook Pixel for ad delivery and retargeting.
Who sets it: Facebook, Inc., typically set via the Facebook Pixel or social plugins on websites.
What it does: Stores identifiers to deliver, measure and retarget ads and to link web activity to Facebook accounts; often paired with the _fbp cookie.
Duration: Expires after about 90 days.
Consent type: Advertising/marketing cookie — requires user consent in many jurisdictions.
Want to inspect it yourself? See how to inspect cookies in your browser.
If you run Facebook ads, include the fr cookie in your cookie controls and consent notices and monitor it via your browser's cookie inspector.