Write-up claims an OpenAI ad pixel ties web browsing to ChatGPT accounts

An independent reverse-engineering write-up says OpenAI runs an ad-measurement pixel at bzr.openai.com. According to the write-up, it sets a cookie across openai.com that lasts a year, so any advertiser site embedding the pixel pings OpenAI and can tie a visitor's browsing to their ChatGPT-linked identity.

This is a reported claim from one technical source. OpenAI hasn't responded and nobody else has reproduced it yet.

Why it matters

People tell ChatGPT unusually personal things. Ad-measurement infrastructure linked to those accounts would be a significant shift.