ChatGPT became an advertising platform in under a year: auctions, product feeds, conversion tracking, officially launched in nine countries, and, per OpenAI's announcement of 19 August 2026, expanding to 31 European markets from next week, including the Netherlands. One thing is missing. Google operates an Ads Transparency Center and Meta an Ad Library, but for ChatGPT there is no public record of who advertises, what they claim, or where the clicks go. Advertisers see their own dashboards; everyone else sees nothing.
Today we close that gap. PromptAds, our free Chrome extension, is now available in the Chrome Web Store, and with it the European ChatGPT Ad Library: a public register of advertisements in ChatGPT, built by real users.
How it works
PromptAds logs every sponsored placement ChatGPT shows you: advertiser, headline and copy, destination link, campaign tags and format. The log lives in your browser, is searchable and filterable, and exports to CSV in one click. For marketers and agencies that makes every teammate's browser a data point: who targets your market's conversations, with which creatives, toward which landing pages.
Contributing to the library is strictly opt-in and off by default. When you opt in, PromptAds shares the ad and only the ad: never your conversations or prompts, no names, no stored IP addresses. The consent screen lists exactly what leaves your browser before anything does.
Why real users beat bots
Existing ChatGPT ad trackers rely on synthetic accounts firing thousands of prompts through proxy networks. That approach can sample the market, but it cannot see what real, logged-in, possibly personalised delivery looks like. A consent-based panel of real users can. That is the library's difference, and in Europe, doing this privacy-first is not a footnote; it is the point.
The window is now
On 19 August, De Telegraaf interviewed our founder Arjan ter Huurne about ChatGPT's ad rollout reaching Europe. That same day, OpenAI made it official: ChatGPT Ads expand to 31 European markets, with ads reaching Free and Go users from the week of 24 August and self-service buying through the Ads Manager following later this summer. The core message stands: the channel is arriving faster than the transparency around it. Our own monitoring shows the ad layer running at full speed internationally, with 165 distinct advertisers and over 800 sponsored placements counted in a single US B2B category in ninety days, while Dutch consumer prompts still show zero ads. That gap closes next week, and when the first European ChatGPT ads appear, the library will document them from day one.
Add PromptAds to Chrome via the Chrome Web Store, browse the European ChatGPT Ad Library, and if you want to understand what this channel means for your brand before your competitors do, read our ChatGPT Ads service page or talk to us.