Key takeaways
- AI visibility tools measure your brand's presence in ChatGPT, Gemini, Perplexity, and Google AI Overviews using three different methods: live browser/UI scraping, official APIs, or a mix of both, and the method changes the numbers you see.
- API-based and live-UI data frequently disagree. One vendor, MentionsAPI, openly admits its API data diverges from the live UI on 80-96% of prompts. Another agency test found API tracking overstated brand presence by 23 percentage points compared to what real users actually saw.
- Platform-side changes can swing citation counts overnight. Promptwatch's data shows ChatGPT's average citations per response dropped about 27% after the GPT-5.3 rollout on March 4, 2026, and its use of the site: operator in fanout queries jumped 46x in a single day on August 8, 2026. A snapshot audit would read either of those as