How do I check whether AI mentions my brand?

Nobody sells you this because there is no way to charge for it. Your access logs already contain the answer to "is anything from an AI company reading my site", and the user agents identify themselves clearly. Filter for OAI-SearchBot, PerplexityBot, Claude-SearchBot, GPTBot, ClaudeBot, ChatGPT-User, Claude-User and Perplexity-User.

Read them in two groups, because they answer different questions. The search crawlers, OAI-SearchBot, PerplexityBot and Claude-SearchBot, tell you whether you are eligible to appear at all. The user fetchers, ChatGPT-User, Perplexity-User and Claude-User, are more interesting: each hit is a real person, in a live conversation, whose question sent an assistant to your page. That is demand, and it does not show up in any analytics product.

Second, test it directly. Write down twenty questions a customer would ask, the ones where you should be the answer, and run the same list on the same day of each month across ChatGPT, Perplexity, Google AI Mode and Claude. Record whether you appear, in what position, and what it says about you. It is dull and it is the only measurement you will own outright.

Third, watch referrals. Assistants that link out send traffic with their own referrer, so ChatGPT and Perplexity show up as sources in analytics. On this site they are visible directly, which is how I know how small the numbers still are.

There is a category of paid tools that automate the second step across more prompts and engines. They are useful once you are running the test at a scale you cannot do by hand. I am not going to quote their coverage statistics at you, because I have not verified them and neither has anyone quoting them.

The order matters. Logs tell you whether you are readable, tests tell you whether you are chosen, referrals tell you whether it is worth anything. Most people start at step three and wonder why the number is zero.