Updated weekly · Last reading 27 July 2026

The AEO Citation Index

Every week we ask ChatGPT, Gemini, Perplexity, Claude and Google AI Mode to recommend a tool in the AI-visibility category, then count every source they cite. This is that count. No score, no weighting, no model of our own sitting between you and the number.

The sources the engines cite most

Reading of 27 July 2026. Share is that source as a fraction of all 601 citations in the sweep.

What the count says

Three of the top five sources are places you cannot buy your way into and cannot optimise with a meta tag. Reddit leads. YouTube is second. LinkedIn is fifth. Two established SEO vendors sit between them, and they are there on the strength of comparison posts, not product pages.

No vendor homepage in this category makes the top five, ours included. If you are trying to get an engine to name you, the work is not on your own site. That is an uncomfortable finding for a company that sells AI visibility, so we publish it rather than bury it.

How we measure it

1. 1. We run the same 34 buyer questions every week. They are the questions somebody actually types when they are choosing a tool in this category, not keyword variants.
2. 2. Each question goes to 5 engines through their live interfaces, not a training-data lookup.
3. 3. We record every source each answer cites, reduce it to a bare domain, and count. A domain cited twice in one answer counts twice.
4. 4. We publish the count. We never edit a past week. If the prompt set changes, the note on that week says so.

Every reading so far

Run it on your own category

This index covers one category, ours. Yours will have a different top five, and the five sources that decide who gets named in your market are the only ones worth your time. Get the same count for your own domain, free, no card.

The sweep behind the first reading is written up in full at zero mentions in 34 prompts, and the 200 pages behind those citations are listed at the pages AI cites in AEO.