There is no list of the most-cited documentation domains. The format has been measured, and only cleanly on ChatGPT. In August 2026, Promptwatch saw documentation move from 3.3% to 8.2% of the citations it could classify. Product pages were the large slice, averaging 28.7%. A B2B panel that bundles docs with product pages gets to about 30%, which is a different cut wearing a similar number.
- Documentation is real on ChatGPT and it is not the main format. Single digits for most of August, 8.2% at the end, inside classified citations.
- Product pages averaged 28.7% and were the largest labelled type. They held near 30% until 22 August, then fell to about 25%.
- Resonance's "about 30%" is docs plus product pages on ChatGPT, inside a B2B technology panel of 1.3 million citations. It is not a documentation share, and it is not all-topic.
- No common-sample table exists for Gemini, Perplexity, AI Overviews, AI Mode, or Copilot. A claim that docs are 30 to 40 percent on every engine was not opened with a sample and is not used.
- Promptwatch does not say what fraction of citations the classifier labelled. A rise from 3.3% to 8.2% can be a real shift inside the labelled set and still not be a shift in all citations.
No domain list, and no common sample
A documentation leaderboard would name developer.mozilla.org, cloud vendor docs, Stripe, Twilio, and the rest, with shares. That ranking was not published in the studies opened for this series. Broken chain for a top ten of doc hosts. The page that can be written is the format share, which is what a team can act on while the host list is missing.
What was measured on ChatGPT
Promptwatch, August 2026, ChatGPT Search. Product pages were the largest labelled type at 28.7%. Documentation is not one of the slices in the summary bar. The prose says it rose from 3.3% in the first week to 8.2% over the last nine days. How-to pages rose from 4.3% to 9.1% over the same end window. Landing pages fell from about 20% in the first week to under 12%.
The interesting movement is the swap inside the month. Commercial landing pages lost share. Docs and how-tos gained it. That is a ChatGPT series, one month, one classifier. It is not a law of AI search. It is the only repeated format read that separates documentation from the product page next to it.
Ahrefs' December 2025 study of "best X" source URLs puts documentation, including PDF, at 7.6% of software source URLs, against 0.4% for agency queries and 0.8% for product queries. General landing pages were 37.2% of software sources. That is the mix inside best-list citations, not a cross-engine documentation share. Software queries are where docs would be expected to show up, and even there they are a small slice of the cited URLs.
The 30% figure bundles two formats
Resonance and Agentcy audited more than 1.3 million citations in almost 190,000 answers about 116 B2B technology brands, October 2025 through September 2026. Their line is that ChatGPT leans harder on documentation and product pages than the other assistants, and that those two page types together took about 30% of its citations. Separately, documentation earns about one in eight citations to brands' own sites. That second figure is a share of owned-site citations, not of all citations.
Read next to Promptwatch, the 30% is plausible as product pages plus a single-digit doc share, on a prompt set that is all technology brands. It is not evidence that a docs site is 30% of ChatGPT. Blog posts and articles were 22% of citations overall in the same panel. Best-of and comparison pages were under 2% of ChatGPT's citations and about 14% of Perplexity's. The engines do not even agree on which commercial format to cite.
Indexly's May to July 2026 Perplexity panel, buyer intent, prompt count undisclosed, puts docs and developer at 6% of citations. Useful as a second single-digit reading. Not comparable enough to plot against Promptwatch.
What this does not prove
Open question It does not name the winning doc domain. It does not say a docs rewrite will move citation share by the August delta. The August move is an observation inside one panel. Claude Code's heavy documentation visits are a browsing pattern on a coding agent, and Profound measured them as visits. Importing that into a ChatGPT citation plan mixes two products.
How to use it
Keep the reference page and the product page as separate URLs. The product page is the format with the large measured share. The doc page is the format that gained inside one month and that, on software "best of" citations, still beat a blog post's usual role as the only asset. The page-level mix, including how small the blog-post share was inside ChatGPT's most-cited thousand, is on most-cited pages.
Documentation rose from 3.3% to 8.2% of classified ChatGPT citations in August 2026. Product pages were near 29%. They are not the same format.
Share on XVerification status
Promptwatch's prose figures are kept separate from Resonance's bundled 30%. A Presenc claim that technical documentation is 29% of all citations, with no visible sample, was not used. No documentation domain was ranked by guesswork.
Namdev, R. (2026). Most-cited documentation domains in AI search (v1). Retrieved from https://ritiknamdev.com/blog/most-cited-documentation-domains-ai-search Published under CC BY 4.0 — reuse freely with attribution.
The page-type cut that includes homepages and guides is most-cited pages.