Do AI engines cite their own websites?

A page citation is one cited page in one AI answer. The matched prompt set is the same organic prompts run on both engines. Ownership is assigned by registered domain, never by brand name, because brand names collide: Gemini is also the name of a crypto exchange.

Google AI Mode cited at least one Google-owned page on 15,833 of 18,304 matched prompts, or 86.50%. ChatGPT Search did so on 2,014 of the same 18,304 prompts, or 11.00%. That is 7.86 times as many prompts. Two separate ways of counting returned identical numbers.

Google-owned pages account for 351,377 of Google AI Mode's 3,199,278 citations in the matched prompt set, or 10.98%. They account for 5,608 of ChatGPT Search's 1,014,999, or 0.55%.

The ratio is 19.88 to 1. Put another way, about one Google AI Mode citation in nine points to a page Google owns, against about one in 181 for ChatGPT Search.

Of Google AI Mode's citations in the matched prompt set, YouTube accounts for 5.84%, Google's search and shopping result pages for 4.13%, other Google.com pages for 0.84%, and Google product and documentation sites for 0.18%.

The equivalent ChatGPT Search shares are 0.08% for YouTube, 0.0003% for search and shopping pages, 0.02% for other Google.com pages, and 0.45% for product and documentation sites.

If one engine simply cited large sites more often, every large domain would move the same way. Domain groups owned by neither engine do the opposite: Apple.com runs 0.72, Reddit.com 0.62, Microsoft.com 0.26, and wikipedia.org 0.18, meaning ChatGPT Search cites all four more often than Google AI Mode does.

Google-owned pages run 19.88 times more common on Google AI Mode. OpenAI-owned pages run 0.09, meaning ChatGPT Search cites them 10.54 times more often. Amazon is the one other elevated group at 9.00.

Google product and documentation sites account for 0.45% of ChatGPT Search citations and 0.18% of Google AI Mode citations, or 2.55 times more. On cloud.Google.com, ChatGPT Search recorded 1,260 citations against Google AI Mode's 911. On workspace.Google.com it recorded 350 against 164, and on developers.Google.com 215 against 167.

Google's engine sends readers to Google's own pages. The competing engine sends them to Google's documentation.

Google AI Mode cited YouTube.com 186,832 times across 14,822 of the 18,304 matched prompts, or 80.98% of prompts. ChatGPT Search cited YouTube.com 801 times. Google.com follows with 158,866 Google AI Mode citations across 5,799 prompts, against 211 for ChatGPT Search.

Two properties account for nearly all of the difference between the engines.

On a matched set of 17,191 prompts, Google AI Mode recommended an Alphabet-owned brand on 2,090 prompts, or 12.16%, and ChatGPT Search on 2,038, or 11.86%. The ratio is 1.03.

At the product level the two engines are close on almost every brand. Google AI Mode named Google on 513 prompts and ChatGPT Search on 514. Google AI Mode named Google Cloud on 218 against 202, and Google Gemini on 171 against 175. ChatGPT Search named Google Cloud Looker on 107 against 38 and Google Cloud BigQuery on 84 against 33.

ChatGPT Search cited an OpenAI-owned page on 434 of 18,304 prompts, or 2.37%, against Google AI Mode's 141, or 0.77%. The ratio is 3.08. At the citation level the shares are 0.11% and 0.01%.

Both engines lean toward their owner's properties, but the magnitudes are not comparable. Alphabet operates YouTube and a search product; OpenAI operates few content properties.

The matched set keeps 18,304 of the 18,489 prompts that drew a citation in the window, dropping 185 seen on only one engine. Removing the restriction moves Google AI Mode's Google-owned citation share from 10.9830% to 10.9782% and ChatGPT Search's from 0.5525% to 0.5526%, so the matched set is not producing the result.

Ownership is assigned by registered domain, so an owned property on an unrelated domain is not counted. Google AI Mode records roughly three times as many citations in the matched prompt set as ChatGPT Search, which is why every comparison uses each engine's own share rather than raw counts.

Google AI Mode cited a Google-owned page on 86.50% of prompts against ChatGPT Search's 11.00%, concentrated in YouTube and Google's search and shopping pages, while brand recommendations sat at 12.16% against 11.86%.

Track citation share and recommendation share as separate measures, per engine. Treat video as something that matters on Google AI Mode specifically, because YouTube reached 80.98% of prompts there and almost none on ChatGPT Search. Keep product documentation current, because documentation is what earned citations on the engine the parent company does not operate. Do not read a rival's citation count on one engine as evidence that the engine recommends them.