How Do You Fact-Check Content Written for AI Search?

How do you fact-check content written for AI search?

Check every claim at its source, not in the draft: copy each quote word for word from the page it came from, match each number to the figure, period and range that page gives, and open every link to confirm it says what you cite it for.

AI search raises the cost of an error, because its answers are assembled from pages like yours. Google's AI optimization guide says its AI features rely on its core Search ranking systems to retrieve relevant, up-to-date web pages from the Search index.

Checkable proof also helps a page inside those answers. A 2024 paper on generative engine optimization (GEO) found that citing sources, adding quotations and adding statistics improved visibility by a relative 30-40% on one measure and 15-30% on another.

The GEO authors say citations are particularly beneficial for factual questions, likely because citations provide a source of verification for the facts presented.

Few readers check for themselves. In Pew Research Center's July 2025 analysis of Google searches, users clicked a link inside an AI summary in just 1% of visits to pages that showed one. Pew found users who saw an AI summary clicked a traditional result in 8% of visits, against 15% for those who did not.

Google's guidance on AI-generated content is blunt about this step: "It is critical to manually factcheck and review all AI-generated content for accuracy and trustworthiness before publishing".

What goes wrong when AI helps write the draft?

Language models write what sounds likely, and a likely-sounding fact can be false. Google's guidance says generative models "don't retrieve facts, but predict a likely sequence of words based on their training data".

OpenAI's September 2025 research note defines hallucinations as plausible but false statements generated by language models. OpenAI says they happen because standard training and evaluation procedures reward guessing over acknowledging uncertainty.

The failures have public records:

• Invented citations. A study in the journal Scientific Reports, published in September 2023, checked 636 citations in 84 short literature reviews ChatGPT wrote on 42 topics. It found 55% of the GPT-3.5 citations and 18% of the GPT-4 citations were fabricated.
• Legal tools that hallucinate. A preregistered Stanford study posted in May 2024 found AI legal research tools from LexisNexis and Thomson Reuters each hallucinated between 17% and 33% of the time.
• Fake opinions filed in court. In Mata v. Avianca in June 2023, a federal court in New York found lawyers had submitted non-existent judicial opinions with fake quotes and citations created by ChatGPT. The court imposed a $5,000 penalty on the lawyers and their firm.
• A refund over made-up references. The Guardian reported in October 2025 that Deloitte would partly refund a $440,000 report for Australia's federal government after admitting it used generative AI to help produce it. According to the Guardian, the errors included nonexistent references and citations. Another paper reported a made-up reference to a court decision in a robodebt case.

None of these errors shows on the surface of a draft. You find them by opening the source.

Why does a wrong fact cost more in AI answers?

An AI answer squeezes your page into a few sentences, and the engines already make mistakes with sources they read. If you publish an error yourself, that's the version they repeat, next to your name.

The Tow Center for Digital Journalism tested eight AI search tools for Columbia Journalism Review, running sixteen hundred queries in a test published in March 2025. Collectively, the tools gave incorrect answers to more than 60 percent of queries, the Tow Center found.

Error rates in that test ranged from 37 percent of queries for Perplexity to 94 percent for Grok 3. Gemini and Grok 3 often cited fabricated or broken URLs that led to error pages, the Tow Center reported.

In a study by the European Broadcasting Union and the BBC, published in October 2025, journalists evaluated more than 3,000 responses from ChatGPT, Copilot, Gemini and Perplexity. The EBU and BBC study found 31% of responses showed serious sourcing problems: missing, misleading or incorrect attributions.

The same research found that when many people see errors in AI news summaries, they blame news providers as well as AI developers. We'd expect brands to get the same treatment, and if the error started on the brand's own page, readers would be right to blame it.

What should you check in every article?

Every type of claim that can be wrong needs a check, including the ones that never appear in the visible text. Quotes, statistics and links get their own how-to below.

How do you check a quote word for word?

The words have to appear on the original page, with the same speaker, date and meaning as in your draft.

1. Find where the words first appeared. A transcript, court filing, paper, press release or the speaker's own post. A page that quotes the quote doesn't count.
2. Search the exact wording on that page. If find-in-page can't locate it, read the passage: the draft may have paraphrased the line or merged sentences.
3. Match the speaker, title and date. A quote from a former role needs the former title.
4. Keep cuts honest. Use an ellipsis only where the original sentence carries on, and never cut in a way that changes the meaning.
5. Verify academic references in full. Winston AI's guide to checking AI output says to verify author names, publication titles, journal authenticity and DOIs.
6. Trace the claim to its origin. Google's guidelines for fact-check publishers require each checked claim to be attributed to a distinct origin separate from your website, with analysis that cites primary sources.

Quotes that circulate widely deserve the most suspicion. Winston AI's guide notes that a line attributed to Voltaire was written by Evelyn Beatrice Hall in 1906. If you can't find where a quote started, leave it out.

How do you verify a statistic before you publish it?

Go to the study or dataset that measured the number, and copy the figure with its period, sample and range.

• Cite the study that measured it. A figure passed through roundups loses its method and date. Google's spam policies list republishing other sites' content without adding value "or even citing the original source" as scraping abuse.
• Keep the range. Publish both ends and the measure they belong to, as with the GEO figures above. A range cut to its top end overstates the result.
• State the period and who was measured. Pew's click figures above come from Google searches. They don't tell you how another engine behaves.
• Check the unit and the base. Percent and percentage points differ. Ask what the number is a share of: Pew's in-summary click rate counts only visits to pages that showed an AI summary.
• Look past a fresh date. A page updated this year can carry an old figure. Google's self-assessment asks whether sites change page dates to seem fresh when the content has not substantially changed.

How do you check sources and links?

Open every link and read the page it lands on: it should be the original, it should load, and it should say what your sentence claims. The Tow Center's broken-URL findings above show why.

• Link the publisher's own page. The Tow Center also found generative search tools cited syndicated and copied versions of articles.
• Name the source in the sentence. Contently's guide to AI Overviews advises citing recognized sources, naming them in the text and linking out so the claim is verifiable.
• Check papers for retractions. Crossref acquired the Retraction Watch database in September 2023 and made it publicly available.
• Open every citation an assistant gives you. OpenAI's ChatGPT search help page says results and citations can be incomplete, outdated or incorrect, and tells users to open a cited source to check it supports the answer.

What else on the page needs checking?

Readers rarely see these parts, but search engines read them. Google's guidance on AI-generated content says the same accuracy review applies to metadata such as meta descriptions, structured data and image alt text, which can appear in Search results.

• Structured data that matches the page. Google's AI features guidance includes making sure structured data matches the visible text on the page.
• Labeled, consistent dates. Google's publication-date guidance asks for a prominent, user-visible date labeled with text like "Publish" or "Last updated", matching the dates in structured data.
• Real authors. Google calls fabricated creator profiles, such as AI-generated headshots, made-up names or false credentials, a form of deception.
• How AI was used. Google suggests telling readers how automatically generated content was created, in a way that makes sense for your audience.

How we tested this question

In October 2026, as our engine check before writing, we asked ChatGPT and Claude this page's main question with web search available. Both answered from what they already knew, without searching.

We then asked a more specific version, about the process and tools for checking quotes, statistics and sources in articles meant for ChatGPT and Google AI Overviews, and both searched. ChatGPT went to official documentation (Google Search Central, OpenAI's help pages, Crossref, the Internet Archive) and public data portals, while Claude cited vendor blogs and tool round-ups. Neither named OnlyAEO.

So the specific question is where the pages an engine finds decide the answer, and that's where your page has to hold up.

Which tools help, and what can't they do?

Tools can surface claims someone has already checked and links that no longer work. None of them can confirm a new claim on your page.

• Google Fact Check Explorer. Feedough's review of fact-checking tools notes that Explorer only returns claims a participating organization has already checked, and only from organizations using ClaimReview markup. Google is phasing ClaimReview out of Search while keeping it in Fact Check Explorer.
• AI fact-checking assistants. Use them to list claims worth checking. Their verdicts carry the same risk as the legal tools and ChatGPT citations above.
• SEO and AI visibility tools. Google's AI optimization guide says no third-party tool has access to its internal ranking or AI systems. Read their reports as estimates.
• Schema plugins. The same guide says structured data isn't required for generative AI search and there's no special schema.org markup to add.

Who should sign off before it goes live?

A named editor who did not write the draft should sign off, and their decision to hold a page should stand.

Google's helpful content guidance suggests having others you trust but who are unaffiliated with your site give an honest assessment of your content. The same guidance says informational pages should be factually accurate, and that on topics that could significantly affect people's lives or well-being, content must be highly accurate.

Signing makes that person answerable for the page. In the Mata v. Avianca sanctions decision, the judge wrote that existing rules impose a gatekeeping role on attorneys to ensure the accuracy of their filings. On your site, that gate belongs to the editor.

Plan for the error that still gets through. Google requires fact-check publishers to have a corrections policy or a way for users to report errors, and a corrections note with a contact address does the same job on any site.

What to ask a writer or vendor about fact-checking

If someone outside your team writes or checks your content, ask:

• Who checks? A named person other than the writer, and what they know about the subject.
• Against what? The source page itself, or someone's summary of it.
• What stops a page going live? Which failed check holds it, and who can overrule that.
• How do corrections work? How fast a reported error gets fixed, and whether the fix is noted on the page.

For a longer list of questions to put to any AEO agency or vendor, use our AEO RFP template.

How do you check what AI engines say after it goes live?

Ask the engines your page's question, open the sources they cite, and compare their answer with your page. Fix your page when the answer drifts from the facts.

1. Ask the page's main question in each engine your buyers use, with web search on.
2. Open what the answer cites. Note whether your page is among the sources and what each cited page says.
3. Compare the claims. Where the answer states a fact differently from your page, find the cited page it came from.
4. Fix the source you control. Correct your page if it's wrong; if an outside page is wrong, ask that site for a correction.

For a full method across engines, see our guide to running an AI visibility audit.

Where does OnlyAEO fit?

OnlyAEO is the AEO platform that tracks where ChatGPT, Claude and Gemini name your brand and creates the content to change it. Our team can also run it for you.

Our content engine checks every quote word for word against its source page and every number against an evidence row, and a claim it cannot support is cut before a draft moves on. That's the check this page describes, run on every draft.

Your own team can run the same checks by hand with the table above. If you'd like to see where you stand first, a free AI visibility audit, delivered within 48 hours, shows how the engines describe your brand today.

More questions about fact-checking content for AI search

Does Google penalize content because AI wrote it?

Google draws the line at purpose and oversight. It says using automation, including AI generation, mainly to manipulate search rankings violates its spam policies, and that producing large amounts of AI text without manual oversight or curation represents little to no effort.

Can publishing many AI-written pages count as spam?

It can. Google warns that using generative AI to generate many pages without adding value for users may violate its spam policy on scaled content abuse.

Do citations alone make a page trustworthy?

Google says attribution or giving credit to other sources doesn't replace the need for original effort.

Does keyword stuffing help a page show up in AI answers?

The GEO study found keyword stuffing offered little to no improvement in generative engine responses. Citing sources, by contrast, raised visibility by 115.1% for websites ranked fifth in search results.

Which quality signal does Google weigh most?

Trust. Of the E-E-A-T aspects, Google says trust is most important, and its self-assessment for content asks whether a page has any easily verified factual errors.