Check an answer

For anyone who relies on AI answers

The AI gave you an answer. Velydian checks it.

Paste an answer from ChatGPT, Claude, Gemini, Perplexity or NotebookLM. Velydian opens the sources it cites, finds sources for the claims it does not, and tells you which sentences hold up.

Check an answer See what it catches

Free trial, no card needed.

  • Cited or not. Every claim checked, and stronger sources found where the evidence is weak.
  • A record you can keep. Annotated document, audit trail and exports, in minutes.
  • Swiss and private. Data residency in Switzerland, processing in Switzerland and the EU, GDPR compliant.
VerdictIllustration
CLAIM IN YOUR ANSWERNeeds Revision

“Some 3,000 individual reef systems and more than 1,500 tropical islands.”

What the source says
“It comprises of 3,000 individual reef systems, 760 fringing reefs, 900 tropical islands and about 300 coral cays.”

wwf.org.au, Great Barrier Reef

The reef systems match. The source counts 900 tropical islands, not more than 1,500.

Illustration of a verdict.

The stakes

What an unsupported claim costs.

45%

AI assistant answers about the news with at least one significant issue, judged by journalists from 22 public service media organisations in 18 countries.

EBU & BBC (2025), News Integrity in AI Assistants
66%

Workers who say they rely on AI output without evaluating its accuracy. 56% say they have made mistakes in their work because of AI.

KPMG & University of Melbourne (2025), Trust in AI global study
60%+

News excerpts that eight AI search tools attributed incorrectly when asked to name the source, across 1,600 queries.

Columbia Journalism Review, Tow Center (2025)

What it catches

Six things that go wrong in AI answers.

Each one with the claim, the passage Velydian reads, and the verdict. Examples for illustration.

A number that drifted

“The study followed 12,000 patients.”

“A total of 1,200 patients were enrolled.”
Needs Revision

The source enrolled 1,200 patients. The answer adds a zero.

A citation that leads nowhere

“According to Harvard Business Review (2023), 70% of transformations fail.”

No article matching this title, year and figure could be found.
Unverifiable

The cited article could not be found. The figure may still exist elsewhere, but not where the answer says.

A source that says something else

“The WHO recommends eight glasses of water a day.”

“Fluid needs vary with age, activity and climate.”
Not Supported

The cited page gives no fixed number of glasses.

A real link, a different claim

“The EU AI Act bans all facial recognition in public.”

“Real-time remote biometric identification in public spaces is prohibited except in narrowly defined situations.”
Needs Revision

The ban has listed exceptions. The answer states it as absolute.

A claim with no source at all

“Most surveyed companies use AI in at least one function.”

Found: a 2025 industry survey reporting AI use in at least one business function by a majority of respondents.
Supported

No source was cited. Velydian found one that backs the claim and shows it.

Old information stated as current

“The current interest rate is 1.75%.”

“The policy rate is lowered to 1.0%.” (later announcement)
Needs Revision

The figure was correct once. A later announcement changed it.

Not another fact checker

Not just right or wrong. Supported or not.

Velydian checks the facts. It also weighs what an answer does with them: the conclusion it draws and how strongly it states it. A number can be real and the sentence around it can still mislead you.

One claim, three levels · illustration“A four-day week raises productivity by 13%, a university study found.”Needs RevisionSource: the study the AI answer cites. Example for illustration.
  1. Level 1

    Facts

    Figures, dates, names and quotations, checked against what the source actually says.

    Does the study say 13% or 1.3%?

    Velydian findsSupportedThe 13% is in the study’s results.A citation check stops here: true.
  2. Level 2

    Interpretation

    Whether a conclusion follows from the source, or reaches further than it.

    Did the study measure this, or something narrower?

    Velydian findsStretchedThe study measured calls handled per shift in one call centre. The answer states it for work in general.
  3. Level 3

    Judgement

    Whether the statement is as strong as its evidence, and what was left out.

    Would you repeat this to a client as it stands?

    Velydian findsOverstatedThe study’s own authors report that the gain shrank in the second year. The answer leaves it out.Verdict: Needs Revision. The number is real; the answer makes it say more than the study did.

How it works

Paste the answer. Every sentence comes back with its evidence.

Paste an answer from any AI assistant, or upload it as PDF, Word, text or Markdown. Velydian finds each claim and checks it in one of three ways.

Against the sources it cites

When the answer links a page or names a paper, Velydian opens it and checks whether it says what the answer says.

Claims with no source

Velydian searches official websites, research databases and the wider web, keeps the strongest sources and checks the claim against them.

Against your own files

Attach the document the AI summarised, such as a report, a contract or meeting notes, and every sentence is checked against it. You see the price before it starts.

Three layers of checking

Surface tools check that a source exists. Velydian reads it.

Layer 1

Distortions and inaccuracies

Numbers that drift, dates that shift, a quotation reworded.

An answer that adds a zero to a sample size.

Layer 2

Bias and fabrication

Sources that do not exist, a source that says something else, and what was left out.

A cited article that cannot be found anywhere.

Layer 3

Stronger sources

When a claim rests on a weak source, Velydian looks for a more authoritative one.

A blog post is flagged, with the study behind it offered instead.

One verdict per claim

Four verdicts, each with its evidence.

Supported

The source checked backs the sentence as written.

Needs Revision

Close, but a number, a date or the strength of the statement does not match the source.

Not Supported

The source does not back the sentence, or says something different.

Unverifiable

No source could be read or found that settles it, for example a dead link or a reference that does not exist.

Open any verdict to see the passage and the reasoning behind it. Correct a line or swap a source and it is checked again. Velydian weighs the evidence; you decide what to keep.

  1. Paste the answerOr upload PDF, DOCX, TXT or MD.
  2. Every sentence is checkedAgainst the cited source, your own files or independent sources.
  3. Review and correctFix a sentence or swap a source; it re-checks.
  4. Take the resultAnnotated answer, evidence, executive summary, CSV/JSON exports.

How we test it

Test it on a document you already know.

Our published test results so far are on company reports: see Velydian for Finance. For every other kind of document, the best test is one of your own.

Every verdict, open to inspectionSource + reasonEach verdict shows the passage it rests on and why, so you can check Velydian itself.In every result
When the sources cannot settle itUnverifiableThe claim is marked Unverifiable, with the reason, for a person to check.One of four verdicts
Your own testYour documentRun an answer where you already know the mistakes, and see whether Velydian finds them.First check free

Review the verdict and the reasoning yourself: every one shows its evidence. Your first check is free.

Today and with Velydian

From hours of checking to minutes.

Checking AI answers by hand

Clicking every link, hoping

  • Each cited link opened and read by hand
  • Claims without a source are taken on trust
  • Invented references look exactly like real ones
  • Nothing to show for how the answer was checked
Velydian on AI answers

Every sentence checked

  • The whole answer checked in minutes
  • Every cited source we can reach is read; the rest are flagged
  • Sources found for the claims that had none
  • The passage behind every verdict, ready to share

What it checks

The documents your team signs.

  • ChatGPT answers
  • Claude answers
  • Gemini answers
  • Perplexity answers with their sources
  • NotebookLM notes
  • AI-drafted emails, memos and summaries
  • Deep-research reports
  • Any pasted text

Who uses it

Across the team.

  • ProfessionalsCheck an AI answer before it goes into a memo, a slide or an email.
  • Team leadsGive the team one way to check AI output before it reaches a client.
  • Students and researchersSee which claims in an AI summary the literature really supports.
  • Anyone curiousFind out where an answer came from, and whether the source says it.

What you get back

A record you can keep.

  • The annotated answerEvery sentence marked with its verdict, in place.
  • The evidenceFor each claim, the passage that backs it or contradicts it.
  • Better sourcesWhere the answer cites a weak source, a stronger one to use instead.
  • ExportsExecutive summary, CSV and JSON.

Cost

You see the price before you start.

Checking an answer by handCHF 150your rate × your hours
With Velydian, pay as you goCHF 4.8031× cheaper30 cited claims drawn from 10 sources: 160 credits
At the Founder rateCHF 1.6094× cheaperthe same answer, CHF 0.01 per credit

Checking a claim costs 5 credits and reading a source costs 1. Deeper source audits cost more. Your reviewers still read the verdicts; Velydian takes the tracing off their desk.

Questions

Before your first answer.

Do I need the Chrome extension?

No. Paste or upload any AI answer today. The extension sends the answer and its sources over in one click from ChatGPT, Claude, Gemini, Perplexity, NotebookLM and Google AI Mode; it is coming to the Chrome Web Store.

What if the answer cites no sources?

Velydian searches official websites, research papers and the wider web for each claim, keeps the strongest sources and checks the claim against them.

Which AI assistant is most accurate?

Velydian does not rank assistants. It checks the answer in front of you, whichever assistant wrote it.

Can it check a long deep-research report?

Yes. Upload it as PDF or Word, or paste the text, and every claim in it is checked.

Where do the sources come from?

Three places. The sources your document cites; sources Velydian finds on official websites, research databases and the wider web for claims without a citation; or your own files, if you attach them.

What happens to my document?

When you run a check, your document’s text is sent over an encrypted connection to our servers and AI services in Switzerland and the EU. To find evidence, short search queries built from your claims are sent to web and scholarly search services. Your document’s content and results are deleted automatically about 24 hours after your check; source links and summary data are kept.

Which languages does it check?

English is measured and in daily use. German and French are in validation.

Can I rely on Velydian as my only check?

Velydian supports human review. It shows the evidence behind every verdict so you can decide. In high-stakes work, expert judgement stays essential.

A Swiss company

Data in Switzerland. Processing in Switzerland and the EU.

  • Data residency in Switzerland, processing in Switzerland and the EUGDPR and Swiss data protection terms are covered by our Data Processing Agreement.
  • A Swiss companyVelydian is built by MindtheGap Sàrl in Geneva.

Check your next answer before someone else does.

Check an answerHow Velydian works

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