Lenz — Audit-grade AI Fact-Checking API

Audit-grade fact-checking for AI products that can't afford to hallucinate.

Eight models across five stages, grounded in real sources. Opposing-side debate, three independent reviewers, full citation trail.

Build with the API &rarr;<br>See an example verification &rarr;

Just want to check one claim? Verify a single claim instead &rarr;

Independent multi-vendor LLM pipeline·OpenAPI 3.1·Cited by ChatGPT, Perplexity, Gemini

For AI product teams

Four API primitives form a depth ladder:

/extract<br>Pull verifiable claims out of any text

/assess<br>Fast multi-model verdict for sync UX

/verify<br>Full adversarial pipeline with citations

/ask<br>Follow-up Q&A grounded on a verification

Used for<br>incident triage · async runtime verification · pre-release CI

Start with the API &rarr;

For anyone with a claim

Paste a statement, link, or question. Get a sourced verdict with the reasoning shown — not just an answer.

Example<br>&ldquo;Failure by police to read Miranda rights does not invalidate an arrest.&rdquo;

Verify a claim &rarr;<br>Open the research workbench &rarr;

Research

Beyond Benchmarks: Disagreement Among Frontier LLMs on Real-World Fact-Checks

Open evaluation of frontier LLM agreement on user-submitted claims. Frozen snapshots, full data, full methodology.

Read the report &rarr;

Library

Developers

Account

More

{ if(a&&!a.target){ if(a.pathname===location.pathname){$event.preventDefault();overlay=null;if(history.state&&history.state._overlay)history.replaceState({},'',location.href)}else{$event.preventDefault();location.href=a.href} }})($event.target.closest('a[href]'))">

Account

✉️

Enter the 6-digit code

We sent it to .

Expires in 15 minutes.

✓ New code sent

Didn't get it? 0" x-text="resending ? 'Sending...' : (resendCooldown > 0 ? 'Resend in ' + resendCooldown + 's' : 'Resend')">

Use a different email

{ try { $refs.codeInput.focus(); } catch(e) {} }, 100)">Open mail app

Can't access your email?

Sign in with Google

Sign up to verify claims

Verify claims, save your results, watch for updates, and view your history.

Continue with Google

or

By continuing, you agree to our<br>Terms of use and Privacy policy.

{ if(a&&!a.target){ if(a.pathname===location.pathname){$event.preventDefault();overlay=null;if(history.state&&history.state._overlay)history.replaceState({},'',location.href)}else{$event.preventDefault();location.href=a.href} }})($event.target.closest('a[href]'))">

More

Research

Install App

WhatsApp

Appearance

About

About

How it works

Pricing

Contact

Terms

Privacy

Cookie settings

Lenz uses cookies for analytics and ads. See our privacy policy.

Decline<br>Accept