For writers and researchers who work with AI
Every claim, accounted for.
Eustace turns your drafts into an auditable claim ledger. It extracts the factual claims, you approve which ones matter, and it verifies each against independent evidence — sources cited, uncertainty stated, nothing hidden.
25 claim verifications free. No card required.
| Claim | Verdict | Sources |
|---|---|---|
| The Amazon produces about 20% of the world’s oxygen. | Contradicted· high | 3 cited |
| The Kyoto Protocol was adopted in December 1997. | Verified· high | 4 cited |
| Remote work increased regional median rents by 12%. | Needs user source· low | 1 cited |
Ten verdicts, three confidence levels, every source on the record — never a bare “true/false.”
How it works
Add a document
Paste text, or import from a URL, PDF, or Word file. Scanned PDFs are OCR'd automatically.
Eustace extracts claims
Candidate factual claims are pulled out with their original quotes, block by block.
You approve the queue
A human checkpoint before anything expensive runs. Queue the claims worth checking; skip the rest.
Independent verification
Each claim is checked against fresh web sources — never against your own document.
Inspect and override
Read every source, attach private evidence, and overrule a verdict — the machine's call stays on the record.
Export the audit
A Markdown fact-check report with claims, verdicts, confidence, and citations.
Audit trail over magic
Every verdict carries its sources and reasoning. You can retrace each check, months later.
You stay the editor
Nothing is verified without your say-so, and your overrides are first-class — recorded alongside the machine’s verdict.
No false precision
When the evidence is thin or mixed, Eustace says so instead of rounding to “true.”
Pricing
Free covers casual fact-checks; Pro is for working writers and researchers.
Free
$0 — no card required
- 25 claim verifications, yours to spend anytime
- Unlimited projects and documents
- Full ledger, overrides, and Markdown reports
Pro
$19/month, or $180/year
- 500 claim verifications every month
- Optional overage at $0.05/claim — off by default
- Everything in Free