Eustace
Eustace is a web-based fact-checking workspace for writers and researchers working with AI.
What Eustace is
Eustace is a web-based fact-checking workspace for writers and researchers working with AI. Users can paste text or import a URL, PDF, or Word file; scanned PDFs are processed with OCR. The service extracts candidate factual claims and shows each with its original quote so users can choose which ones to verify. Approved claims are checked against fresh web sources rather than against the submitted document. Its ledger uses ten verdicts and three confidence levels, and Eustace says it indicates uncertainty when evidence is limited or mixed. Users can inspect sources, attach private evidence, and override verdicts, with each override recorded. A Markdown report can include claims, verdicts, confidence, and citations. The Free plan costs nothing and provides 25 lifetime claim verifications, unlimited projects and documents, and full ledger, override, and report access. Pro costs $19/mo and includes 500 verifications each month; optional overage costs $0.05 per claim and is off by default. Eustace says documents are not used to train AI models and user data is not sold.
Good
- Accepts text, URLs, PDFs, and Word files.
- OCR processes scanned PDFs automatically.
- Users choose which extracted claims to verify.
- Markdown reports include citations and confidence.
- Overrides are recorded in the ledger.
Watch out
- Free plan is limited to 25 lifetime verifications.
- Pro costs $19/mo for 500 monthly verifications.
- Automated verdicts and summaries can be wrong or outdated.
- AI providers receive document text and claims for processing.
Who it suits
Eustace suits writers and researchers who want to review factual claims in AI-assisted drafts and keep an auditable record of verification. Its Free plan may fit occasional checks, while Pro is described for working writers and researchers.
Verdict
Eustace makes claim review selective and keeps sources, confidence, and overrides together in a ledger. Its automated findings are assistance for editorial judgment, not a substitute for it.
Plans and prices
From Eustace's own pricing page, checked 7 Oct 2026.
| Plan | Price | What it gives you |
|---|---|---|
| Free | Free | 25 claim verifications, yours to spend anytime · Unlimited projects and documents · Full ledger, overrides, and Markdown reports |
| Pro | $19 a month | 500 claim verifications every month · Optional overage at $0.05/claim — off by default · Everything in Free · $19/month |
| Pro | $180 a year | 500 claim verifications every month · Optional overage at $0.05/claim — off by default · Everything in Free · $180/year |
The facts
Each one read from Eustace's own pages, with the date it was checked.
What it does
- AI processing
- The policy says AI model providers receive document text and claims for extraction and verification, while Tavily receives search queries derived from claims rather than the whole document.checked 7 Oct 2026
- Audit and export
- Users can inspect sources, attach private evidence, override verdicts with the override recorded, and export a Markdown report with claims, verdicts, confidence, and citations.checked 7 Oct 2026
- Claim review
- Eustace presents candidate factual claims with their original quotes and lets users approve which claims to queue for verification.checked 7 Oct 2026
- Document input
- Users can paste text or import a URL, PDF, or Word file, and scanned PDFs are OCR'd automatically.checked 7 Oct 2026
- Integrations and processors
- The privacy policy names Supabase, Vercel, Anthropic via Vercel AI Gateway, Tavily, RevenueCat, Stripe, Cloudflare, and Sentry as processors or service providers.checked 7 Oct 2026
- Intended users
- The site describes Free as covering casual fact-checks and Pro as being for working writers and researchers.checked 7 Oct 2026
- Privacy
- Eustace says it does not sell user data or use documents to train AI models.checked 7 Oct 2026
- Purpose
- Eustace is a fact-checking workspace for writers and researchers who work with AI; it extracts factual claims from drafts and checks approved claims against independent evidence.checked 7 Oct 2026
- Security
- The privacy policy says data is encrypted in transit with TLS and at rest by infrastructure providers, production data access is restricted, and database rows are isolated per account.checked 7 Oct 2026
- Service limitation
- Eustace says automated verdicts, confidence labels, and summaries can be wrong, incomplete, or out of date, and are intended to assist editorial judgment.checked 7 Oct 2026
- Support
- The site directs questions and requests to [email protected].checked 7 Oct 2026
- Verdicts
- The ledger uses ten verdicts and three confidence levels, and the product says it reports uncertainty when evidence is thin or mixed.checked 7 Oct 2026
- Verification
- Each approved claim is checked against fresh web sources rather than against the user's own document.checked 7 Oct 2026
- Verification limits
- The free plan has a fixed lifetime allowance of 25 claim verifications; Pro includes 500 per month, with optional overage at $0.05 per claim, off by default.checked 7 Oct 2026
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