Eustace vs Omniscient AI

Eustace is a web-based fact-checking workspace for writers and researchers working with AI-assisted drafts. 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 displays their original quotes so users can select which to verify. Approved claims are checked against fresh web sources rather than the submitted document. Its ledger uses ten verdicts and three confidence levels, and the product says it signals uncertainty when evidence is thin or mixed. Users can inspect sources, attach private evidence, override a verdict with the change recorded, and export a Markdown report with claims, verdicts, confidence, and citations. Eustace says it does not sell user data or use documents to train AI models. The Free plan provides 25 lifetime verifications; Pro costs $19/month for 500 each month, with optional $0.05-per-claim overage turned off by default. Automated verdicts, confidence labels, and summaries can be wrong, incomplete, or out of date, so they are intended to support rather than replace editorial judgment.

Omniscient AI provides source-linked fact-checking through an API, a WordPress plugin, and a Chrome extension. An API response contains a consensus Trust Score, model verdicts, and source citations in structured JSON. Each request runs GPT-4o Mini, Perplexity Sonar Pro, and Gemini 2.5 Flash; the developer page says a consensus result returns in under three seconds. The WordPress plugin can add a Fact-vs-Opinion bar and automatically analyze published articles using the publisher’s API key. In Chrome, users can check a webpage or selected text and view results with supporting sources. Documentation also describes webhook delivery and an OBS browser source. Enterprise API v1 accepts claims up to 8,000 characters and lists ten supported languages. The pricing FAQ presents Trust Scores as a triage aid and recommends human review for high-stakes decisions. The try page offers five free checks after Google sign-in. The free plan has a $0 monthly base, then charges $0.005 per fact-check request; paid monthly plans include Always-On Pro at $399 and Agency at $1,000.