Mephistopheles — AI fact-check

by mic · mephistopheles.ai · Tools

Established publisherManifest V3 Free

View in Chrome Web Store Data as of 17 Oct 2026

Fact-check any AI answer: a grounded trust score plus the specific claims it got wrong, each with a real source.

Users

0 in 30 days

Rating

0.0 / 5

unchanged in 30 days

Ratings

0 in 30 days

Store rank

#304K

#247K among extensions

Version

1.0.0

updated 21 Jul 2026

Users

monthly, 3 months

Latest, 17 Oct 2026: 3 usersMove the mouse over the chart for any month

Ratings count

monthly, 3 months

Latest, 17 Oct 2026: 0 ratingsMove the mouse over the chart for any month

The Chrome Web Store rounds user counts down to the leading digit, so the user line moves in steps. The ratings count is exact and is the better signal of real adoption.

About Mephistopheles — AI fact-check

Don't take an AI's word for it — check it. Mephistopheles is the accuracy layer for any AI. Highlight an answer from ChatGPT, Claude, Gemini — or any text on any page — right-click "Verify with Mephistopheles," and get an instant, grounded fact-check: a hallucination-risk score plus the specific claims the model got wrong, each with the source that contradicts it. How it works: it pulls out each factual claim, checks each one against independent sources (live web search, Wikipedia, Wikidata), and returns a per-claim verdict — supported, contradicted, disputed, or unverifiable. It flags what it can't confirm instead of guessing, so you know exactly what to trust and what to double-check. • Works on any site — ChatGPT, Claude, Gemini, or anything you're reading • Right-click to verify a selection, or click the toolbar icon and paste • Cited, not guessed — every flag points to real evidence • Nothing is stored — the text you check is used only to produce the result Free to try. For heavier use, sign in at mephistopheles.ai.