Facty

Facty is a browser extension that fact-checks YouTube videos as they play. It reads the video's captions, pulls out claims that can be checked, searches the web and compares independent sources, then shows a verdict card over the player at the relevant moment, with a fuller breakdown in a side report panel.

Verdicts use five levels, from true and mostly true to misleading, false and unverifiable, and each links to up to five sources. The method is a two-source rule: a verdict is given only when independent sources back the claim, otherwise it says unverifiable. Opinions and predictions are flagged rather than argued with, every card has a button to report a wrong verdict, and the videos themselves are not stored. Videos in any language can be checked with verdicts shown in your language, and the site is offered in English, Russian and Spanish.

Facty works in Chrome and Firefox and needs no setup beyond signing in by email or with Google. The site advertises 30 free minutes a month with no card required, with paid options described on its pricing page.