🔎 CaptainFact - Browser Extension. Displays facts on YouTube videos
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Available Available Works with Chrome extension Not yet Not yet

Extension Features

Icon helper

A small icon appears when you're watching a video that has been verified on CaptainFact.io. It tells you, based on votes, if the statement you're hearing (or what is shown) is believed to be true or false.

Icon approve Icon refute

Facts overlay

When clicked, the CaptainFact icon displays facts and comments about current statement and their respective scores.

Demo screenshot


  • Install (if you don't have them):

    • Docker (to start the API easily)
    • Node.js
    • App dependencies: npm install
  • Run:


  • Why do you need storage permissions ?

We store a local cache of videos ids that exist on CaptainFact. This cache gets updated when you visit Youtube if it's older than 15 minutes. This is a privacy improvement that guarantees we don't track the videos you're watching and don't send unnecessary requests.

  • Why do you need tabs permissions ?

Because we inject script programmatically from background (only if video is known from cache) and to be able to disable CaptainFact on all tabs when you unselect it from extension popup.

You can check by yourself in chrome/extension/background.js (look for chrome.tabs.)

  • Why do you need Youtube permissions ?

To be able to inject the facts overlay on Youtube videos.

  • Why do you only inject on youtube.com and not in embedded players everywhere else ?

We may want to implement this in a separate release in the future. We don't want to implement this feature in main extension cause it means asking for permissions to access all your sites.

  • Can I add sources on videos directly from the extension ?

Not at the moment.

Linked projects

Feature requests

Feature Requests


GNU General Public License v3.0

Permissions of this strong copyleft license are conditioned on making available complete source code of licensed works and modifications, which include larger works using a licensed work, under the same license. Copyright and license notices must be preserved. Contributors provide an express grant of patent rights.

See LICENSE for more info.