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Preview of Video Justifier

Video Justifier by Mischa

Justify videos to the left or right in theatre/fullscreen mode.

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Extension Metadata

About this extension
A lightweight Firefox extension designed mainly for multi-monitor setups. When a video is playing in theatre mode or fullscreen mode, this extension allows you to shift the video frame to the left or right, rather than the default centre, replacing the default black bars. This is done by overriding the site's default CSS positioning rules, foregoing the need for complex JavaScript tracking.

Supported Platforms
  • YouTube
  • Twitch.tv
  • Kick.com

Usage

You can justify the video using either the extension popup menu or with the following keybinds:
  • Justify Left: Ctrl + Alt + Left Arrow
  • Justify Centre: Ctrl + Alt + Down Arrow
  • Justify Right: Ctrl + Alt + Right Arrow

(Note: Keybinds can be changed in the Firefox Add-ons manager under the gear icon > "Manage Extension Shortcuts").
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Permissions and data

Required permissions:

  • Access your data for sites in the youtube.com domain
  • Access your data for sites in the twitch.tv domain
  • Access your data for sites in the kick.com domain

Optional permissions:

  • Access your data for sites in the youtube.com domain
  • Access your data for sites in the twitch.tv domain
  • Access your data for sites in the kick.com domain

Data collection:

  • The developer says this extension doesn't require data collection.
Learn more
More information
Add-on Links
  • Support site
Version
1.0
Size
11.25 KB
Last updated
25 days ago (Feb 24, 2026)
Related Categories
  • Appearance
  • Photos, Music & Videos
License
GNU General Public License v3.0 only
Version History
  • See all versions
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