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Preview of Marfondo Subtitles

Marfondo Subtitles by Marfondo

Interactive language-learning subtitles on YouTube, Netflix, Crunchyroll, and any video site — synced with your Marfondo account.

Available on Firefox for Android™Available on Firefox for Android™
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Extension Metadata

Screenshots
Transcript exampleDictionary lookup exampleAutomatic time tracking dashboardSRS Card example created from Youtube content
About this extension
Learn a language from the shows and videos you already watch.

Marfondo Subtitles adds interactive subtitles to YouTube, Netflix, Crunchyroll, and other video sites. Click any word to see its meaning, mark words as known or unknown, and save them to your Marfondo vocabulary — all without leaving the video.

• Clickable subtitles: tap any word for a definition and translation
• Two lines at once: your study language, with a translation in your native language underneath
• Full transcript panel: every line of the video, click to jump to it
• Keyboard shortcuts: step line by line (A / D), mark words with 1, 3, 4
• Drag the subtitles anywhere on the player; your position is remembered
• Tracks your study time, and only counts videos recorded in your study language
• Works on YouTube, Netflix, and Crunchyroll out of the box; turn it on for other video sites with one click
• Everything syncs with your Marfondo account and the Marfondo web app

Requires a Marfondo account (marfondo.com). [Free / Pro line — see below]

Marfondo is not affiliated with YouTube, Netflix, Crunchyroll, or any other video service.
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Permissions and data

Required permissions:

  • Access your data for sites in the netflix.com domain
  • Access your data for sites in the youtube.com domain
  • Access your data for marfondo.com

Optional permissions:

  • Access your data for sites in the youtube.com domain
  • Access your data for sites in the netflix.com domain
  • Access your data for sites in the nflxvideo.net domain
  • Access your data for sites in the nflxso.net domain
  • Access your data for marfondo.com

Required data collection, according to the developer:

  • Browsing activity
  • Website activity
  • Website content
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More information
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Version
0.2.4
Size
107.87 KB
Last updated
6 hours ago (Nov 2, 2026)
Related Categories
  • Other
License
All Rights Reserved
Version History
  • See all versions
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