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Swiftin vs Language Reactor

Language Reactor is the Netflix and YouTube study tool, with a dictionary popup and a smooth Anki export. Swiftin gives you dual subtitles and an AI word card on YouTube, Coursera and Netflix, with real AI on the free plan, and also translates the rest of your web, your PDFs, and what you type.

FeatureSwiftinLanguage Reactor
Dual subtitles on Netflix & YouTube
Dual subtitles on Coursera lectures
Click a word for meaning + examples
AI word card (definition, synonyms, CEFR level)Pro / Lexa AI
Translation engine6 AI models + your own keyMachine translation
Download subtitles & transcriptSRT, VTT, TXT
Export words to Anki flashcards
Translate any live webpage (bilingual)
Translate PDF, EPUB & Word docs
Translate what you type + writing tools
AI text-to-speech70+ languagesReader only
Languages supported100+~27
Real AI on the free tierPro
Firefox support

Language Reactor details from its Chrome Web Store listing and languagereactor.com, June 2026. Some features (full machine translation, unlimited word saving, Anki export) are on its Pro plan.

Why Swiftin

Subtitles beyond Netflix and YouTube

Language Reactor lives on Netflix and YouTube. Swiftin adds Coursera, so university lectures and online courses get the same dual subtitles and the same click-to-define word card, not just movies and clips. You learn from the content you actually study, not only the content you watch for fun.

An AI word card, not just a dictionary popup

Click any word in a subtitle and Swiftin builds a small lesson on the spot: the meaning in context, usage examples, synonyms and antonyms, the part of speech, a CEFR difficulty badge, and a button that reads the word and the example out loud. No Anki pipeline to set up. Language Reactor shows a dictionary lookup on free; its richer AI dictionary and full word saving sit behind Pro.

It is not only subtitles

Subtitles are one surface. Swiftin also translates any live webpage side by side, translates PDF, EPUB and Word documents with the layout intact, and translates what you type in any input field with writing tools to fix grammar and change tone. Language Reactor reads imported text and ebooks in its own reader, but it does not translate arbitrary live pages, PDFs, or the box you are typing into. One extension instead of three.

Real AI on the free tier

Swiftin lets you pick the AI model behind your translations and word cards: Claude, GPT, Gemini and more, or bring your own key. The free plan includes 50,000 AI tokens a month plus unlimited Google and Bing translation that takes over automatically when the AI quota is spent, so it never goes silent mid-sentence. Language Reactor's core subtitle translation is machine translation, and its full translation and saving features are Pro.

Chrome and Firefox

Swiftin ships a Chrome build (which also runs on Edge, Brave, Arc and Opera) and a real Firefox build. Language Reactor is Chrome and Edge only. Neither tool runs on mobile browsers: both are desktop extensions.

Swiftin is better if you...

  • Want dual subtitles on Coursera lectures, not just Netflix and YouTube
  • Want an AI word card with examples and synonyms on the free plan, no Anki setup
  • Want one tool that also translates your webpages, PDFs and what you type
  • Want to choose the AI model instead of plain machine translation
  • Use Firefox, or want a free plan whose translation never runs out

Language Reactor is better if you...

  • Live inside Anki and want the smoothest subtitle-to-flashcard export
  • Want a study tool built around spaced repetition and phrase drills
  • Only ever study on Netflix and YouTube and need nothing off-video

Try Swiftin free

Install in 30 seconds. Free includes dual subtitles, the AI word card, 50,000 AI tokens per month, and unlimited Google and Bing fallback. No card required.