A Mac app for language learners
Learn languages with YouTube.
Paste a video link and Subline shows the video next to a clean transcript, laid out as a dialogue. The transcript follows the audio word by word, and you can save vocabulary as you watch.
Free for 7 days, no account or card · macOS 13 or later · Which one is my Mac?
Buenas tardes.
Good afternoon.
¿Nos puede traer la carta, por favor?
Could you bring us the menu, please?
Por supuesto.
Of course.
Aquí la tienen.
Here you are.
¡Muchas gracias!
Thank you very much!
¿Podría recomendarnos algún plato especial de la casa?
Could you recommend a house specialty?
Claro que sí.
Certainly.
Nuestro plato estrella es el cochinillo asado, pero también le recomiendo nuestro arroz caldoso con bogavante.
Our signature dish is roast suckling pig, but I also recommend our lobster rice.
Suena delicioso.
Sounds delicious.
Study the videos you actually enjoy
Street interviews, podcasts, cooking shows: if it is on YouTube, it becomes a lesson you can replay sentence by sentence.
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Dialogue transcript
Sentences are punctuated, grouped by speaker and named when possible, with an optional translation line in your language.
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Follows the video
The current sentence and word are highlighted. Click a sentence to replay it, loop it, or pause after each sentence for shadowing practice.
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Folders
Nest folders to any depth (🇪🇸 Spanish › Street interviews › Daily life), give them an emoji, and drag and drop folders and videos.
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Vocabulary
Select words to save them with their sentence and timestamp, then export them to CSV, ready for Anki.
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Claude formats the text
Raw captions become a readable dialogue, in the speakers' own words. Use your Claude app with no API key, or your Anthropic API key.
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All local
Everything is stored as plain files in a folder you control. Export everything writes your transcripts (Markdown) and vocabulary (CSV) to a folder in one click.
Made for the keyboard
- Space
- Play / pause
- ← →
- Previous / next sentence
- R
- Repeat the sentence
- L
- Loop the sentence
- P
- Pause after each sentence
- [ ]
- Slower / faster
- T
- Show / hide the translation
- ⌘K
- Open any video or folder
From a link to a lesson in a minute
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Paste a YouTube link
Pick human captions for the most accurate text or auto-generated ones for exact word timings, or attach your own .srt or .vtt file. A basic transcript is ready in seconds.
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Let Claude format it
Claude adds punctuation, splits sentences, names the speakers and can add a translation line. It only fixes obvious recognition errors and keeps what people actually said.
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Watch, repeat, save words
Click any sentence to play from there, loop the hard parts, slow down, and select words to add them to your vocabulary.
Free for 7 days. No account, no card.
Download Subline and use all of it for a week. The trial runs on your Mac and never goes online. If you like it, buy a license once to keep using it.
Subline license
One-time purchase
- Use it on up to 3 Macs.
- Paste the key from your purchase email into Settings › License.
- New Mac? Deactivate the old one in the app or from your purchases page.
- Your library is always yours: Export my data works even after the trial.
Payment and receipts are handled by Polar, the Subline store.
Your data stays on your Mac
Everything lives in one folder you choose, as plain JSON files. There is no Subline account.
- Back it up by copying the folder.
- Put it in iCloud Drive to share it between Macs, one Mac at a time.
- Your Anthropic API key never leaves the macOS Keychain.
Nothing is sent anywhere except
- YouTube
- for video details, captions and playback.
- Anthropic
- only when you format a video with your API key.
- Your Claude app
- when you ask it to format a video.
- Polar
- when you activate your license and about once a day after that: your license key, your Mac's name and a one-way hash of its hardware id. The trial itself never goes online.
Get Subline
For Apple silicon and Intel Macs with macOS 13 or later.
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Install yt-dlp
The open-source tool Subline uses to read YouTube captions. With Homebrew:
brew install yt-dlp -
Download Subline
Open the disk image and drag Subline to Applications.
Which one is my Mac? Open the Apple menu › About This Mac. If it lists a Chip such as Apple M1 or later, choose Apple silicon. If it lists an Intel Processor, choose Intel.
First launch: Subline isn't notarized by Apple yet, so macOS says it can't verify the app. Click Done, then open System Settings › Privacy & Security and click Open Anyway next to Subline. You do this once per version.
Subline tells you when a new version is out. Download it and drag it to Applications to replace the old one: your library, settings and license stay.