Twinsubs: Bilingual Subtitles
Live translation, on-device
Only for Mac
Free · In‑App Purchases
Mac
Translate any sound on your Mac as it plays, in a caption that floats over what you watch. Works offline. Drop in a video for bilingual subtitles. Nothing is uploaded.
Translate any sound playing on your Mac as it plays, in a caption that floats over whatever you are watching. Drop in a video and a bilingual subtitle file appears beside it.
Twinsubs is a live translation and subtitle tool that runs on your Mac. Recognition and translation happen on this machine: your videos and audio are never uploaded, and there is no account and no API key.
LIVE TRANSLATE
· Most translators put the original on the left and the translation on the right, in a window you have to switch to. Twinsubs stacks the two into a two-line caption that floats over whatever you are watching, so your eyes never leave the video
· Sound playing in your browser, meeting app or player is translated into the language you choose as it plays. Add your microphone and your own speech is marked “Me”
· The spoken language is detected for you, and the caption follows when the language changes
· Works offline: once the language packs are downloaded, no connection is needed
· Expand the transcript to review original and translation side by side, line by line, and save it as TXT or SRT
· Drag the floating window anywhere; font size and opacity are adjustable. Shift-Command-L turns it on and off
BILINGUAL SUBTITLES FOR VIDEO FILES
· Drag videos or audio files into the window, as many as you like; they queue up automatically
· Standard SRT files appear next to each file: a bilingual one (target language on top, original below) and one with the target language only
· One clause per subtitle, short lines, no cuts in the middle of a word; videos in Chinese get punctuated Chinese subtitles
· Import them into CapCut or Final Cut Pro, or load them in players such as IINA
YOUR LANGUAGES
· The source language is detected automatically, or you can pick it; you choose the target language
· Translation uses the on-device translation built into macOS. Available language pairs depend on what the system supports, and macOS asks you to download a language pack the first time you use a pair
· The interface is available in Simplified Chinese, Traditional Chinese, English, Japanese and Korean
GOOD TO KNOW
· The first launch downloads a speech recognition model once (under 1 GB)
· Free use processes the first 10 minutes of each video and 10 minutes of live translation per day; a one-time purchase removes the limits, with no subscription
· Requires macOS 26 or later on a Mac with Apple silicon
· Live translation appears on your own screen; it does not speak for you
· Speech recognition and machine translation make mistakes, so please proofread before publishing, especially with heavy accents or noisy audio
· It does not burn subtitles into video, include a video editor, or tell speakers apart
Questions and feedback: twinsub@gatheon.com
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
The developer, 江 吴, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Linked to You
The following data may be collected but it is not linked to your identity:
- Identifiers
- Usage Data
- Diagnostics
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- 江 吴
- Size
- 3.9 MB
- Category
- Photo & Video
- Compatibility
Requires macOS 26.0 or later and a Mac with Apple M1 chip or later.
- Mac
Requires macOS 26.0 or later and a Mac with Apple M1 chip or later.
- Mac
- Languages
English and 4 more
- English, Japanese, Korean, Simplified Chinese, Traditional Chinese
- Age Rating
4+
- 4+
- In-App Purchases
Yes
- Unlock Full Length $19.99
- Copyright
- © 2026 Gatheon