Subtitles for anything you watch
AddSub overlays live, translated subtitles on any video, call, or screen — in 99 languages, with speaker labels, fully private. Free to try for 7 days.
7-day free trial · no payment needed to start · one-time license
「本日はオンデバイスAIの最新アーキテクチャについてご説明します。」
"Today,"
Everything you need to watch anything, understood
Built for people who watch foreign films, follow global news, study with lectures, or run international meetings — and want it all captioned in real time.
Real-time transcription
On-device neural speech recognition runs on your Mac's Neural Engine — subtitles appear as you watch, with no cloud round-trip.
Live translation, 99 languages
Watch content in any of 99 languages and read it in yours. Japanese, English, Spanish, Chinese, and everything in between.
Speaker diarization
Who said what? AddSub identifies speakers with color-coded badges (S1, S2, S3…) as they talk — perfect for interviews and podcasts.
100% on-device privacy
Audio never leaves your Mac. No servers, no uploads, no subscriptions eating your data. Everything runs locally on Apple Silicon.
Floating glass overlay
A gorgeous Liquid-Glass HUD floats above any app: browsers, video players, meetings, full-screen content. Always on top, always readable.
AI transcript summarization
Condense long meetings, lectures, and foreign videos into structured key takeaways in one click using Apple Intelligence on-device models.
From video to subtitles in three steps
Play anything
Play any video, stream, or call through your Mac — a browser, player, or meeting app.
AddSub listens
AddSub taps the audio locally and transcribes + translates it in real time on your Neural Engine.
Read captions
Live, translated subtitles float above the content with speaker labels — copy them or export to SRT.
Speak any language. Understand all of them.
Transcription and translation across 99 languages — auto-detected or pinned to a language pair. Here's a taste:
No servers. No uploads. No subscription tracking you.
AddSub is a single native app that runs entirely on your Mac. Your conversations, lectures, and videos are processed on-device by the Neural Engine — nothing is sent to the cloud, and there are no per-minute API fees. It's both the private choice and the cost-free one.
Frequently asked questions
Does AddSub work with any video or app?
Yes. AddSub taps the audio of any app playing through your Mac — browsers, video players, meetings, live streams, presentations. The subtitle overlay floats above everything, so it works with Netflix, YouTube, Zoom, PowerPoint, and more.
Is my audio uploaded anywhere?
No. Everything runs 100% on-device. Speech recognition, translation, and speaker diarization all use your Mac's Neural Engine. Nothing is sent to a server.
Which languages does AddSub support?
Speech recognition covers 99 languages, and translation can convert between any of them. You can pick a language pair (e.g. Japanese → English) or let AddSub auto-detect what's being spoken.
What are the system requirements?
macOS 26+ on Apple Silicon (M1 or newer). AddSub is fully native and takes advantage of the Neural Engine for fast, low-power transcription.
How does the 7-day trial work?
Download AddSub, launch it, and you get the full app for 7 days — no payment needed to start. After the trial, activate a one-time license to keep using it.
Read anything. Watch everything.
Install AddSub in under a minute and get live translated subtitles on anything you watch.