AAddSub
ENJA
100% on-device · macOS 26 · Apple Silicon

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 credit card · one-time license

▶ A talk about on-device AI — YouTube
S1

"…and the entire model runs locally on Apple Silicon."

S2

"Wow — so no audio ever leaves the device?"

S1

"まったく、すべてオンデバイスで処理されます。" · "Exactly — it all runs on-device."

Live · EN ⇄ JA
99
languages supported
100%
on-device processing
0
cloud fees, ever
7 days
free trial, no card
Why AddSub

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
Whisper-class 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.
Vision OCR
On-screen text — slides, code, UI — is read and interleaved with the transcript. Great for lectures, demos, and tutorials.
Floating glass overlay
A gorgeous Liquid-Glass HUD floats above any app: browsers, video players, meetings, full-screen content. Always on top, always readable.
How it works

From video to subtitles in three steps

1

Play anything

Play any video, stream, or call through your Mac — a browser, player, or meeting app.

2

AddSub listens

AddSub taps the audio locally and transcribes + translates it in real time on your Neural Engine.

3

Read captions

Live, translated subtitles float above the content with speaker labels — copy them or export to SRT.

99 languages

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:

English日本語EspañolFrançaisDeutsch中文한국어PortuguêsItalianoРусскийالعربيةहिन्दीBahasa IndonesiaไทยTürkçeTiếng ViệtNederlandsPolskiУкраїнськаעבריתΕλληνικάSvenskaDanskNorsk+79 more →
Your audio stays yours

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.

FAQ

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 (whisper-class), translation (Apple Translation), and OCR 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 credit card required. 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.