Everything you need to understand anything you watch
Every AddSub feature: real-time transcription, live translation across 99 languages, speaker diarization with color-coded labels, Vision OCR, and a floating Liquid Glass overlay. 100% on-device.
Real-time transcription
AddSub listens to any audio playing on your Mac and transcribes it as it happens. Whisper-class speech recognition runs on the Apple Neural Engine — no cloud round-trip, no per-minute fees, and results appear in under a second.
- Sub-second latency on Apple Silicon
- Whisper-class accuracy (Kotoba-Whisper for Japanese)
- Auto-detect language or pin it manually
- Works with any app that plays audio
Real-time transcription — live on AddSub
Live translation in 99 languages
Watch anything in any language and read it in yours. AddSub detects the source language and translates continuously using Apple's on-device Translation framework.
- 99 speech languages supported
- Language pairs, e.g. Japanese → English
- Bilingual captions (original + translation side by side)
- Apple Translation runs on the Neural Engine
Live translation in 99 languages — live on AddSub
Speaker diarization
AddSub separates speakers and labels each line with a persistent color-coded badge (S1, S2, S3…). Interviews, podcasts, and meetings become readable transcripts with who-said-what preserved.
- Persistent speaker identity across the session
- Color-coded badges that match the transcript
- Works with the real-time stream, not just offline files
- Calibrated on-device clustering (pyannote + wespeaker)
Speaker diarization — live on AddSub
Vision OCR
On-screen text — slides, code, UI labels — is read by the Apple Vision framework and interleaved with the audio transcript. Perfect for lectures, product demos, and tutorials.
- Reads slides and code as they appear
- Interleaves on-screen text with spoken captions
- Built on Apple Vision, on-device
Vision OCR — live on AddSub
Floating Liquid Glass overlay
A gorgeous native overlay floats above every app. It stays out of your way while watching, and expands on hover for the full transcript timeline.
- Floating window above all apps, all spaces
- Minimized capsule ↔ full timeline modes
- Copy any segment, copy all, or export to SRT
- Fully customizable: font size, opacity, text color
Floating Liquid Glass overlay — live on AddSub
100% on-device privacy
Every feature — transcription, translation, diarization, OCR — runs locally. Your audio never leaves your Mac. There are no servers, no accounts required, and no cloud costs.
- Nothing uploaded, ever
- No subscription or per-minute fees
- Works offline
- A single native binary — no background agents
100% on-device privacy — live on AddSub
Try every feature free for 7 days
No credit card. No accounts. Just download and watch.