Notch-based subtitle display
Celyn places translation inside the macOS notch so subtitles stay in the same place your eyes already are, instead of opening extra windows.
Celyn
Celyn is a macOS translation app with live subtitles in the notch and on-device speech processing for conversations, calls, and media.
Overview
Celyn is a macOS translation app that shows live subtitles in the notch and processes speech on-device. Its core job is to translate spoken language in real time without sending audio off your Mac, using Apple’s built-in speech and translation frameworks.
The app is designed for quick, low-friction use: press `⌥T` to start or stop translation, then choose microphone input, system audio, or both. It supports offline use after language models are available and is positioned for people who want live translation during calls, videos, podcasts, or in-person conversations.
Features
On-device processing
Speech recognition and translation run locally with Apple’s built-in frameworks, which keeps audio processing on your Mac and avoids sending data to a server.
Mic, system, or combined capture
The app can translate from microphone input, system audio, or both, which covers in-person conversations, calls, videos, and podcasts.
One-key control
A single hotkey, `⌥T`, starts or stops translation, so the main workflow is a simple toggle rather than a multi-step setup.
Offline operation
Celyn works without an internet connection after the necessary language models are available, making it usable in offline settings.
Broad language support
The app supports 19 languages and notes that it uses Apple’s built-in speech and translation frameworks, with language models downloaded as needed.
Use cases
In-person conversations
Use Celyn to translate spoken conversation in person by capturing microphone input and showing live subtitles in the notch.
Video calls and meetings
Use system audio capture during Zoom calls or similar meetings to follow speech without changing the rest of your workflow.
Video and audio playback
Use it while watching YouTube videos or listening to podcasts to translate spoken content as it plays on your Mac.
Mixed audio environments
Use the combined mode when you want system audio to take precedence but still have the microphone available as a fallback.
Offline travel or low-connectivity use
Use Celyn when you need translation without an internet connection after the required language models are already downloaded.
Pros and Cons
Pros
- Runs entirely on-device, with no audio recorded or transmitted.
- Works with microphone, system audio, or both, covering multiple translation scenarios.
- Uses a simple hotkey workflow that is quick to start and stop.
- Supports offline translation after the required models are downloaded.
- Covers 19 languages according to the site.
Cons
- Requires macOS 15.0 (Sequoia) or later, so older Macs are not supported.
- Relies on Apple’s built-in language models, so initial language downloads may be needed before offline use.
FAQ
What Mac do I need to run Celyn?
Celyn requires macOS 15.0 (Sequoia) or later. It works on both Apple Silicon and Intel Macs.
Does Celyn work offline?
Yes. Speech recognition and translation happen on-device, and no internet connection is required after the initial language model download.
Which languages are supported?
Celyn supports Arabic, Mandarin Chinese, Dutch, English, French, German, Hindi, Indonesian, Italian, Japanese, Korean, Polish, Portuguese (Brazilian), Russian, Spanish, Thai, Turkish, Ukrainian, and Vietnamese.
Does Celyn record or store my audio?
No. Celyn processes audio in real time and discards it immediately. Nothing is recorded, stored, or transmitted anywhere.
How do I activate a license key?
After purchase, you receive a license key by email. Open Celyn, click the language label in the notch to open Settings, and paste the key in the License section.
Quick Facts
- Category
- Translation
- Platform
- macOS
- Minimum OS
- macOS 15.0 (Sequoia)
- Pricing
- One-time purchase; $14 on the site
- Input sources
- Microphone, system audio, or both
- Website
- celyn.app
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