Read this before you install
This is a beta. It is early software and it can break. Expect rough edges, the occasional crash, and features that change between versions. Keep your original video files, and don't treat an export as your only copy.
It isn't signed with an Apple Developer certificate yet. That certificate costs $99/year and hasn't been bought yet, so macOS will refuse to open the app the first time and warn you that it can't verify the developer. That warning is expected. Step 4 below shows how to get past it, and it only happens once.
Apple Silicon only. There is no Intel build. On an Intel Mac, use the browser version instead, which works everywhere.
Why use the Mac app instead of the browser?
The web tool is deliberately limited by what a browser tab can do. Every visitor has to download the speech model before anything happens, so it can only justify the small ones. The Mac app downloads a model once and keeps it, which changes what's possible:
- Much better transcription. Choose anything from
tinyup tolarge-v3-turbo(1.6 GB). The big models are dramatically more accurate on accents, fast speech and background noise. - GPU acceleration. Transcription runs through Apple Metal on your Mac's GPU, so even the largest model is quicker than the small one was in a browser tab.
- Batch mode. Drop in a folder's worth of clips, set one style, and caption them all in a single run.
- Much faster export. Captions are burned in by ffmpeg with libass rather than rendered frame by frame, which is roughly 50× quicker on typical clips.
- Saveable projects. Corrected transcripts and styling save to a project file, so reopening a clip doesn't mean transcribing it again.
- Genuinely offline. After the model download, you can turn off your Wi-Fi and it works exactly the same.
What you need
- MacApple Silicon, M1 or later
- macOS12 Monterey or newer
- Disk~200 MB app + 75 MB–1.6 GB model
- PriceFree, no account
Not sure which Mac you have? Click the Apple menu → About This Mac. If the Chip line says Apple M1, M2, M3 or M4, you're set. If it says Intel, this build won't run, so use the browser version.
How to install
- Download the DMG. Download Karaoke Captions, a single
.dmgfile, about 28 MB. - Open the disk image. Double-click the downloaded
.dmg, then drag Karaoke Captions onto the Applications folder shortcut. - Try to open it. Open Applications and double-click Karaoke Captions. macOS will block it and say it can't verify the developer. This is the expected warning, so click Done.
- Allow it in System Settings. Open System Settings → Privacy & Security, scroll down to the Security section, and you'll see a line saying "Karaoke Captions" was blocked. Click Open Anyway, then confirm with Open. You only ever do this once.
- Pick a speech model. On first launch the app asks which model to download. Base (148 MB) is a good place to start; large-v3-turbo (1.6 GB) is the most accurate. You can change or add models later in Settings.
- Drop in a video. Drag a clip onto the window and it transcribes, previews and exports from there.
On older macOS versions you may instead be able to right-click the app and choose Open. On macOS Sequoia and later that shortcut no longer works, so use the System Settings route above.
Why does macOS warn me about this app?
Apple lets developers pay $99/year for a Developer ID certificate and submit each build to be notarized. Apps that go through it open with no warning. Apps that don't get stopped by Gatekeeper, whatever they actually do.
This beta hasn't gone through that yet, so you get the warning. It's worth being straight about what that means rather than talking you out of it: the warning is real, and treating these prompts as noise is a genuinely bad habit. macOS is telling you it cannot confirm who built this app or that it hasn't been tampered with, and for an unsigned download it can't. That is a judgement call only you can make, based on whether you trust where you got it from.
The certificate is planned. Once it's in place the warning disappears, and the app updates itself into the signed version with nothing for you to re-download.
If you'd rather not make that call, the browser version does the core job with no install and no security prompt at all.
Updates
The app updates itself. It checks shortly after launch and shows a small prompt when a new version is out; you can also check any time from Karaoke Captions → Check for Updates… in the menu bar. Choosing to update downloads the new version, verifies its signature cryptographically, installs it in place and offers to restart. There's no DMG to re-download, and because it's a beta there will be updates.
Privacy
Nothing about your video is uploaded. Not the file, not the audio, not the transcript. Transcription runs on your own GPU using a model stored on your disk. The app reaches the network for exactly two things: downloading a speech model when you ask for one, and checking whether an update exists.
Mac app FAQ
Is the Mac app free?
Yes. Free, no watermark, no account, no export limit. It's an open beta.
Why does macOS say the app can't be verified?
It isn't signed with a paid Apple Developer certificate yet, so Gatekeeper blocks the first launch. Go to System Settings → Privacy & Security → Open Anyway. Once only.
Does it work on Intel Macs?
No. Apple Silicon only (M1 or later), because transcription uses Apple Metal. On Intel, use the browser version.
Is my video uploaded anywhere?
No. Everything runs locally, and the app works with the network off once a model is downloaded.
How is it different from the browser version?
Bigger and far more accurate speech models, GPU acceleration, batch captioning, roughly 50× faster export, and saveable projects.
How do updates work?
Built in. The app tells you when a new version exists, then downloads, verifies and installs it in place and offers to restart.
What if it breaks?
It might. That's what beta means. Keep your original video files, and if an export looks wrong, re-run it with a larger speech model before assuming the clip is at fault.
Get the Mac beta
Free, on-device, no watermark. Apple Silicon, macOS 12+.
Download for Mac → Beta · not yet Apple-signed · see the install steps above