Auto captions without uploading your video.
Most auto-captioning tools upload your video to their servers. Caption Build does everything on your computer: transcription, editing and export. You can caption on a train with no connection, and your footage never leaves your machine.
How transcription works without internet
Caption Build uses Whisper, OpenAI's speech recognition model, in a version that runs directly on your computer. The model is downloaded once, then everything happens locally.
Each word's timing is computed at the same time, on your machine, with no third-party service.
Why caption locally
- Privacy: your videos, including unpublished or client footage, aren't uploaded to a server.
- No upload wait: no need to send a multi-gigabyte file before you start.
- No quota: the work happens on your machine, so there are no transcription minutes to buy.
- Works anywhere: on the go, on a slow connection, or with no connection at all.
Real software, not a web app
Caption Build is an app installed on Mac and Windows. One license covers two machines and is bought once. Video export is local too, with no watermark, in 9:16, 1:1, 4:5 or 16:9, or as an SRT file.
Frequently asked questions
Do I need an internet connection to use Caption Build?
To download the app and the transcription model, and to activate your license, yes. After that, transcription, editing and export work offline.
Is local transcription as accurate as online?
Caption Build uses Whisper, the same kind of model many online tools use. You can pick a fast mode or a more accurate one depending on your computer's power.
Which computers are supported?
Mac and Windows. One license works on two machines.
Your videos stay with you. So do your captions.
Join the waitlist to try Caption Build for free during the beta.
Join the waitlistMac + Windows · No subscription · Free sign-up