Caption Comet transcribes video and burns in styled captions entirely on-device, using bundled Whisper large v3 models rather than a cloud API — nothing gets uploaded, and no account is required. Assign a workflow to its Dock icon and drag a folder of mixed horizontal and vertical clips onto it to process the whole batch at once. The free version watermarks exports and caps them at 30 seconds; a one-time Pro purchase removes both.