Transcription Languages
The 10 supported languages and how to manage their packs.
Transcription uses Apple's on-device speech-to-text models. Each language needs its model downloaded once, after which it works offline.
Supported Languages
Cantonese, Chinese, English, French, German, Italian, Japanese, Korean, Portuguese, Spanish.
Language Packs
Settings ▸ Transcription Languages lists every language and whether its model is installed, and is where you install and uninstall them.
macOS caps how many speech models can be installed at once. On reaching it you get Maximum Languages Reached, and you have to uninstall one before adding another. The limit is set by macOS, not by Silkwave Video.