What audio formats can I upload for transcription?

mp3, mp4, m4a, wav, webm, ogg and flac, up to 100 MB per request. Duration is read with ffprobe for billing. For very long recordings, splitting into chunks of 20–30 minutes keeps latency predictable; transcription runs at roughly 0.04–0.05× real time (a 20-minute file in under a minute).