About .aac files
AAC is the codec inside M4A/MP4; bare .aac files from stream rippers and broadcast encoders transcribe directly too.
Where .aac files come from
Stream captures, broadcast logging, car-recorder audio.
What you get
Speaker labels
Multi-voice recordings come back with each speaker separated and labelled.
Word-level timestamps
Every word is timed — accurate SRT/VTT subtitles come straight out.
100+ languages
The language is auto-detected; mixed-language recordings are handled per sentence.
Every export
TXT, SRT, VTT, DOCX and JSON on every pack — no format paywall.
Questions people ask
Do I need to convert .aac to MP3 first?
No. Upload the .aac file exactly as it is — decoding happens server-side, and lossless or original-codec input transcribes better than a re-compressed MP3 anyway.
Is there a size or length limit for .aac files?
Files up to 10 hours each are accepted, and multi-gigabyte uploads resume if your connection blips.
How much does it cost?
The preview is instant with no signup. Credits are one-time purchases that never expire: $8 for 1,000 minutes, $12 for 2,000 minutes (about 36-48¢ per hour of audio).
Can I paste a link instead of uploading?
Yes — paste a direct link or a page URL and the audio is fetched server-side, which is faster than uploading from a slow connection.
Related: Audio to text · MP3 to text · Video to text · Subtitle generator