developed by Dolby, AT&T, Fraunhofer and Sony as the successor of MP3; a standard of MPEG-4 since 1999
AAC to text
Transcribe an AAC file to text
Transcribe an AAC file to text: upload the file, get a line per segment with timecodes and speaker labels. Export TXT, SRT, VTT or CSV. Free $0, 3 files a day.
3 files a day up to 30 minutes, free99+ languagesSpeaker separation and timestamps
In short
Upload the AAC and get the text: one line per segment, a timecode on every line, speakers named on request. AAC is a codec, not a wrapper, so.aac and.m4a are read the same way. One file is up to 30 minutes; the free plan is $0.
How to transcribe an AAC file
- 1
Upload the .aac or the .m4a
Both extensions are on the list of accepted files. The wrapper is opened for you, and the AAC audio inside it is what the engine reads.
- 2
Choose the language and the voices
Rthe recording language is detected automatically. With two speakers in the recording, switch the split on and every line is attributed to the right one.
- 3
Take the transcript out
Every line keeps the time it starts and ends. Export TXT, Markdown, SRT, VTT or CSV on any plan, and DOCX on the Pro plan.
What you get
- TXT
Plain text for an email, a note or a chat
- SRT
Subtitles for video editors and platforms
- VTT
Subtitles for a browser and a website
- CSV
A table: time, speaker, text
- DOCX
A Word document with speakers and times
- Markdown
Text with headings for notes
What AAC is, and what comes back from the file
96 kbit/s is enough for modest stereo demands, 128 kbit/s for transparency, 384 kbit/s for 5.1
the same audio is usually shipped in an MP4 box with the extension .m4a; a bare .aac file is the codec alone
audio and video are both accepted: mp3, wav, m4a, mp4, webm, ogg, flac, aac, wma, mov
The case
Why the extension tells only half the story
AAC is a compression standard, not a container: Dolby, AT&T, Fraunhofer and Sony built it as the successor of MP3, and it holds more of the sound in the same number of bits. The same audio usually travels inside an MP4 box with the extension.m4a, while a bare.aac file is the codec on its own. The transcript is made from the audio in both cases, and the limits do not change: up to 30 minutes for one file.
Tips
A .m4a from a phone and a .aac from a recorder take the same path.
Ask for the speaker split before a call with two people.
Read the opening minute before the export.
Export SRT if the recording goes under a video.
Questions this page answers
Why does AAC sound better than MP3?
AAC was designed as the MP3 successor and generally reaches a higher sound quality at the same bit rate. Wikipedia puts transparent stereo at 128 kbit/s, with 96 kbit/s already enough for modest demands.
What is the difference between .aac and .m4a?
The codec is the same in both. An .m4a file is AAC inside an MP4 container, an .aac file is the bare stream. The service reads the audio out of either one, and the limits are the same.
Does the transcript translate what was said?
No. A transcription is the words that were spoken, in the language they were spoken in. 99+ languages are supported, and a mix of the two is written as it was said.
Is there a licence to pay for the codec?
No licence and no payment are needed to play or stream an AAC file. The patents of the codec belong to the makers of the encoders, not to the people who play the file.
Sources
- EWikipedia — Advanced Audio Codingen.wikipedia.org · checked 22 October 2026
- TTranscribsi — the pricing pagetranscrib.si · checked 22 October 2026
Reading: 5 minutesUpdated Transcribsi editorial team
Drop a recording — the text arrives in a minute
Speakers by name, a time on every line, export to TXT, SRT, VTT, CSV and Markdown.
3 files a day up to 30 minutes, free99+ languagesSpeaker separation and timestamps