AAC to MP3 a loose .aac as an MP3 every player understands.
To convert AAC to MP3, pick the .aac file, leave the format on MP3 and download it. The MP3 comes out at a constant 192 kbps, with the right length and a seek bar that lands exactly where you click, which a loose .aac doesn't always have. It handles plain AAC and radio HE-AAC. Free, no sign-up.
Free, no sign-upLarge video: extracting can take a few minutes. Keep this tab open until it finishes.
How to turn AAC into MP3
- 01
Pick the .aac
Drag the file into the dashed box or tap to choose it. A call recording, a radio capture or a recorder file all work.
- 02
Check channels and rate
Voice recordings sound best in mono. For video, use 48 kHz; for music, 44.1 kHz, the CD rate.
- 03
Download the MP3
The button shows the percentage and the time left. When it is done, download the .mp3, named after the file.
What an .aac file is and where it comes from
AAC is the compression format that followed MP3: at the same bitrate, it sounds better. Most of the time it lives inside a container, like the iPhone's M4A or the MP4 of a video. An .aac file is that same audio without the container, in a stream called ADTS, where every small slice of sound carries its own header.
This loose format shows up in Android call and screen recorders, internet radio captures, some voice recorders and files pulled from cameras and security systems. It is handy for recording nonstop, since the file never has to be closed at the end, but it charges a price when you play it back.
| Extension | What's inside | Page |
|---|---|---|
| .aac | Loose AAC (ADTS) | This one |
| .m4a | AAC in an MP4 container | M4A to MP3 |
| .mp4 | Video with AAC audio | MP4 to MP3 |
Why an .aac shows the wrong length or won't seek
Since an .aac has no index, the player has to guess the length from the file size and doesn't know which byte minute 42 starts at. That is why you see a 00:00 length, a seek bar that won't move or a jump that lands in the wrong place. Some car stereos, older players and video editors refuse the extension outright.
The MP3 we write has a constant bitrate and a header with the total frame count. The length shows correctly and jumping to 42:10 lands on 42:10. That matters when the audio goes into an editor, a transcript or to someone who has to review one passage.
- Length shows 00:00 or the wrong time: convert to MP3.
- Seek bar won't move: the MP3 fixes it.
- Copy-protected (DRM) music won't open in any converter.
Does AAC to MP3 lose quality?
A little, because you are re-encoding one lossy format into another. To avoid stacking losses, the MP3 comes out at 192 kbps, above what the original AAC usually has. A 128 kbps AAC becomes an MP3 nobody can tell apart in normal listening. It can't improve the sound: a 48 kbps radio AAC still sounds like radio.
HE-AAC, used by internet radio and very low bitrate recordings, stores the highs in a special way that some older players ignore, so the sound turns dull. When converting, we read those highs and the MP3 comes out with the full sound.
| Source | Typical bitrate | 1 minute as AAC | 1 minute as MP3 |
|---|---|---|---|
| Downloaded music | 256 kbps | 1.9 MB | 1.4 MB |
| Voice recorder | 128 kbps | 0.96 MB | 1.4 MB |
| Internet radio (HE-AAC) | 48 kbps | 0.36 MB | 1.4 MB |
More than AAC to MP3. The recording as text, with the time of every line.
See also
Frequently asked questions
How do I convert AAC to MP3 for free?
Pick the .aac file on this page, leave the format on MP3 and click convert. The MP3 comes out at 192 kbps, named after the original. It is free, with no sign-up, no watermark and no usage limit.
Are AAC and M4A the same thing?
The sound is the same; the container differs. An M4A holds AAC in an MP4 container, with an index, cover art and tags. An .aac is the loose audio. This page converts both, and M4A has its own page.
Why does my .aac show a 00:00 length?
An .aac has no index, so the player tries to guess the length and sometimes gives up. Once converted to MP3, the length shows correctly and the seek bar works.
Will the MP3 sound worse than the AAC?
The difference is very small, because the MP3 comes out at 192 kbps, above the bitrate of most .aac files. The sound doesn't improve, and it doesn't get noticeably worse on voice either.
The file didn't open. What could it be?
If it is music bought with copy protection, no converter opens it. If it is a recording, check that the file is larger than 0 KB and try an up-to-date Chrome or Edge on a computer.
Can I transcribe an .aac recording?
Yes, with no conversion first. Upload the .aac to FilmScribe and we transcribe it word by word, with the time of each line and who said it. You download TXT, PDF or SRT.
An hour of conversation in that recording? We transcribe it and you find every line.
Upload the .aac as it was recorded. We transcribe it word by word, with the time of each line, and you download the text or just the passage that matters.
See the result on your own recording before adding a card.