Where it goes wrong
- There is no index, so a player guesses the length and often can’t jump ahead.
- Car stereos, Windows apps and upload forms often list M4A but not bare .aac.
- MP3 has opened in every player for decades.
Convert AAC to MP3
A bare .aac file sounds fine but trips up many players: a wrong length, no seeking, sometimes no sound at all. As an MP3 it plays on anything. The recording stays with you: we never receive it or keep it.
or drop a file anywhere on this page
AAC files only · other formats open in “Audio converter”
Your privacy comes first
Your contracts, passport scans and family videos stay yours. No one but you gets to see them.
We never store your files
They don’t even reach us: your phone or computer does the work. Nothing to delete later.
100% free
No daily limits, no file-size cap, no paid Pro plan.
No sign-up
No account to create, no email to give. No account, nothing to hack.
How it works
- Open the .aac fileFrom a call recorder, a radio recording or a tool that copied the sound out of a video.
- Keep Good192 kbps keeps a 128 kbps AAC sounding the same. For speech, Standard is enough.
- Save the MP3Same name, now .mp3. The .aac file is not touched.
What a .aac file is and why players struggle
AAC is the codec inside nearly every M4A and MP4. A file that ends in .aac is that sound with no box around it, a plain stream of frames called ADTS. Android call and voice recorders, internet radio rippers and tools that copy the sound out of a video (ffmpeg with -c copy, for one) write it that way.
Pick a bitrate above the AAC’s
- AAC is more efficient than MP3, so the MP3 needs more bits to sound the same.
- A 128 kbps AAC: keep Good, 192. A 256 kbps AAC: choose Best, 320.
- A voice recording at 64 kbps or less: Standard, 128, and Mono under the gear.
- Measured: a one-minute 128 kbps AAC of 0.98 MB became a 1.44 MB MP3 at 192 kbps.
This page or M4A to MP3?
This page takes bare .aac files. An .m4a holds the same AAC sound in an MP4 box, like an iPhone voice memo, and has its own page, M4A to MP3. Both end up as the same kind of MP3.
Limits
- The sound has to be decoded: Chrome and Edge can, Firefox from version 130, Safari from 26.
- A file named .aac that is really an M4A inside goes to the audio converter, which takes both.
- Lossy to lossy can’t add detail. If a WAV or a FLAC of the same recording exists, convert that one.
Free, fast and all yours
Free forever
Every tool is free and will stay free. No trial, no ads, no paid plan.
No sign-up, no login
Open the page and start. No account, no email, no password.
Instant
Nothing to upload and no queue: a video opens in a second, a simple trim saves in seconds.
No file size limits
We set none. A file can be as big as your device can handle.
No watermarks, no copyright
No logo on top and no rights claimed: what you make is 100% yours.
Made for phones too
The same tools on iPhone, Android and a computer, with big buttons and plain words.
Questions
A little, because both formats are lossy. With a bitrate one step above the AAC’s, it is very hard to hear.
At the same bitrate AAC sounds slightly better. People convert for compatibility, not for sound.
A bare AAC stream has no index, so players estimate the length from the start of the file. An MP3 shows it correctly.
AAC is the sound; M4A is a file that holds AAC with an index and tags. A .aac file is AAC without that box.
Choose Best, 320 kbps. That is the top of what MP3 offers, and it keeps a 256 kbps AAC sounding the same.
Yes. Open the .aac from the recorder’s folder in Chrome on the phone, keep Standard for speech and save.
No. The AAC to MP3 conversion runs on your device and the file never reaches us, so there is no copy to keep.