Free online audio converter
Convert AAC to MP3 in your browser
AAC to MP3 is a free converter that turns AAC audio — .aac, .m4a, .m4b, .m4r and audio-only .mp4 — into MP3 files at 128, 192, 256 or 320 kbps. It needs no signup and no software install, converts up to 20 files per batch at 100 MB each, and runs entirely inside your browser, so your audio is never uploaded to a server.
- 100% free
- No upload
- No signup
- Up to 320 kbps
- Batch of 20
- Works offline
Drop your AAC files here to convert them to MP3
.aac, .m4a, .m4b, .m4r and audio-only .mp4 — up to 20 files, 100 MB each
How to convert AAC to MP3
Three steps, no account, no upload. Files are decoded and re-encoded on your own device.
Add your AAC files
Drag .aac, .m4a, .m4b, .m4r or audio-only .mp4 files onto the drop zone, or press Choose AAC files to pick them from your device. You can queue up to 20 files at a time, 100 MB each.
Set the bitrate you want
Pick an MP3 bitrate between 128 and 320 kbps — 192 kbps is the default and matches typical AAC music quality. Sample rate can stay at 44.1 kHz or be switched to 48 kHz for video-sourced audio.
Convert and download
Conversion starts the moment a file lands in the queue and shows a live percentage. Press Download MP3 on any finished track, or Download all to save the whole batch at once.
Watch how it works
A 55-second walkthrough: drop an AAC file, pick a bitrate, download the MP3 — all inside the browser tab.
Technical specifications
| Input formats | AAC (.aac), M4A, M4B, M4R, audio-only MP4 |
|---|---|
| Output format | MP3 (MPEG-1 Layer III), constant bitrate |
| Bitrates | 128, 192 (default), 256, 320 kbps |
| Sample rate | 44.1 kHz (default) or 48 kHz |
| Channels | Mono and stereo preserved; 5.1 audio is down-mixed to stereo |
| Batch limit | 20 files per batch, 100 MB per file |
| Processing location | 100% on your device — Web Audio decodes the AAC, a LAME encoder in a Web Worker writes the MP3 |
| Price | Free — no signup, no watermark, no file limit per day |
| Works offline | Yes, once the page has loaded |
Frequently asked questions
How do I convert AAC to MP3?
Drop your AAC file onto the box at the top of this page, choose a bitrate (128, 192, 256 or 320 kbps), and press Download MP3 when the progress bar finishes. Nothing is installed and nothing is uploaded — the conversion runs inside this browser tab.
Is this AAC to MP3 converter free?
Yes, completely. There is no signup, no email, no file-count paywall and no audio watermark. All 4 bitrates and both sample rates are available to everyone.
Are my audio files uploaded to a server?
No. Your browser decodes the AAC natively and re-encodes it to MP3 with a LAME encoder running in a Web Worker on your own device. The audio never leaves your computer, which is also why the conversion works with the network disconnected.
Can I convert M4A to MP3 with this tool?
Yes. M4A is simply AAC audio inside an MP4 container, so it converts the same way. The tool also accepts .m4b audiobooks, .m4r iPhone ringtones and audio-only .mp4 files.
Does converting AAC to MP3 lose quality?
Slightly, because both formats are lossy — decoding AAC and re-encoding it as MP3 is a second generation of compression. Converting at 256 or 320 kbps keeps the loss inaudible for almost all listeners; 192 kbps is a good balance of size and fidelity for music.
Which bitrate should I choose?
Use 192 kbps for general music, 256–320 kbps if the source AAC was high quality and you want maximum fidelity, and 128 kbps for podcasts, audiobooks or voice memos where file size matters more than nuance. A 4-minute track at 192 kbps produces roughly a 5.8 MB MP3.
Can I convert several AAC files at once?
Yes. Drop up to 20 files in one batch and they convert one after another, each with its own progress bar and download button. Download all saves every finished MP3 in one click.
Why does my iTunes file refuse to convert?
Older iTunes purchases use the protected .m4p format, and DRM-protected audio cannot be decoded by any browser. Files bought or downloaded after Apple dropped DRM (.m4a) convert without a problem.
About this converter
AAC is the codec Apple, YouTube and most streaming services ship by default, and it is a better codec than MP3 at the same bitrate. The catch is reach: car stereos, DJ software, older MP3 players, gym equipment and plenty of embedded hardware still only read MP3. This tool exists to close that gap in one drag-and-drop, without asking you to hand a private recording to a stranger's upload form. If your files are specifically .m4a — iTunes tracks, Voice Memos, GarageBand exports — the dedicated M4A to MP3 converter page covers that case in detail. If you have a specific AAC audio file to convert to MP3, the dedicated page handles standalone .aac files, .m4b audiobooks and every other AAC container. For a broader look at AAC audio to MP3 conversion in general, see that variant. If you came from a device or app that labels its output as “AAC format” and you need MP3 instead, the AAC format to MP3 page explains the codec and walks through the conversion.
Two things happen when you drop a file. Your browser first decodes the AAC with the same audio engine it uses to play the file back, which is fast and needs no extra download. The raw audio then goes to a LAME encoder running in a Web Worker, which writes the MP3 frame by frame — on a background thread, so the page keeps responding while a long audiobook grinds through.
Both AAC and MP3 are lossy, so a conversion is always a second pass of compression. In practice that is inaudible at 256 kbps and above, and 192 kbps holds up well for music on ordinary headphones — the guide to converting without quality loss covers bitrate selection in detail. If you are archiving something irreplaceable, keep the AAC original alongside the MP3 you export here. Going the other way is a different question with a different answer — the guide on converting MP3 to AAC covers when that transcode is worth doing and which encoder to use.
Your audio never leaves this tab
There is no upload step and no conversion server — decoding and MP3 encoding both happen in your browser, so we never receive your recordings, their filenames or their metadata. Close the tab and the audio is gone from memory; nothing is written to disk and nothing survives to your next visit. Voice memos, interview tapes and unreleased mixes stay as private as they were before you opened this page.