Turn a raw AAC audio file into a widely compatible MP3.
The AAC to MP3 converter turns AAC audio (Advanced Audio Coding (often an ADTS .aac stream or inside M4A/MP4)) into MP3 (MPEG-1/2 Layer III) directly in your browser. Raw AAC streams and some downloads do not open in every player or editor; MP3 does.
AAC is the successor to MP3, used by YouTube, Apple Music and broadcast streaming; better quality than MP3 at equal bitrates. MP3 is the most universally supported lossy format; plays on virtually every phone, car stereo, browser and editor. Both AAC and MP3 are lossy, so this is a transcode: some extra quality is lost. Pick a bitrate at or above the original’s to limit the damage, and keep the original file.
Your file is decoded to 32-bit floating-point samples by the browser’s own audio decoder — and at the file’s own sample rate, not a resampled one. You can optionally resample or switch channels. It is then encoded to MP3 on your device; for a lossy target the result is decoded again for the preview, so you hear what you will get. Typical size: about 1 MB per minute at 128 kbps, 2.4 MB at 320 kbps.
Source format facts: AAC files are lossy; usual bandwidth: typically up to 20 kHz. Target facts: MP3 is lossy; usual bandwidth: typically low-passed at 16–20 kHz depending on bitrate.
Convert .aac captures for easy playback.
Make radio recordings portable.
Open the audio in software without AAC support.
MP3 plays on anything.
| From | AAC — Advanced Audio Coding (often an ADTS .aac stream or inside M4A/MP4) |
|---|---|
| To | MP3 — MPEG-1/2 Layer III |
| Direction | lossy → lossy |
| Typical size | about 1 MB per minute at 128 kbps, 2.4 MB at 320 kbps |
| Tags | AAC: limited → MP3: ID3 |
Yes, at the same bitrate; converting back to MP3 keeps most of that quality at a higher bitrate.
Yes, once loaded.
Going to WAV is lossless. Going to MP3 uses a standard 192kbps encode by default (adjustable), which is transparent for most listening but is a lossy step if your source was uncompressed.
No — the file is decoded and re-encoded entirely in your browser using the Web Audio API and, for MP3, a small bundled encoder. Nothing is sent anywhere.
This tool runs entirely in your browser using the Web Audio API. Nothing is uploaded, stored or shared — there is no server to send your file to, so it works offline once the page has loaded.
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