Practical focus
Use this page when your source is AAC and you need smaller files or a more compatible MP3 copy.
Private browser-based audio compression
AAC Compressor
Compress AAC audio while choosing whether to keep efficient AAC output or convert to MP3 for compatibility.
Your audio is compressed locally in your browser. Files are not uploaded to a server.
MP3 / WAV / M4A / AAC / OGG / FLAC inputMP3M4A / AACOGG
File-
Size-
Duration-
Your audio is compressed locally in your browser. Files are not uploaded to a server.
Compression mode
Advanced settings
Select an audio file to begin.
Compression result
Original size-
Compressed size-
Saved-
Output-
Bitrate-
Quick tips
- AAC is usually efficient at a given bitrate.
- Converting AAC to MP3 is not automatically smaller.
- Voice can use lower bitrates than music.
How to use
- Keep AAC/M4A output when your priority is small size with good quality on modern devices.
- Choose MP3 output when the recipient, upload form, or older player may not handle AAC well.
- For voice, try 64-96 kbps; for music, start at 128 kbps or higher.
- If the source is already low-bitrate AAC, compare the result carefully because savings may be limited.
Recommended settings
| AAC content | Suggested setting |
|---|---|
| Voice | AAC or MP3, 64-96 kbps |
| Music | AAC, 128-192 kbps |
| Video-extracted audio | AAC, 96-128 kbps |
| Compatibility priority | MP3, 128 kbps |
| Small upload target | Target Size mode |
Supported formats
AAC audio may come from video exports, mobile devices, screen recordings, and media processing tools.
Use AAC/M4A output for efficiency or MP3 output when compatibility matters more than codec efficiency.
Quality vs file size
AAC is usually more efficient than MP3 at similar bitrates, so it may already be compact.
AAC to MP3 can make playback easier on more systems, but it may not reduce size if the chosen MP3 bitrate is higher than the source.
Music should rarely be pushed below 64 kbps. If the source AAC is already low bitrate, further compression can add artifacts quickly.
Privacy and local processing
Compression runs in your browser, so the original audio is not uploaded to a server.
Large files can still be slow because decoding and encoding use your device memory and CPU.
Things to watch
- Do not assume MP3 output will always be smaller than AAC.
- Check the original bitrate before compressing already-small AAC files.
FAQ
Is AAC smaller than MP3?
Often, AAC can sound similar to MP3 at a lower bitrate, but the actual size depends on the chosen bitrate and duration.
Should I convert AAC to MP3?
Convert to MP3 for compatibility. Keep AAC when efficient size and modern playback are the priority.
What bitrate is good for AAC audio?
Use 64-96 kbps for voice, 96-128 kbps for extracted video audio, and 128-192 kbps for music.
Can AAC be compressed further?
Yes, but if it is already low bitrate, the improvement may be small and quality may drop.
Why did my AAC file not shrink much?
The source may already be efficient, or the output bitrate may be close to the original.