What is Audio Compressor?

Reduces audio file size by re-encoding at a lower bitrate. Supports MP3, WAV, OGG, and other common formats. All processing happens on your device — your files never leave it.

FFmpeg runs locally through WebAssembly, so the file you pick is processed on your device and never uploaded. Output is MP3 or AAC at one of six bitrates (64, 96, 128, 192, 256, 320 kbps), in either constant (CBR) or variable (VBR) mode. The 100 MB per-file ceiling exists because FFmpeg has to hold the whole file in memory during the re-encode.

How to use

1. Upload an audio file (MP3, WAV, OGG, FLAC, or AAC) by dragging it onto the drop zone or clicking to browse.
2. Choose your target format and quality level. Lower bitrates mean smaller files but reduced audio quality — preview before committing.
3. Click Compress to process the file, then download the compressed result. Compare file sizes to see how much space you saved.

When to use

• Trimming a podcast WAV down to a 128 kbps MP3 small enough for email or Discord.
• Shrinking voice memos before importing them into a video editor that chokes on large files.
• Preparing background loops for a website where every kilobyte counts toward load time.

Result

A podcaster has a 45MB WAV recording and needs to email it. They compress it to 128kbps MP3, reducing it to 4MB while maintaining clear speech quality.

FAQ

What bitrate should I pick for speech versus music?

Speech sits comfortably at 64 to 96 kbps mono with no audible loss. Music starts to thin out below 128 kbps and most listeners can't tell 192 from 320 kbps unless they're on studio monitors. 256 is a reasonable middle ground.

Why does the compressed file sometimes end up larger than the original?

If the source is already a low-bitrate MP3, re-encoding at 256 or 320 kbps writes more data than was originally there without recovering quality. Pick a bitrate at or below the source's bitrate to actually shrink the file.

Why is there a 100 MB limit?

FFmpeg runs inside your tab as WebAssembly, so the whole file plus its working buffers have to fit in the memory available on your device. 100 MB keeps the encoder responsive on a laptop and avoids running a phone out of RAM.

Does compressing twice lose more quality?

Yes. Each lossy re-encode (MP3 to MP3 or MP3 to AAC) discards more high-frequency detail. If you have the original WAV or FLAC, compress straight from there instead of re-compressing an already lossy file.

Will compression affect the audio length?

No, the duration stays identical to the source. Only the bitrate (and therefore the file size and frequency resolution) changes. The waveform you'd see in an editor would look almost the same at lower zoom levels.

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