Free Online Audio Compressor

An audio compressor can refer to a file compression tool or a dynamics processor. This online audio file compressor reduces file size by re-encoding audio. A dynamics compressor reduces the difference between loud and quiet passages. This tool does not balance volume, remove background noise or master a song.

This audio compressor re-encodes your recording as MP3 or M4A at your selected bitrate to reduce file size. The amount saved depends on the source format, original bitrate and output settings. There is no fixed reduction percentage, and an already compressed file can become larger. Compare the actual file sizes and preview the result before downloading.

No account, subscription or credits are needed. The browser downloads a self-hosted processing engine, then encodes your local file in a Worker. Your audio is not sent to MusicGo, R2 or an AI provider, and results are not saved to My works. Download the result before leaving.

Choose 64 or 96 kbps when a compact file matters most; 128 kbps is the default balance, while 192–320 kbps keeps more data. These are encoding choices, not promises of transparent quality. Listen for changes in cymbals, stereo detail and consonants before keeping a result.

Open MP3, WAV, M4A, AAC, FLAC, OGG, Opus, WebM audio or AIFF. Export a real MP3 or AAC-encoded M4A file. WAV and FLAC sources often offer more room for size reduction; converting lossy audio to another lossy format cannot restore missing detail.

A file already encoded at a low bitrate can grow when exported at a higher bitrate. Container overhead also adds bytes. Compare the actual sizes, lower the bitrate, or keep the original if there is no saving.

Choose one local audio file, select MP3 or M4A and a bitrate, then compress. Listen to the original and the processed result before downloading. The result panel compares actual byte sizes, so you can judge whether the settings helped.

There is no automatic target-MB setting. Choose a lower bitrate, compress, and compare the downloaded file with your destination’s limit. If it is still too large, try a lower setting or shorten the recording with Audio Cutter. An estimate does not guarantee an exact final size.

Choose 64 or 96 kbps when a compact file matters most; 128 kbps is the default balance, while 192–320 kbps keeps more data. These are encoding choices, not promises of transparent quality. Listen for changes in cymbals, stereo detail and consonants before keeping a result. For interviews, lessons and voice notes, a lower bitrate and mono may be practical. For music, consider a higher bitrate and preserve stereo if the spatial image matters. Keep the original recording as your editing master rather than repeatedly recompressing an MP3.

Choose MP3 when broad playback compatibility matters. Choose M4A if your destination accepts AAC audio. Neither format is always smaller or better: compare the actual size and listen before keeping the result.

Choose one file at a time, up to 50 MB on desktop or 20 MB on mobile. Keep the tab open and use Cancel to stop a job. Encoding speed depends on your device. Some browsers cannot preview every supported source format; try MP3 or M4A output and keep your original file.

One file is processed per job. Download the result, then choose another recording. This page does not provide batch processing or a ZIP download.

The compressor re-encodes the full recording without intentionally changing playback speed, pitch or trimming it. Codec padding can cause a small duration difference. Use Audio Cutter for deliberate trimming or speed changes.

The first run needs to download the processing engine. Encoding time depends on file length and device resources. Keep the tab open, close other heavy tabs, or try a smaller file. Check that the format and size are supported; cancel and retry if a job fails.