Audio Compressor Online for Free
Apply dynamic range compression to any audio file directly in your browser. Upload your track, set threshold, ratio, attack, release, and makeup gain, then download the compressed result. All processing runs locally on your device. No account, no server upload, no watermark.
Try It FreeWhat Is Dynamic Range Compression?
Dynamic range compression reduces the gap between the loudest and quietest parts of your audio. This is not file compression (making files smaller). It is audio processing that controls volume. A compressor watches the signal level. When the signal crosses a threshold you set, the compressor turns it down by a ratio you choose. The quiet parts stay the same. The loud parts get quieter. Then you apply makeup gain to bring the overall level back up. The result is audio that sounds more even and controlled. Vocals sit at a consistent level. Podcast speech stays audible without sudden jumps. Music feels tighter and more polished.
- Dynamic compression controls volume, not file size
- Reduces the gap between loud and quiet parts of audio
- Loud parts get turned down, quiet parts stay the same
- Makeup gain brings the overall level back up after compression
- Makes vocals, podcasts, and music sound more consistent
Compressor Parameters Explained
A compressor has five main controls. Threshold sets the level where compression starts. Any signal below the threshold passes through unchanged. Ratio determines how much the signal gets reduced once it crosses the threshold. A 4:1 ratio means that for every 4 dB above the threshold, only 1 dB comes through. Attack controls how fast the compressor reacts when the signal crosses the threshold. A fast attack catches transients immediately. A slow attack lets the initial punch through before clamping down. Release controls how quickly the compressor stops compressing after the signal drops below the threshold. Knee sets whether the compression engages gradually (soft knee) or all at once (hard knee).
- Threshold: the level (in dB) where compression begins
- Ratio: how much the signal above the threshold gets reduced (e.g., 4:1)
- Attack: how fast the compressor responds (milliseconds)
- Release: how fast the compressor lets go (milliseconds)
- Knee: gradual onset (soft) vs. immediate onset (hard)
- Makeup gain: volume boost applied after compression to restore overall level
When to Use Compression
Podcast producers use compression on every episode. Spoken word recordings have a wide dynamic range because people naturally vary their volume when talking. Compression keeps the whispers audible and the laughs from blowing out the listener's earbuds. Vocalists and voice actors compress their recordings so every word sits at a consistent level in the mix. Broadcast audio requires compression by regulation in many countries. Radio and TV standards specify maximum dynamic range to protect equipment and ensure audibility in noisy environments. Music producers compress individual tracks and the final mix to glue elements together and control energy.
- Podcasts: even out speech so listeners do not need to adjust volume
- Vocals: keep every word at a consistent level in the mix
- Broadcast: meet dynamic range standards for radio and TV
- Music production: control dynamics on individual tracks and the final mix
- Voice acting and narration: maintain consistent delivery across long recordings
Makeup Gain and Output Level
Compression turns loud parts down. That means the overall signal is quieter after compression. Makeup gain compensates by boosting the entire signal back up. The amount of makeup gain you need depends on how much compression you applied. Heavy compression (low threshold, high ratio) requires more makeup gain. Light compression (high threshold, low ratio) needs less. Some compressors calculate makeup gain automatically. Others let you dial it in manually. The goal is to match the perceived loudness of the uncompressed signal, or push it slightly louder if that suits the project. Watch your output meter to avoid clipping after adding makeup gain.
- Makeup gain compensates for the volume reduction caused by compression
- Heavy compression needs more makeup gain than light compression
- Automatic makeup gain works as a starting point, manual is more precise
- Watch the output level to avoid clipping after adding gain
- The goal: consistent loudness without exceeding 0 dBFS
Compression vs. Limiting
A limiter is a compressor with a very high ratio, typically 10:1 or higher (often infinity:1). Where a compressor gently reduces the signal above the threshold, a limiter stops it hard. Nothing gets through above the ceiling. Limiters are used as a safety net at the end of the signal chain. They catch stray peaks that would cause clipping. Compressors are used earlier in the chain to shape the dynamics of the performance. You might compress vocals at 3:1 to smooth them out, then put a limiter at -1 dBTP on the master bus to prevent any peak from clipping. Both tools control dynamics, but they serve different purposes at different stages.
- A limiter is a compressor with a very high ratio (10:1 or higher)
- Compressors shape dynamics gradually, limiters stop peaks hard
- Limiters go at the end of the signal chain as a safety net
- Compressors go earlier to control the performance
- Common setup: compress at 3:1 to 4:1, then limit at -1 dBTP on the output
Dynamic Compressor
Even out volume levels with professional dynamic range compression. Free, no signup, runs in your browser.
Frequently asked questions
How do I compress audio online for free?
Use the free dynamic compressor at /tools/dynamic-compressor. Upload your file, set threshold, ratio, attack, release, and makeup gain, then download. No signup, no server upload.
Is this file compression or audio compression?
Audio compression (dynamic range). This tool controls volume dynamics, not file size. If you want to reduce file size, you need an audio format converter (like WAV to MP3).
What settings should I use for podcasts?
A good starting point for podcast speech: threshold around -20 dB, ratio 3:1, attack 10 ms, release 100 ms. Adjust the threshold so the compressor catches the louder phrases without squashing everything.
What is the difference between compression and normalization?
Normalization applies the same volume change to the entire file. Compression changes the volume dynamically, reducing only the parts that exceed the threshold. Compression changes the dynamic range. Normalization does not.
Does this tool upload my audio to a server?
No. All processing runs locally in your browser. Your audio file never leaves your device.
Can I use compression and normalization together?
Yes. A common workflow is to compress first (to even out dynamics), then normalize to your target loudness. Compress your file with Orec's dynamic compressor, then run it through the LUFS normalizer.