Free Toolkit

Audio CompressorApply dynamic range compression to reduce volume differences in audio.

Audio Compressor illustration
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Audio Compressor

Apply dynamic range compression to reduce volume differences in audio.

How to Use
1

Upload Audio

Drop your audio file or click to browse.

2

Set Parameters

Adjust threshold, ratio, attack, release, and knee settings.

3

Download

Download your compressed audio file.

What Is Audio Compressor?

The Audio Compressor applies dynamic range compression to reduce the difference between loud and quiet parts of audio. This makes quiet parts more audible and prevents loud peaks from distorting. Essential for voice recordings, podcasts, and music mastering. The tool uses the Web Audio API's DynamicsCompressorNode with adjustable threshold, ratio, attack, release, and knee parameters. Preview the compression in real-time with visual gain reduction metering, then download the processed audio.

Why Use Our Audio Compressor?

  • Adjustable threshold, ratio, attack, release, and knee parameters
  • Visual gain reduction meter shows compression in action
  • Real-time preview before downloading
  • Browser-based processing — files stay private

Common Use Cases

Podcast Production

Even out volume differences between speakers or recording conditions.

Voice Recording

Make whispers and loud speech more consistent in volume.

Music Mastering

Control dynamic range for consistent playback across devices.

Broadcast

Prepare audio for broadcast standards that require controlled dynamics.

Technical Guide

The compressor uses the Web Audio API's DynamicsCompressorNode, which implements a feed-forward compressor with look-ahead. Parameters include: threshold (-100 to 0 dB) — the level above which compression starts; ratio (1:1 to 20:1) — how much the signal is reduced above threshold; knee (0-40 dB) — how gradually compression engages; attack (0-1 seconds) — how quickly compression responds to transients; release (0-1 seconds) — how quickly compression stops after signal drops below threshold. The audio is processed through an OfflineAudioContext with the DynamicsCompressorNode in the signal chain. The node's reduction property provides real-time gain reduction readings for metering. Post-compression, a makeup gain GainNode can be applied to restore overall volume.

Tips & Best Practices

  • 1
    Start with gentle settings: -20 dB threshold, 4:1 ratio, 10ms attack, 100ms release
  • 2
    Use slower attack times (20-50ms) to preserve transients in music
  • 3
    For voice, faster attack (5-10ms) and slower release (200-300ms) works well
  • 4
    Apply normalization after compression to maximize the overall volume

Related Tools

Frequently Asked Questions

QWhat is dynamic range compression?
Compression reduces the volume difference between the loudest and quietest parts of audio, making the overall level more consistent.
QIs compression the same as making things louder?
Not exactly. Compression reduces peaks, which allows you to then increase overall volume (makeup gain) without clipping.
QWhat's a good ratio for voice?
A 3:1 to 6:1 ratio works well for voice recordings. Start at 4:1 and adjust to taste.
QWill it make my audio sound squashed?
Over-compression can sound unnatural. Use moderate settings and preview before downloading.
QIs processing done locally?
Yes. All compression processing happens in your browser. No files are uploaded.

About Audio Compressor

Audio Compressor is a free online tool from FreeToolkit.ai. All processing happens directly in your browser — your data never leaves your device. No registration required. No ads. Just fast, reliable tools.