Audio Compressor Online - Free
A compressor evens out the volume of your audio. When something gets louder than the threshold you set, the compressor turns it down. The result: loud parts are controlled and quiet parts become more audible. Important: this is dynamic range compression (volume control), not file compression like MP3 or ZIP. If you need to reduce file size, use the Convert tool instead.
A compressor evens out the volume of your audio. When something gets louder than the threshold you set, the compressor turns it down. The result: loud parts are controlled and quiet parts become more audible. Important: this is dynamic range compression (volume control), not file compression like MP3 or ZIP. If you need to reduce file size, use the Convert tool instead.
Problems This Tool Solves
One speaker is much louder than the other in my podcast
Set threshold around -20 dB and ratio at 3:1–4:1. The compressor tames the loud speaker so both sit at a similar level.
My audio sounds quieter after compression, not louder
Expected. Compression turns down loud parts. Apply Normalize afterward to bring the overall level back up.
I do not understand what threshold, ratio, attack, and release mean
Threshold: how loud a signal must be before compression kicks in. Ratio: how much it is turned down. Attack: how fast it reacts. Release: how fast it lets go. Start with a preset and adjust from there.
Audio sounds like it is breathing or pumping between words
The release time is too fast - the compressor lets go between syllables and you hear the volume surging up and down. Increase release to 150–250 ms for smoother behavior on speech.
Common Use Cases
Even out a podcast with two speakers
One speaker is louder than the other. Compression brings the loud speaker down so both sit at a similar level.
Control vocal peaks in narration
A narrator who gets excited hits peaks that are 10–15 dB louder than their normal level. Compression tames those peaks.
Make a voice memo easier to hear
Background noise and uneven recording distance make parts hard to hear. Compression brings the quiet parts closer to the loud ones.
Prepare audio for streaming or broadcast
Streaming platforms and broadcast standards expect a controlled dynamic range. Compression followed by normalization gets you there.
How to Compress Audio Dynamics Online
- Upload your audio file to the editor.
- Open the Compressor in the Effects section. Set threshold, ratio, attack, and release.
- Preview the result in real time. Watch for 3–6 dB of gain reduction on loud parts.
- Click Apply, then use Normalize to bring the overall level back up. Export when satisfied.
Compressor vs Normalize vs Increase Volume
Compressor
Reduces the gap between loud and quiet parts. Changes the dynamic range of your audio.
Best for: uneven recordings, podcast leveling, taming peaks, broadcast complianceNormalize
Scales the whole file to a target peak. Does not change the balance between loud and quiet.
Best for: maximizing overall level, matching volume across filesIncrease Volume
Adds a fixed gain. Loud and quiet parts both get the same boost.
Best for: quick manual boost when you know the exact dB amountStarting Presets by Content Type
| Content | Threshold | Ratio | Attack | Release |
|---|---|---|---|---|
| Podcast / speech | -20 dB | 3:1 | 10 ms | 150 ms |
| Voiceover / narration | -18 dB | 4:1 | 5 ms | 100 ms |
| Music (gentle glue) | -12 dB | 2:1 | 20 ms | 200 ms |
| Aggressive leveling | -24 dB | 6:1 | 1 ms | 50 ms |
Podcast Processing Chain
- Remove Noise - Clean noise before compression amplifies it
- Equalize - Shape tone so the compressor reacts to your intended sound
- Compress - Even out dynamics between speakers and sections
- Normalize - Bring the compressed result to a professional loudness level
Quick Tips
- Aim for 3–6 dB of gain reduction on peaks. If the meter shows more than 10 dB of reduction, the threshold is too low or the ratio too high.
- Always add makeup gain (or Normalize) after compressing. Compression makes the audio quieter - you need to bring the level back up.
- Use a slower attack (10–20 ms) for natural speech. A very fast attack can make words sound flat and lifeless.
- If the audio sounds like it is "breathing" or "pumping," try a longer release time (150–250 ms).
- Good compression should be barely noticeable. If you can clearly hear it working, back off.
- Toggle before/after frequently. Compression is subtle - your ears adjust quickly, so regular A/B comparison is the only way to stay objective.
Common Misconceptions
Myth: Compression and MP3/ZIP compression are the same thing
Reality: Completely different. Audio compression controls volume dynamics. File compression (MP3, ZIP) reduces file size. This tool does volume control, not file size reduction.
Myth: More compression always makes audio sound better
Reality: Over-compression strips dynamics and makes audio flat and lifeless. Aim for 3–6 dB of gain reduction. If everything sounds squashed, you have gone too far.
Common Problems and Fixes
Audio sounds quieter after compression
That is expected. Compression turns down the loud parts. Apply Normalize after compressing to bring the overall level back up.
Audio sounds flat and lifeless
Too much compression. Raise the threshold (less compression) or lower the ratio. A 2:1 ratio is gentle, 8:1 is aggressive.
Pumping or breathing sound
The release time is too fast. Increase it to 150–250 ms so the compressor releases more smoothly.
Compression is not doing anything noticeable
The threshold is set above the loudest peaks. Lower the threshold until you see 3–6 dB of gain reduction on the loud parts.
Background noise got louder after compression
Compression brings quiet parts up relative to loud parts, which includes the noise floor. Run Noise Removal before compressing to avoid amplifying hiss and hum.
Why Use This Audio Compressor Online
- Full control: threshold, ratio, attack, and release
- Real-time preview with gain reduction metering
- Works on speech, voice, music, and any audio content
- Combine with Normalize for broadcast-ready results
- All processing runs locally in your browser
Frequently Asked Questions
Is this the same as file compression (ZIP or MP3)?
No. This is dynamics compression - it controls volume, not file size. MP3 and ZIP reduce file size. A dynamics compressor changes how loud and quiet parts relate to each other.
What ratio should I use?
2:1 is gentle - barely noticeable. 4:1 is moderate - good for podcasts. 8:1 is heavy - noticeable control. 20:1 acts like a limiter - hard ceiling on peaks. Start at 3:1 or 4:1 for speech.
Should I compress before or after EQ?
For most work, EQ first, then compress. This way the compressor reacts to your already-shaped tone. Some engineers reverse this order for specific effects, but EQ-first is the standard starting point.
Why does my audio sound worse after compression?
Usually too much compression. Raise the threshold, lower the ratio, or both. If the gain reduction meter shows more than 6–10 dB, you are likely overdoing it. Good compression is subtle.
Why can’t I hear what the compressor is doing?
Compression is subtle by design. Toggle the before/after comparison to hear the difference. Focus on whether quiet parts are now more audible relative to loud parts, not on an obvious change in character. If the gain reduction meter shows 3–6 dB on peaks, it is working.
What is makeup gain and why do I need it?
Compression turns loud parts down, so the overall file sounds quieter. Makeup gain (or Normalize after compressing) brings the level back up. Without it, compressed audio often sounds worse simply because it is quieter, not because the compression is wrong.
Should I use a compressor or limiter for my podcast?
A compressor at 3:1–4:1 for general leveling. A limiter is an extreme compressor (20:1 or higher) - use it as a safety net to catch stray peaks that the compressor misses, not as the main tool.
I cannot hear what the compressor is doing - is it working?
Compression is deliberately subtle. Toggle before/after comparison and focus on whether quiet parts are now closer in volume to loud parts. Watch the gain reduction meter: if it shows 3–6 dB of reduction on peaks, the compressor is working. The change should be felt more than heard.
What is parallel compression?
Parallel compression (also called New York compression) blends a heavily compressed version of the audio with the uncompressed original. The result keeps the natural dynamics of the dry signal while adding the body and sustain of the compressed one. To do this, duplicate the file, compress one copy aggressively, then merge the two at different volumes.