—RMS dBFS
—PEAK dBFS
—CREST dB
COMP / AVAILABLE NOW
Audio Compressor
Tame peaks and level dynamics. Shape dynamic range with threshold, ratio, attack, release, soft knee, and makeup gain, then export WAV or a smaller MP3.
COMP / dynamics workbenchLinked dynamics processing in a local worker
THRESHOLD -18 dB
GAIN REDUCTION0.0dB MAX3:1 ratio
—RMS dBFS
—PEAK dBFS
—CREST dB
SOURCE —MP3 EST. —FILE SIZE AFTER RENDER
Original and compressed previews appear here after you choose a file.
GUIDE / audio compressor online
What is audio compression?
Audio compression can mean two related but different jobs. A dynamics compressor reduces the gap between strong peaks and quieter passages by applying changing gain above a threshold. File compression reduces storage size through an audio codec and bitrate. SoundTools performs real linked-channel dynamics processing first, then lets you keep an uncompressed WAV or encode a smaller MP3 locally.
RELATED USES
- compress audio online
- dynamic range compressor
- MP3 compressor
- reduce audio file size
- voice compressor
FIELD NOTES / 01
A real local processor, not a decorative upload box
Linked envelope follower + soft-knee compressor worker runs after you choose a source and explicitly start the operation. The audio samples remain in browser memory; SoundTools does not send the selected media to an application endpoint.
Start with Podcast, Voice Level, Music Glue, or Peak Control, then adjust threshold, ratio, attack, release, knee, and makeup gain. The meter reports RMS, peak, crest factor, maximum gain reduction, and any final peak protection before export. Results remain available for preview and download only in the current tab. Closing or refreshing the page releases those temporary objects.
REFERENCE / MODE CHOICE
Dynamics compression vs file compression vs normalization
These operations solve different problems. This page performs dynamics compression and offers MP3 file compression at export; use normalization when one constant gain change is the real goal.
| Method | Best for | What it measures | Important limit |
|---|---|---|---|
| Dynamics compression | Taming peaks and leveling speech or music | A changing envelope above a threshold | Aggressive timing and ratio can flatten transients or raise noise |
| MP3 file compression | Smaller email, web, and review files | Encoded bitrate in kilobits per second | Lower bitrate saves space by discarding more audio information |
| Loudness normalization | Moving a complete file toward a LUFS, RMS, or peak target | One whole-program measurement and constant gain | It does not reduce the difference between loud and quiet passages |
PROCESS / THREE STEPS
How to use audio compressor
- 01
Choose the local source
Open a compatible file in the dedicated workbench at the top of this page. The browser validates and decodes it without an upload step.
- 02
Set the useful controls
Start with Podcast, Voice Level, Music Glue, or Peak Control, then adjust threshold, ratio, attack, release, knee, and makeup gain. The meter reports RMS, peak, crest factor, maximum gain reduction, and any final peak protection before export.
- 03
Process, check, and export
Run the local processor, inspect the status and preview, then save Compressed WAV · 64–192 kbps MP3 when the result is ready.
SIGNAL NOTES / VERIFIED BEHAVIOR
What this tool actually does
Clear limits are part of a useful tool. These values describe the processor currently running in this page.
The work is executed in the page through browser workers, WebAssembly, Web Audio, or WebGPU as stated.
Runtime and model assets may be downloaded, but the selected file is not attached to those requests.
The dedicated workbench exposes only formats it can actually produce in the current browser.
USE CASES / 02
Useful reasons to open audio compressor
- Podcast and voice leveling
Reduce large jumps between phrases while retaining enough attack for speech to sound natural.
- Music bus glue
Use a low ratio, slower attack, and moderate release to make peaks move together without crushing the mix.
- Smaller review files
Render the dynamics change, then choose 64–192 kbps MP3 when storage or attachment size matters more than lossless PCM.
QUESTIONS / PRACTICAL ANSWERS
Questions about this tool
Answers based on the current browser processor—not promises about a future version.
01Is my audio uploaded for processing?
No. Audio samples stay in browser memory. The page may download a codec or model asset, but it does not send the selected file with that request.
02Why can the first run take longer?
This tool uses Linked envelope follower + soft-knee compressor worker. A browser may need to download and initialize that runtime before the first operation; later runs can reuse cached assets.
03Can I preview the result before saving?
Yes. Audio-producing tools expose local result players, while analysis and transcription tools show their detected data before download.
04What happens when the browser is unsupported?
The workbench reports the missing capability instead of uploading the media or pretending that processing is still running.
05Do I need an account or install?
No. The tool opens directly in a compatible browser, requires no SoundTools account, and creates its temporary working state on the current device.
06Does an audio compressor reduce file size?
The dynamics stage changes level over time but does not inherently make the file smaller. Choose MP3 and a bitrate from 64 to 192 kbps to create a smaller lossy file; WAV remains uncompressed.
07What threshold and ratio should I use for speech?
The Podcast preset starts at −18 dB with a 3:1 ratio, while Voice Level starts at −24 dB and 4:1. Treat those as starting points and compare the original and processed players.
08What do attack and release change?
Attack controls how quickly gain reduction responds after a peak crosses the threshold. Release controls how quickly the gain returns after the signal falls back below it.
09Why does the output show peak protection?
Makeup gain can push the processed waveform above the −0.3 dBFS safety ceiling. SoundTools then lowers the complete result by the reported amount to avoid digital clipping.