Rescue the recording nobody can hear
It's a universal disappointment: the lecture recorded from the back row, the interview where the phone sat too far away, the voice memo whispered to avoid waking the house. Playback volume is maxed and it's still inaudible. Turning the knob can't fix it — but re-rendering the audio itself can. This tool multiplies the actual sample values of your recording (10% to 300%), permanently raising — or lowering — its baked-in loudness, and saves the result as a new MP3 or WAV.
How to change audio volume
- Drop your audio file.
- Set the volume slider: 200% doubles the level — the right starting point for most quiet recordings.
- Choose MP3 or WAV output and click Apply & download.
- Audition the built-in preview; adjust and re-run if needed.
The one enemy: clipping
Digital audio has a hard ceiling. Samples pushed beyond it don't get louder — they get flattened, and flattened waveforms sound like crackling, fuzzy distortion that no tool can undo. The risk depends entirely on your recording's headroom: a genuinely quiet memo has lots of room and takes 200–300% gracefully; a recording that's already moderately loud may distort at 150%. The safe procedure is built into the workflow: boost, listen to the preview (especially the loudest moments — laughs, plosives, applause), and if you hear crackle, re-run lower. Going up in two gentle steps beats one heroic leap.
Turning it down is a feature too
Below 100%, the slider becomes an attenuator. Quieting an over-hot recording before it goes into a video edit, making background music sit politely under narration, or standardising a batch of clips to similar levels — reduction is distortion-free at any setting (you're moving away from the ceiling), making it the risk-free direction.
Realistic expectations
- Noise rises with voice: boosting amplifies everything, hiss and hum included. A 300% boost of a noisy source is a louder noisy source.
- Inaudible stays inaudible: if speech is genuinely buried below the noise floor, gain can't separate it — that's restoration-software territory.
- Chain smartly: trimming first (Audio Trimmer) means boosting only the useful part; export WAV between steps, MP3 at the end.
- Phone-speaker test: if it's destined for voice messages, preview on the worst speaker you own — that's where quiet recordings die.
Two hundred percent and one click stand between “sorry, can you email a transcript?” and a recording people can simply hear.
Quick reference
| Property | Detail |
|---|---|
| Input | Any browser-decodable audio |
| Range | 10% (quiet) to 300% (triple) |
| Method | True sample re-rendering, not a playback trick |
| Risk above ~150% | Clipping on already-loud sources — preview! |
| Reduction | Distortion-free at any level |
| Output | MP3 or WAV + instant preview |
| Processing | 100% in-browser, no upload |
Frequently asked questions
Why does my boosted audio crackle, and how do I fix it?
You've hit clipping — samples pushed past digital maximum get flattened into distortion. Re-run from the original at a lower setting (try 150% instead of 250%). Distortion can't be removed after the fact, which is why the preview step matters.
How much louder can I safely go?
It depends on the recording's headroom. Genuinely quiet memos often take 200–300% cleanly; moderately-loud material may cap at 120–150%. The honest answer is: boost, audition the loudest passages, adjust.
Will boosting reduce background noise?
No — gain raises voice and noise together, preserving their ratio. It makes recordings audible, not cleaner. Noise reduction is a different process requiring dedicated software.
Can I use this to quieten music for a voice-over?
Yes — set the slider below 100% (e.g. 40–60%), export as WAV, and lay it under your narration in any video editor. Attenuation introduces no distortion whatsoever.