Make audio louder or quieter
Rescue a recording that came out too quiet to hear, or bring a set of files to a consistent level. The actual level is measured before and after, so you can see what changed rather than guess.
- Never stored
- No queue, no waiting
- No signup, no watermark
How it works
Add your file
Any audio. Its level is measured as it loads — the loudest moment and the average — so you can see how quiet it really is.
Choose how much
Let it level the file automatically, which lifts the loudest moment to just under the ceiling, or set the change yourself in decibels.
Download the result
The result reports the measured peak before and after, and tells you if anything hit the ceiling.
One number applied to everything
This multiplies the whole recording by a single factor. Everything gets proportionally louder or quieter, and the relationship between the loud and quiet parts is exactly as it was. That is the important limit to understand: a recording where one speaker is close to the microphone and another is across the room will still have one loud voice and one faint one afterwards — both simply moved together. Evening out a recording is compression or levelling, a different operation that changes the loud and quiet parts by different amounts, and it is not what this does.
Turning sound up has a hard ceiling that turning it down does not. Digital audio has a maximum value, and pushing a waveform past it flattens the peaks into a straight line — clipping, which sounds like harsh crackling distortion and is permanent. So a recording already close to the ceiling has very little room to move, whatever you ask for, and a quiet one has plenty. There is no true-peak limiter here to catch what goes over, which is exactly why the tool is conservative about how far it will go.
A quiet recording is also quiet for a reason, and turning it up brings the reason with it. Hiss, hum, air conditioning and room noise all rise by the same amount as the voice, because nothing here distinguishes between them. The result is louder and no clearer. The fix for a badly recorded file is noise reduction before amplification, not more gain.
On the file itself: a lossy file has to be decoded, scaled and encoded again, which costs a generation of quality — so adjusting the volume of an MP3 twice is worse than getting it right once. A WAV is scaled losslessly. Worth knowing that many players and streaming platforms apply their own loudness normalisation on playback, so a file you carefully made louder may simply be turned back down at the other end.
When you want something else
For MP3 specifically there is a genuinely better method that no browser can offer. mp3gain adjusts playback volume by changing a field in each frame rather than re-encoding the audio, so the change is completely lossless and fully reversible — and it can match a whole album to a consistent loudness in one pass. For a music library this is the right tool and this page is not.
For broadcast or podcast delivery, loudness is measured rather than guessed. ffmpeg -i in.wav -af loudnorm=I=-16:TP=-1.5:LRA=11 out.wav normalises to the standard most podcast platforms expect, with a true-peak limit that prevents the clipping described above. And for evening out a variable recording, Audacity has compression, levelling and noise reduction, is free, and shows you the waveform while you work.
Frequently asked questions
What does "level it automatically" actually do?
It measures the loudest moment in the whole recording, works out how far that is from the ceiling, and lifts everything by that amount. The result is as loud as the file can be without distorting. This is normalising, and it is the right answer for a recording that is simply too quiet throughout.
Why can't I just turn it up more?
Because digital audio has a hard ceiling. Past it, the peaks are cut flat and the sound distorts — and unlike a volume knob, that damage is written into the file. We hold anything that would go past the ceiling rather than letting it wrap round into noise, and tell you when it happened so you can use a smaller increase.
My recording is quiet in places and loud in others. Will this fix it?
Not really. Turning the whole file up moves the quiet parts and the loud parts together, so the difference between them stays. Evening that out is compression in the dynamic-range sense — a different job, and one this tool does not do yet. What this fixes is a recording that is uniformly too quiet.
Does changing the volume lose quality?
It has to decode and re-encode, so for an MP3 or M4A there is one lossy pass — the result says so. A WAV or FLAC comes back as a WAV with nothing lost. If you are going to do several things to a recording, convert to WAV first and encode once at the end.
What do the decibel numbers mean?
They are measured from the ceiling downwards, so 0 dB is as loud as a file can be and every number is negative. A recording peaking at −20 dB is very quiet; one peaking at −1 dB is about as loud as it can safely get. Adding 6 dB roughly doubles the perceived loudness.
Is my file stored anywhere?
No. The measurement and the change both happen here, so a private recording is never stored.
Good to know: This changes the whole file by one amount; it cannot even out passages that are loud and quiet in turn. Lossy files must be re-encoded, which costs a little quality. There is no true-peak limiter, so material already close to the ceiling has little room to move.
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