Adjust Audio Volume

Why is volume measured in decibels?

Human hearing is logarithmic — we perceive ratios, not absolute steps — so audio gain uses decibels, a logarithmic unit, to match. The practical rules of thumb are worth memorising: +6 dB doubles the amplitude and −6 dB halves it, but perceived loudness doubles at about +10 dB and halves at about −10 dB. A +3 dB nudge is a clearly audible lift; +10 dB is a big shove. This is why a small dB number can make a large difference, and why you rarely need more than a handful of decibels to fix a recording.

What is clipping and how do you avoid it?

Digital audio has a hard ceiling at 0 dBFS. If a boost pushes the loudest peaks above it, they are flattened against that ceiling — that is clipping, and it sounds like harsh, crackly distortion that cannot be undone. This tool applies the gain you set without measuring the peak or limiting the result, so the judgement is yours: boost in small steps, listen for crackle, and back off if you hear any.

When to adjust gain versus normalize?

Adjusting gain is a manual, blunt instrument — you decide the exact dB and it applies everywhere equally. That is perfect when you know precisely what you want ("this is 4 dB too quiet"). Normalizing is automatic — the tool measures the loudness and works out the gain for you, aiming at a fixed −16 LUFS. Reach for gain when you are in control of the number, and normalize when you want a consistent result across many files.

There is a quality dimension too, and it is reassuring. Applying gain in the digital domain is a clean multiply: it adds no noise when you turn a file down, and none when you turn it up until the moment peaks hit the ceiling. The only audible cost ever comes from clipping at the top, never from the gain operation itself — which is exactly why a modest, well-judged boost is completely transparent and why clipping is the one thing worth watching for. One practical note: WAV and FLAC files stay lossless, but MP3, M4A and OGG files are re-encoded at 192 kbps after the gain, as with any edit to a lossy file.

Is the file uploaded to change its volume?

No. The gain is applied by ffmpeg.wasm in your browser; the file is read, scaled and returned locally with no network request. Check it yourself in DevTools → Network — adjusting the volume sends nothing. Private interviews and unreleased mixes stay on your device.

Related audio and video tools

For a consistent target across a whole library, use normalize audio. To ease the very start and end rather than the whole level, add a fade in and out. Compressing after boosting? Do it with compress audio. And if the loud or quiet track lives inside a movie, extract the audio from the video first, then adjust it here.