Make audio louder
Drop a video or a sound file that is too quiet, and get it back louder. The page measures the loudest moment first and raises everything until that moment just fits under the limit, so nothing is pushed past it. A video keeps its picture exactly as it was.
The result appears here once a video is open.
How to use it#
- Drop a video, an MP3, an M4A, or a WAV onto the box above, or click it to choose one.
- Leave Volume on As loud as it goes without distorting, or pick one of the Louder still choices to go further.
- Play the result in the preview, then download it. It keeps the format it came in.
Louder without distortion#
Digital sound is a run of numbers, each saying how far the speaker should move at that instant, and none of them can go past a fixed limit. Making the sound louder multiplies every number by the same amount, which changes nothing but the volume until the loudest moment reaches that limit. Past it, a plain multiply cuts the peaks flat. That is clipping, and it is heard as crackle.
So the page first finds the loudest moment in the whole file, then raises everything until that moment sits just under the limit, which audio editors call peak normalization. How far that goes depends on the one loudest moment. A quiet phone recording, or a video with its sound set low, often has a lot of room, and the Peak figure says how much. The first setting never raises a file more than 16 times, so near silence does not turn into loud hiss.
To go further, pick Louder still, at 150%, 200%, or 300% of that clean maximum. The loudest moments are then rounded off smoothly rather than cut flat, which sounds far gentler than clipping, though a big boost can make them sound a little rough.
What gets louder with it#
Everything in the sound is raised by the same amount, so hiss, hum, wind, and the noise of the room come up with the voice. A recording that sounds clean when quiet can sound noisy when loud, because the noise was always there.
One loud moment limits the whole file. A clap, a laugh, or a door closing can be the loudest thing in a recording, and the rest can only be raised until that moment fits. When the Peak figure says the file is already near the limit, but most of it still sounds quiet, Louder still is the way to raise the rest.
Videos, MP3, M4A, and WAV#
A video keeps its format and its picture, whether it is an MP4, a MOV, a WebM, or an MKV. The picture is copied as it was, and only the sound is encoded again, at 192 kbps. An MP3 comes back as an MP3 and an M4A as an M4A, so a voice memo from an iPhone, saved at the usual Compressed quality, comes back as a louder voice memo.
A WAV comes back as an uncompressed WAV at the bit depth it had, whether 16-bit, 24-bit, or 32-bit float, so nothing is lost to compression. A FLAC cannot be made louder here, because no browser can write FLAC again. Make it an MP3 with FLAC to MP3 first, then make that louder.
An older Safari, such as Safari 17, has no sound encoder a page can use, so it cannot make the sound of a video or an M4A louder, and the page says so. It can still make an MP3 or a WAV louder, for sound up to about 30 minutes long, because it has to hold the whole of it in memory at once.
Frequently asked questions#
How loud should I make it?
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Start with As loud as it goes without distorting, which is as far as the file can go without distorting. If one loud moment holds it back and the rest is still too quiet, pick Louder still at 150% or 200%, and listen to the loudest part of the result. 300% suits speech that was recorded far too quietly.
Does making audio louder lower the quality?
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Raising the volume changes nothing else until the loudest moment reaches the limit, and the default setting stops just short of it. The sound is then encoded again, at 192 kbps for a video, an MP3, or an M4A, which is very hard to hear. A WAV is written uncompressed, at the bit depth it came in. Any hiss or hum in the recording gets louder along with the rest.
Why is it only a little louder?
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The file has at least one moment that is already loud, and the default setting will not push that moment past the limit. The Peak figure says how loud that moment is. Pick Louder still to raise everything further, with the loudest moments rounded off. Hearing plays a part too: doubling the level sounds clearly louder, but nowhere near twice as loud.
Is this the same as normalizing audio?
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The first setting is peak normalization: the loudest moment is brought up to just under the limit. It does not match how loud different files sound, as the loudness targets that streaming services use do, so two files made louder here can still sound unequal. For making one quiet file louder, that difference does not matter.
Can I make a video louder on an iPhone?
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Yes, in Safari on a current iOS. Tap the box, choose Photo Library, and pick the video. iOS hands the page a converted copy rather than the original, usually as H.264. The result is saved in the Files app, where it shows under Recents, and Share, then Save Video, puts it in Photos. An older iOS cannot make the sound of a video louder, though it can still do an MP3 or a WAV.
Can I make only the voices louder?
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No. Voices, music, and background noise are mixed together in the sound track, so they all get louder by the same amount.
Is my file uploaded?
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No. The file is read, made louder, and written again inside this browser tab, and the result is handed straight to your downloads. Nothing is sent to a server.