Louder by exact decibels
Add anything from 0.5 to 30 dB. +3 dB is the safe default; +6 dB is about twice as loud.
Increase Video Volume
Make videos louder, right in your browser. Choose how many decibels to add or remove, or let the tool find the maximum volume that does not distort. Only the sound is re-encoded; the picture is copied as it is, so quality stays the same and it takes seconds. Up to 10 videos at a time, and nothing is ever uploaded.
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Drop videos here or click to choose
MP4, MOV, AVI, MKV, WebM, WMV, FLV, 3GP… · up to 10 videos · max 500 MB each
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Everything happens in your browser: your videos are never uploaded.
Main features
A volume booster for videos that runs entirely on your device and never touches the picture.
Automatic maximum
The tool measures the loudest peak of the soundtrack and raises the whole video to the maximum level that still does not clip.
The picture is not re-encoded
Only the audio is processed; the video stream is copied byte for byte. Same resolution, same quality, and it takes seconds even for a large file.
Quieter too
Move the slider below zero to lower the volume of a video that plays too loud, down to −20 dB.
Nothing is uploaded
FFmpeg runs inside your browser, so your videos never leave your computer or phone.
Up to 10 videos at once
Apply the same change to a whole batch and download the results one by one or as a .zip.
All common formats
MP4, MOV, M4V, AVI, MKV, WebM, WMV, FLV, MPEG, 3GP, TS and more. The result keeps the original container whenever possible.
Free, no account, no watermark
Process as many videos as you like. We only ask you to share the website if you find it useful.
Questions and answers
Is it really free?
Yes. There is no account, no limit on the number of videos and no watermark. The website is supported by ads.
Are my videos uploaded to a server?
No. Everything is processed by your browser with FFmpeg compiled to WebAssembly. You can even disconnect from the internet once the page has loaded.
How many decibels should I add?
Start with +3 dB, which is clearly audible but safe for most videos. +6 dB sounds about twice as loud, +10 dB about three times. If you do not know how much headroom the soundtrack has, choose "Automatic": it raises the volume exactly to the point where the loudest peak reaches the maximum.
Does the video lose quality?
The picture does not: the video stream is copied without re-encoding. Only the audio is decoded, changed and encoded again, by default at the same bitrate as the original, which keeps the loss negligible. Pick 256 or 320 kbps if you want the best result.
The sound is distorted. What happened?
Digital audio has a hard ceiling: if the soundtrack was already loud, adding several decibels pushes the peaks over it and they get flattened (clipping). Use fewer decibels, or the "Automatic" mode, which never goes past the ceiling.
Which formats are supported?
MP4, M4V, MOV, AVI, MKV, WebM, WMV, ASF, FLV, F4V, MPG, MPEG, VOB, TS, MTS, M2TS, 3GP, OGV and more. The output keeps the original container and video stream; the audio is re-encoded with the codec that container expects (AAC for MP4/MOV/MKV, Opus for WebM, MP3 for AVI…). For the few containers that cannot be written this way, the tool falls back to MP4.