Increase video volume
Turn up a quiet video without re-encoding the picture, on your own device.
- Nothing is uploaded
- Works offline after first use
- Open source
- No watermark · limit is your device’s memory; phones hold less
Make a quiet MP4, MOV or WebM video louder in your browser. The picture is copied untouched, peaks stay clean. It is free, needs no account and adds no watermark, and your files are not uploaded: everything runs in your browser on your device. The size limit is your device’s memory, and phones hold less; give the page a short while after your first run to save itself for offline use, and then it works offline.
Done
Open the network tab. Your files never appear in it.
Add files and run the tool to see every request this tab makes.
Your files are processed on this device and never sent to a server. Reload the page to clear everything from memory.
Phone videos filmed from across a room, screen recordings with a quiet microphone and old camera clips often play too softly. This page turns the sound up by the amount you choose and puts it back with the original picture, which is copied as it is, so the video looks exactly the same and the job is quick.
A limiter keeps the loudest moments from clipping, so a +10 or +15 dB boost stays clean. Nothing is uploaded, there is no watermark, and the size limit is your device’s memory (phones hold less).
Pick the amount by how quiet the video is now. +6 dB helps a clip that is a bit soft next to others; +10 dB suits a phone video where people speak from a few metres away; +15 or +20 dB is for a screen recording made with the laptop microphone turned low. Try one clip first, listen, and run the rest. If you are gathering clips from different phones and want them all at the same level, choose Normalize under Change instead of a fixed amount.
A few things to expect. An iPhone MOV or an MKV comes back as an MP4 with the same picture; a WebM made with the VP8 codec stays a WebM so it still plays in Safari. The Save as list only affects audio files; videos always keep their picture and get new sound. Turning the sound up also lifts wind, hum and room noise, so a boost makes speech louder but not cleaner.
How it works
- Drop one or more videos, or tap to pick them.
- Choose how much louder: +10 dB is about twice as loud. Or pick Normalize.
- Run it. Each video downloads when it is ready.
In your browser, not on a server
Your browser decodes the sound with its own audio decoders. Every sample is multiplied by the gain you chose (or the gain that brings the gated loudness to about −14 LUFS), then a look-ahead peak limiter turns down only the moments that would pass −1 dBFS, easing in over 5 ms and out over 150 ms. The file is written again in your tab: MP3 by LAME in WebAssembly, WAV and FLAC by code in this site, M4A and OGG by the browser’s own encoders. For a video, Mediabunny (MPL-2.0) copies the picture packets unchanged and adds the new sound.
Compared with upload-based tools: Online volume boosters upload the recording or video, cap the file size, and often just multiply the samples so loud parts clip and crackle. Here nothing leaves your device and the limiter keeps boosted sound clean.
Verify it yourself. Give the page a short while after your first run to save itself for offline use, then turn off Wi-Fi or switch to airplane mode and run the tool again. Or open your browser's developer tools (F12, or Cmd-Option-I on a Mac), pick the Network tab, and watch it while you convert. The panel above does the same count for you.
Questions
Is the picture re-encoded?
No. The video packets are copied into the new file unchanged. Only the sound is decoded, turned up and encoded again (AAC in MP4, Opus in WebM).
How much louder is +10 dB?
To the ear, about twice as loud. +6 dB is clearly louder, +3 dB only a little. Because the limiter holds the loudest moments at the same ceiling, a big boost mostly raises the quiet parts, such as speech in between louder sounds, which is usually what a quiet video needs.
Can I make a video quieter instead?
Yes. The How much list also has −3, −6 and −10 dB, which is about half as loud. That helps when a clip with loud music or a shouting crowd sits next to quieter ones in an edit, or when a video's sound is too harsh on a phone speaker.
What if my video has no sound at all?
Then there is nothing to boost and the page tells you the file has no sound to change. If the video should have sound, check that the recording app had microphone access. To give a silent video a soundtrack, use Add audio to video.
Is the file uploaded anywhere?
No. There is no server in this process. The page is a static file and the work is done by code running inside your browser tab. Give the page a short while after your first run to save itself for offline use; then you can turn off Wi-Fi and it still works.
More video and audio tools
Volume booster
Boost a quiet recording, turn down a loud one, or even out a batch. Done on this device, never uploaded.
Compress video
Make a video a fraction of the size, or fit it under a limit like 10 MB for Discord or 25 MB for email. It is compressed on this device and never uploaded.
Video to MP4
Turn MOV, MKV and WebM files into MP4s that play everywhere. Converted on this device, never uploaded.
Trim video
Cut a clip out of a longer video without uploading it. Most cuts take seconds and keep the original quality.
Other conversions
Guides
- How to increase audio volumeSimply turning up a quiet recording clips the loud parts before the quiet parts get loud enough. Here is a better way, and a free tool that does it without uploading the file.