Make a quiet video louder by boosting its audio up to 400%, or turn any clip down when it was recorded too hot. Only the sound is re-encoded - the picture is copied across untouched, so a boosted file looks exactly like the original. Nothing is uploaded, and there is no watermark or sign-up.
or click to select a file
🔒 Your files never leave your device - 100% private & secure
Drag a video onto the upload area or click Select Video. MP4, MOV, MKV and WebM all work, and the file stays on your device.
Choose 150%, 200%, 300% or 400% to make the video louder, or 50% and 25% to bring it down. The page shows the change in decibels so you know what you are asking for.
Click Change Volume, then download the finished file. Play it back before you send it on - if a boost sounds harsh, step down one level and run it again.
Turning up the volume slider only helps the person watching on that particular device. The moment the clip is uploaded, emailed, dropped into a slide deck or played through a hall's sound system, it is back to the level that was baked into it - and if that level was set by a phone held ten feet from the speaker, no amount of turning things up at the other end is going to feel comfortable. Raising the gain inside the file is what makes the recording travel.
Boosting works by multiplying every audio sample by a fixed factor. At 200% each sample is doubled, which is +6 dB and reads as a clearly louder track; 400% is +12 dB and is about as far as a genuinely quiet recording can usefully be pushed. The catch is that audio samples have a ceiling, and once a loud passage hits it there is nowhere further to go. VidShift clamps at that ceiling rather than letting the value wrap around, so an over-boosted peak flattens and sounds a little harsh instead of turning into a crack of digital noise. If you hear that harshness, the fix is a smaller factor, not a bigger one.
What the tool deliberately does not do is touch the picture. Only the audio track is decoded, scaled and re-encoded; the video packets are copied straight into the new container exactly as they were, so a boosted 4K clip is the same 4K clip it was before, frame for frame. That also makes the job much faster than a full conversion, because the expensive half of the work never happens. The one exception is choosing an output container that cannot carry the source's video codec - picking WebM for an H.264 file, say - and the page tells you when that is about to happen.
Everything runs locally through WebAssembly and WebCodecs. Your video is never uploaded, there is no file size cap beyond your device's available memory, no account is needed, and nothing is stamped on the output. It works the same way in Safari on an iPhone or iPad as it does on a desktop, which means a clip from your camera roll can be made louder without installing anything.
Drop the video onto this page, choose a boost - 150%, 200%, 300% or 400% - and click Change Volume. The finished file plays louder everywhere, because the new level is part of the video rather than a setting on one player. Nothing is uploaded and the picture is left exactly as it was.
Pick a factor above 100%. Each doubling is about 6 dB, so 200% is a clear step up and 400% is roughly as loud again on top of that. Start at 200%, listen to the result, and only move up if the recording is still too quiet - a boost that is too aggressive flattens the loudest moments rather than lifting them.
The video track is copied rather than re-encoded, so the picture keeps every bit of its original quality. The audio has to be decoded and written back out to carry the new level, and VidShift encodes it at the source track's own bitrate (with a sensible floor and ceiling) to keep that single generation as clean as possible. In practice the difference is inaudible next to the boost itself.
This page works in Safari on iPhone and iPad, so you can boost a clip from your camera roll without installing an app. Open the page, tap Select Video, pick the file, choose a level and save the result back to Files or Photos. Because the work happens on the phone itself, the video never leaves it - and on a long clip it will be slower than on a desktop.
Choose 50% to halve the level (-6 dB) or 25% to drop it further (-12 dB). This is the right fix for a clip recorded far too close to a speaker, or for background footage that has to sit under a voiceover. If you want the sound gone entirely, the mute tool removes the audio track instead of quietening it.
Not with this tool directly - the volume of a video playing on YouTube is a player setting, so you would raise it in the player and in your system's own volume controls. This page works on a video file you have on your device, which makes it the right choice for the other direction: boosting a quiet clip before you upload it, so viewers do not have to reach for their volume at all.
No, and the difference matters. This tool applies a fixed gain: every sample is multiplied by the factor you pick, so quiet and loud passages move by the same amount and the dynamics of the recording are unchanged. Normalisation measures the track first - its peak level, or its perceived loudness in LUFS - and then works out the adjustment needed to hit a target. VidShift does not measure your audio and does not normalise it, so choosing a level here is a judgement call you make by listening.
No. A gain boost raises everything in the track by the same amount, which means hiss, room noise and traffic get louder along with the voice you wanted. It is the right tool for a recording that is simply too quiet, and the wrong one for a recording that is noisy. It also cannot do anything about a device whose own volume is turned down - that is a playback setting, not something stored in the file.
MP4, MOV, MKV, WebM and more, including ProRes .mov files from Final Cut, Premiere or DaVinci Resolve and DTS audio from MKV and MPEG-TS rips - decoders for those load on demand when your browser cannot handle them natively. Output is MP4, WebM or MKV. Choosing an output that can carry the source's video codec keeps the picture a straight copy, and the page tells you which of the two you are about to get.