Change a Video's Audio Volume
Pick a video and a gain — its audio is boosted or cut in your browser while the picture stays untouched. Nothing is uploaded.
Make a video louder or quieter
Pick a video, choose how much to change its audio volume, and get the same clip back — louder or quieter. The picture is stream-copied (not re-encoded), so it stays byte-for-byte identical and processing is fast; only the audio track is re-encoded. Everything runs in your browser; nothing is uploaded.
How much is "a lot"?
You can set the change two ways with the Unit control:
- Decibels (dB) — the audio engineer's scale.
+6roughly doubles the perceived loudness,-6halves it.+10is a strong boost;-10a strong cut. Range: −60 to +60 dB (0 does nothing). - Factor (×) — a plain multiplier.
2is twice as loud (the same as "200%"),0.5is half,10is a big 1000% boost. Range: greater than 0 up to 16 (1 does nothing).
Worked example: a screen recording where the narration is too quiet. Load
recording.mp4, set Amount to 6 with Unit = Decibels, leave
Prevent clipping on, and you get recording-gain.mp4 — same video, audio
about twice as loud, with peaks held at 0 dBFS so the boost doesn't distort.
Prevent clipping (limiter)
When you boost, samples that were already near the maximum can be pushed past it and clip (harsh distortion). The Prevent clipping option adds a peak limiter that holds the output at 0 dBFS, so boosts stay clean. Turn it off if you want an exact linear gain (for example when measuring levels).
Notes and limits
- The video stream is copied losslessly; the output keeps the same container (mp4 → mp4, webm → webm). WebM audio is re-encoded to Opus, everything else to AAC.
- One constant gain is applied to the whole clip — this isn't a timeline/volume automation editor.
- Input and output are each capped at 25 MB (the file is processed in your browser's memory).
FAQ
Is my video uploaded to a server?
No — ffmpeg runs inside your browser tab, so the file never leaves your device.
Will boosting the volume hurt the video quality?
No. Only the audio is changed; the picture is stream-copied without re-encoding, so the video quality is identical to the original.
Can I make the video quieter or completely silent?
Quieter, yes — use a negative dB value (e.g. -10) or a factor below 1
(e.g. 0.5). To remove the audio entirely, use the Mute a Video tool
instead, which drops the audio track completely.
What's the difference between decibels and a factor?
They describe the same change on different scales. A factor of 2 (200%) is
about +6 dB; 0.5 (50%) is about -6 dB. Decibels match how loudness is
perceived; a factor is a straight multiplier on the waveform. Pick whichever is
more natural for you.
Why does the boost sometimes sound "capped"?
That's the peak limiter doing its job — it holds the loudest peaks at 0 dBFS so a big boost doesn't clip and distort. If you'd rather have an exact linear gain with no limiting, turn Prevent clipping off.
Which video formats can I use, and how big can the file be?
Anything ffmpeg can read — mp4, mov, mkv and webm are the common cases. The
output keeps the input's container and is named after the original with a
-gain suffix (e.g. clip.mp4 → clip-gain.mp4). The input and output are
each capped at 25 MB.
Developer & Automation Access
Run it from the terminal
Same engine as this page, headless — via the gizza CLI:
gizza tool video-audio-gain 'url=https://example.com/input' 'amount=6' 'unit=db' 'limiter=true'New to the CLI? Get gizza →
Open it by URL
Pre-fill and auto-run this tool with query parameters — the names match the API/CLI:
https://gizza.ai/tools/video-audio-gain/?url=https://example.com/input&amount=6&unit=db&limiter=trueMachine-readable descriptor: tool.json — title + parameters JSON Schema for agents.