Open a video, drag the volume up to 400% (or down to make it quieter) and listen to the result live. A built-in limiter keeps loud parts from crackling, and the boosted video is created on your device with no upload and no watermark.
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Level
CLIP
200%+6.0 dB
0%100%200%300%400%
Analyzing the soundtrack…
Your boosted video
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How to use the Video Volume Booster
Choose a video by dropping it on the box or clicking to browse (MP4, WebM or MOV).
Set the volume with the slider or a preset such as 200%. Press play to hear the result and watch the level meter.
Try the automatic buttons: Max without clipping raises the volume until the loudest peak just fits; Make it loud pushes the average level up and lets the limiter catch the peaks.
Keep the limiter on when boosting above 100% so loud moments don't distort.
Press Boost & export video, wait while the video plays through once, then press Download video.
Volume percent and decibels
The volume slider multiplies every audio sample by the same factor. Loudness is usually measured in decibels, where the change is dB = 20 × log10(percent ÷ 100). Doubling the amplitude adds about 6 dB, which most people hear as clearly louder but not "twice as loud" (that takes roughly +10 dB).
Digital audio has a hard ceiling called 0 dBFS (full scale). If a boosted sample goes past it, the top of the waveform is cut flat, which you hear as crackle or harsh distortion. The limiter watches the signal after the volume change and, only when a peak would cross the ceiling, turns that moment down within about a millisecond, then lets go again. Quiet and normal passages are left untouched, so the overall result is louder without clipping.
Find max without clipping reads the whole soundtrack, finds its single loudest sample and sets the volume so that peak lands at −1 dBFS. No limiting is needed at that setting.
Make it loud aims the average (RMS) level at about −14 dBFS, similar to typical online video, but never asks the limiter to reduce peaks by more than about 6 dB.
The level meter shows the output level while the preview plays; the CLIP light turns red if samples would be cut off.
Tips for better sound
Boosting raises everything, including background hiss and hum. If a recording is noisy, clean it with a noise reducer first and boost afterwards.
If the speech is quiet but music or effects are loud, a plain volume boost hits the limit quickly. Use Make it loud with the limiter, or lower the music in an editor.
Use the Original / Boosted switch to compare at the same position before exporting.
For a quick sound-only fix, Download audio (WAV) renders the boosted soundtrack in a few seconds without re-encoding the picture.
Frequently asked questions
How do I make a quiet video louder?
Open the video, move the volume slider above 100% (200% doubles the amplitude, about +6 dB) and keep the limiter switched on. Press Boost & export video and download the result. The picture stays the same; only the soundtrack is amplified.
Will boosting the volume cause distortion?
Without protection, any sample pushed past full scale is clipped and sounds harsh. The built-in limiter lowers only those loud peaks for a split second so they stay just below 0 dBFS, which keeps speech and music clean up to roughly +6 to +9 dB of boost. Very large boosts on already loud audio will still sound squashed.
What does 200% or 400% volume mean in decibels?
Volume percent is an amplitude multiplier. 200% is ×2, or +6.0 dB; 300% is +9.5 dB; 400% is ×4, or +12.0 dB. 50% is −6.0 dB. The formula is dB = 20 × log10(percent ÷ 100).
Can I lower the volume of a video too?
Yes. Move the slider below 100%. 50% halves the amplitude (−6 dB) and 0% saves the video with silence. To remove the audio track entirely, use the Mute Video tool.
Why does the export take as long as the video?
Browsers can only encode video in real time with the MediaRecorder API, so the video plays once in the background while the picture and boosted sound are recorded. A 2 minute video takes about 2 minutes. Keep the tab open and visible. If you only need the sound, Download audio (WAV) is almost instant.
Will I get MP4 or WebM?
Chrome, Edge and Safari can record MP4 (H.264 with AAC audio), which plays almost everywhere. Firefox records WebM (VP8/VP9 with Opus audio), which plays in browsers, VLC and on YouTube. The Format list only shows what your browser supports.
Is my video uploaded?
No. The video is decoded, boosted and encoded on your own device. Nothing is sent to a server, and the file never leaves your computer or phone.
Are all the tools on FreeToolCabin tested for quality and accuracy?
Yes! Every tool on our site undergoes automated Q/A testing in real browser environments to ensure high precision, correct output, and zero errors. If you happen to spot a bug or have a suggestion, please contact us at [email protected] and our team will review it right away.