Boost Audio in
Video Online

It uses FFmpeg compiled to WebAssembly (FFmpeg.wasm), running entirely in your browser. The audio stream is re-encoded with a volume filter applied; the video stream is copied without re-encoding so the original quality and resolution are fully preserved.

No. Your file never leaves your device. All processing happens locally in your browser using WebAssembly. No data is sent to any server.

100% leaves the audio at its original level. Below 100% lowers it (50% is half as loud). Above 100% boosts it — up to 200% (twice as loud).

The tool applies a peak limiter after the boost, which softens transients that would otherwise clip. Quiet recordings sound dramatically louder without harsh distortion. Already-loud audio will sound increasingly compressed (squashed) at high boost levels, but it won't break — the limiter keeps peaks under control.

MP4, MOV, MKV, AVI, and WEBM files are supported. The output is always an MP4 file with the original video quality preserved.

There is no hard limit, but very large files (over 2 GB) may be slow or cause browser memory issues depending on your device. For best results, files under 500 MB work well.

Any modification of the audio waveform requires re-encoding the audio stream. The video stream is copied without modification, so video quality is preserved bit-for-bit. Audio re-encoding uses AAC at a sensible bitrate — quality drop is minor and rarely noticeable for speech.

Yes, completely free with no limits, no watermarks, and no sign-up required.