Fade Video Audio In or Out
Pick a video and fade its sound in, out, or both — the picture is copied untouched and nothing is uploaded.
Fade the sound in or out without changing the picture
Use this tool when a video's audio needs a softer entrance, a cleaner ending,
or both. Choose a fade-in length, a fade-out length, or set one side to 0 to
skip it. The video stream is copied without re-encoding, so the picture stays
untouched; only the audio is re-encoded because its volume curve changes.
Everything runs in your browser and nothing is uploaded.
Worked example: load intro.mp4, set Fade in to 3 seconds and Fade
out to 4 seconds. The result starts from silence, reaches full volume over
three seconds, keeps the picture unchanged, and fades the sound down over the
last four seconds.
How the fade is applied
- Fade in ramps audio from silence to full volume starting at the beginning.
- Fade out ramps audio from full volume to silence at the end. Internally it uses a reverse/fade/reverse ffmpeg chain, so it does not need to know the video's duration before processing.
- A value of
0skips that side; both values at0are rejected because the output would be unchanged.
Notes and limits
- Each fade can be from
0to30seconds, in half-second steps on the page. - The output keeps the same container where possible (
mp4→mp4,webm→webm). WebM audio is encoded as Opus; other common video containers use AAC. - This is audio-only. It does not fade the picture to black or crossfade between clips; use a video-picture fade or editor for that.
- Input and output are each capped at 25 MB because ffmpeg runs in the browser.
FAQ
Will this change the video quality?
No. The picture stream is copied without re-encoding, so the visual quality is preserved. Only the audio track is decoded and re-encoded to apply the fade.
Can I fade only the ending?
Yes. Set Fade in to 0 and set Fade out to the number of seconds you
want. You can also do the opposite for a fade-in-only result.
Why is fade-out allowed without entering the video duration?
The ffmpeg plan reverses the audio, applies a fade-in to that reversed stream,
and reverses it back. That creates an end fade without needing to calculate
duration - fade_length in advance.
What happens if both fade lengths are 0?
The tool rejects that as a no-op. Set at least one fade length above zero so the processed video is meaningfully different from the input.
Can this fade the image to black too?
No. This tool deliberately changes only the audio while copying the picture. A picture fade or timeline crossfade is a different video-editing operation.
Developer & Automation Access
Run it from the terminal
Same engine as this page, headless — via the gizza CLI:
gizza tool video-audio-fade 'url=https://example.com/input' 'fade_in=3' 'fade_out=3'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-fade/?url=https://example.com/input&fade_in=3&fade_out=3Machine-readable descriptor: tool.json — title + parameters JSON Schema for agents.