Put Your Own Sound on a Clip
You shot a 30-second product clip on your phone. The footage is great. The audio? A dog barking next door and someone slamming a car door. Happens all the time. What you actually want is a clean music bed or the voiceover you recorded separately at your desk.
That’s the job here. Hand it one video and one audio file, and it swaps the video’s existing sound for the audio you uploaded. The picture stays untouched.
How the Swap Works
Pick the video first, then the audio. Once both slots are filled, the Add Audio button wakes up. FFmpeg on the server muxes your audio onto the video stream and re-wraps everything as MP4.
Here’s the one rule worth knowing: the output runs only as long as the shorter of the two files. Got a 20-second clip and a 3-minute song? The result is 20 seconds, music cut wherever the video ends. Flip it, a 2-minute video with a 40-second jingle, and you’ll get 40 seconds of finished video. Trim your audio ahead of time if you need an exact match.
Steps
- Choose your video.
- Choose the audio file you want on it.
- Hit Add Audio.
- Download the MP4.
Where People Reach for This
Background music on social clips. A silent or noisy reel feels dead. Drop a licensed track underneath and it suddenly has energy. Instagram, TikTok, YouTube Shorts, same idea everywhere.
Voiceover narration. You recorded a clean walkthrough on a USB mic while the screen capture ran muted. Marry the two and your tutorial sounds professional instead of echoey.
Killing bad on-set audio. Wind, traffic, an AC unit humming the whole take. Replace the original track entirely rather than fighting it with noise reduction.
Slideshow-style videos. You exported a photo montage with no sound. A gentle audio bed turns a flat sequence into something people actually watch to the end.
Localized versions. Same footage, different language. Record the new voiceover and attach it without touching the visuals.
Need to strip sound out completely instead of replacing it? The Video Mute tool does exactly that. Want to stitch several clips together first, then score the whole thing? Run Merge Videos, then come back here.
Good to Know
Your files upload to the server, get processed, and the temporary copies are wiped automatically about an hour later. Nothing sticks around. The output is always MP4, which plays on basically anything: phones, browsers, TVs, editing apps.
One thing to keep in mind. This replaces the audio, it doesn’t layer it on top of existing sound. If you wanted the original dialogue plus background music mixed together, that’s a different operation. Here, the uploaded audio becomes the soundtrack, full stop.
FAQ
What audio formats can I upload?
MP3, WAV, AAC, M4A, OGG, the common ones all work. FFmpeg handles the decoding on its end, so you don’t need to convert the audio first.
Does my original video audio stay in the file?
Nope. The uploaded audio replaces it entirely. If you need the original sound, keep a copy of your source video before processing.
Why is my output shorter than my video?
Because your audio file was shorter. The result trims to whichever of the two ends first. Lengthen the audio or shorten your expectations, your call.
Is the video re-encoded?
The container is rebuilt as MP4 and the audio is encoded to fit, but the tool keeps quality loss minimal. Visually you won’t spot a difference.
How big a file can I send?
Up to 100 MB. Larger clips take a little longer to come back since the muxing runs server-side.