Add audio to video, or turn an image and audio into a video

Free. No watermark, no signup, no ads. Everything runs in your browser: your files are never uploaded. Works for mp3 to mp4.

Timelineone clock for every track
1. Image or videothe picture
2. Audio (mp3, wav, m4a...)the sound you add
OutputMP4
Appears once both files are chosen
Drop a picture or video and an audio file. The length of the result and any clipping show here once both are chosen.
Video options

Choose a video to use these. For an image, only the volume applies.

Sound
Length
Output format

The first run downloads the ~30 MB converter once; your browser then keeps it cached.

FAQ

Are my files uploaded anywhere?

No. The conversion runs on your device with WebAssembly. Nothing is sent to a server.

Is there a watermark or a paywall?

No watermark, no account, no export limit, no ads. The tool is funded by donations.

How do I add audio to a video?

Drop the video and an audio file, choose whether to replace the original sound or mix both, and click Create video.

How do I make a video from an image and an mp3?

Drop an image (PNG or JPG) and the audio. The video lasts as long as the audio.

How big can the files be?

Files over 500 MB may fail on phones; over 2 GB is not supported because browsers limit WebAssembly memory. Desktop browsers handle large files best.

Why is WebM slow?

MP4 with a still image or a copied video track is fast. WebM and re-encoded video run on one CPU thread inside your browser.