Add music to a video
Put a song under a clip for a reel, a slideshow or a school project, without uploading anything.
- Nothing is uploaded
- Works offline after first visit
- Open source
- No watermark · limit is your device’s memory; phones hold less
Add a song to a video in your browser. MP3, WAV or M4A, looped or faded to fit, over or instead of the original sound. It is free, needs no account and adds no watermark, and your files are not uploaded: everything runs in your browser on your device. The size limit is your device’s memory, and phones hold less; give the page a short while after one visit to save itself for offline use, and then it works offline.
Done
Open the network tab. Your files never appear in it.
Add files and run the tool to see every request this tab makes.
Your files are processed on this device and never sent to a server. Reload the page to clear everything from memory.
Holiday clips, a slideshow exported from your phone, a product demo: a song makes them watchable. Drop the video and the song, and Stayput lays the music under the picture, cut and faded at the end of the video or looped if the song is short.
To keep what people say in the clip, choose to keep the video’s sound: the music then plays at half volume underneath.
The picture is copied untouched, so there is no loss of quality and no waiting for a re-encode. Nothing is uploaded, and there is no watermark.
The song always starts on the first frame of the video, from the beginning of the track. If the part you want is a chorus a minute in, cut the song first with Trim audio so it begins there, then add it here. When the song is longer than the clip, it is cut at the end of the video and, with “Fade the sound out at the end” ticked, faded over the last second and a half so it does not stop mid-note.
When the song is shorter than the video, it starts again from the top. That works well for loops and instrumental beds, but a song with a clear ending can jump audibly where it restarts. Untick “Loop the sound if it is shorter than the video” and the music simply ends, leaving the rest of the clip silent, which suits a slideshow that has a quiet end card. For a clip that has no sound of its own, both choices under “The video’s own sound” give the same result.
How it works
- Drop a video and a song.
- Replace the sound, or keep it with the music underneath.
- Press Add audio and save the video.
In your browser, not on a server
Mediabunny (MPL-2.0) reads the MP4, MOV, WebM or MKV video in your tab and copies its picture packet by packet into a new file, with no re-encoding. The sound file is decoded by your browser, looped or cut and faded to the length of the video, mixed with the video’s own sound if you asked, and encoded as AAC (or Opus) by your browser (WebCodecs).
Compared with upload-based tools: Online editors upload the video and the song to a server, re-encode the whole picture, cap free exports and often add a watermark. Here nothing leaves your device and the picture is not touched.
Verify it yourself. Give the page a short while after one visit to save itself for offline use, then turn off Wi-Fi or switch to airplane mode and run the tool again. Or open your browser's developer tools (F12, or Cmd-Option-I on a Mac), pick the Network tab, and watch it while you convert. The panel above does the same count for you.
Questions
Can I use any song?
The tool works with any MP3, WAV, M4A, OGG or FLAC file on your device. Whether you may post the result is a copyright question: platforms like Instagram and TikTok may mute videos with commercial music, so royalty-free music is the safe choice for public posts.
Can I add music to a video on my phone?
Yes, in the phone's browser. Tap the drop zone and choose the video from your photo library, then tap again and pick the song from Files. Tracks downloaded inside Apple Music or Spotify are protected and cannot be picked; use an MP3 or M4A you own or have downloaded from a royalty-free library. The finished video saves to your downloads.
What format is the video with music?
An MP4 in almost every case, with the picture copied as it was and the song encoded as AAC where the browser can write it. The one exception is a WebM with VP8 video, which stays a WebM, because VP8 inside an MP4 does not play in Safari. The file name is the video's name with -with-audio added.
Can I choose where the music starts or how loud it is?
There is no start point or volume slider. The music starts with the video, at full volume when it replaces the video's sound and at half volume when it plays under the clip's own sound. To start later in the song, shorten the song first with Trim audio so it begins at the part you want.
Is the file uploaded anywhere?
No. There is no server in this process. The page is a static file and the work is done by code running inside your browser tab. Give the page a short while after one visit to save itself for offline use; then you can turn off Wi-Fi and it still works.
More video and audio tools
Add audio to video
Put music or a voice-over on a video, or replace its sound. The picture is copied as it is, and nothing is uploaded.
Mute video
Take the sound out of a video, in seconds and without re-encoding. The video never leaves this device.
Resize video
Change a video’s resolution, from 4K down to 240p or to a width and height you choose. Resized on this device, never uploaded.
Rotate video
Turn a sideways or upside-down video the right way up, or mirror it. Done on this device, never uploaded.
Other conversions
Guides
- How to add music to a videoAdding a soundtrack to an existing video is not something most camera rolls support directly. Here is what does the job.