Convert MP3 to MP4
An MP3 has no picture, so a video needs one. Add a photo or leave the screen black, and get an MP4 that plays anywhere. It is made on your own computer, so the sound is never uploaded.
- Never uploaded
- No size limit
- No sign-up
- Free
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Quick answer: To convert MP3 to MP4, drop the MP3 into the tool at the top of this page and, if you like, add a picture. Press "Make video" to get an MP4 with your sound over a black screen or your picture. It happens in your browser, so the file is never uploaded. It is free, with no sign-up and no watermark.
Updated
How it works
- Drop your sound fileMP3, WAV, M4A, FLAC, OGG and more. It stays on your computer.
- Add a picture, if you likeWithout one the screen stays black. A picture is shown for the whole sound.
- Download the MP4A video that plays on every phone, computer and video site.
A picture is what turns sound into a video
An MP4 video needs a picture, and an MP3 has none, so the tool puts one on the screen for the whole length of the sound. Without a picture it is plain black. With a photo, such as a cover or a logo, that photo stays on screen. Pictures taken on a phone come out the right way up.
Choose how the picture fits: fit puts it in a 1280×720 frame with bars where it does not fill the screen, and own shape makes the video the shape of the picture.
How big the video is
The picture barely adds to the size. Our 20-second sample came out at 322 KB with a black screen, nearly all of it the sound. A photo added about 80 KB for the same 20 seconds. The black picture is 1280×720 at one frame a second, which is why the file stays small.
Do you need an AI tool to turn an MP3 into a video?
Not for this. Searches for "MP3 to MP4 AI" are usually after tools that invent moving pictures to go with a song. This page does not do that: it puts your sound and one picture of your own into a video file, on your computer, and adds nothing you did not choose.
Measured, not promised
Measured on 21 Oct 2026 in Chrome on a 2019 Intel MacBook (an older laptop) with a 20-second sample. Newer computers are faster; real files vary. More results.
Why your audio never leaves your computer
Your audio is converted by your own computer, inside this tab, and never uploaded. That is why there is no length limit and no sign-up. How it works.
Questions
Can I use my own picture?
Yes. Add a photo before you press "Make video". It stays on the screen for the whole sound.
Will the sound change?
No. Your sound goes into the video as it is, or is saved in the form every device plays.
Does it work for WAV or M4A?
Yes, any common sound file works. For WAV there is a page of its own: WAV to MP4.
Is my file uploaded?
No. It is converted inside this browser tab and saved straight back to your computer.
Can I use a video file?
Yes. Drop a video and you get its sound.