Uwarp

Still image (optional)

Leave this empty for a plain dark frame. A cover image is scaled to fit 1280×720.

First run downloads FFmpeg (~25 MB) once in this browser. Conversion runs locally — no server upload.

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MP3 to video converter

Turn an MP3 into an MP4 with a still image or a plain frame. WAV, M4A, and other audio work too — free, no sign-in.

What is an MP3 to video converter?

An MP3 to video converter wraps an audio file in an MP4 so a video player can open it. This page does that audio to video job in the browser: the sound stays as it is, and the picture is a still image you add or a plain dark frame.

What you can convert

One audio file in, one MP4 out.

  1. MP3 to video: MP3 is the usual input. WAV, M4A, AAC, OGG, and FLAC convert the same way.

  2. Still image: Add a JPG, PNG, or WebP cover. It is letterboxed to 1280×720.

  3. Plain frame: Skip the image and the video uses a dark frame for the whole track.

  4. Local conversion: FFmpeg runs in this browser. The audio is not uploaded.

How to turn audio into a video

Three steps from a track to an MP4.

  1. Upload the audio

    Drop an MP3 or another supported audio file.

  2. Add a picture if you want one

    A cover image becomes the video frame. Leave it empty for a plain frame.

  3. Convert and download

    Download the MP4 when the bar finishes.

Tips

Keep the file small and the picture simple.
  • 01

    One frame per second

    The picture does not move, so the encoder writes one frame a second instead of a full motion video.

  • 02

    Cover size

    A wide image fills the frame. A tall image sits in the center with dark bars on the sides.

  • 03

    Long tracks

    A long file still has to encode the whole duration. Shorter clips finish sooner.

When this helps

Jobs that need a video file, not a new recording.

  1. Upload forms that want video: Some sites accept MP4 and reject a bare MP3. This wraps the track so the form can take it.

  2. A cover on the track: Pair the audio with one still image instead of a blank player.

  3. A shareable MP4: Send one video file that plays the original audio.

Technical details

What the MP4 contains.
Picture
H.264, 1280×720, one frame per second, yuv420p.
Sound
AAC at 192 kbps. The video ends when the audio ends.
Limits
Audio up to 200 MB. A cover image up to 15 MB, as JPG, PNG, or WebP.

Sources & References

Why an audio track can live inside a video file.
  • “A media container is a file format that encapsulates one or more media streams (such as audio or video) along with metadata, enabling them to be stored and played back together.”
    — MDN Web Docs — Media container formats

    Media container formats: The MP4 holds the original sound and a still picture in one file. developer.mozilla.org/en-US/docs/Web/Media/Guides/Formats/Containers

  • “The <video> HTML element embeds a media player which supports video playback into the document.”
    — MDN Web Docs — video element

    HTML video element: Players that expect a video file can open the MP4 this tool writes. developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements/video

Frequently Asked Questions

Quick answers about this tool—open a question to read more.