How to convert MP3 to MP4
- 1
Click Choose files and select your audio file (MP3, WAV, M4A, AAC, OGG or FLAC).
- 2
Optionally add one image (JPG, PNG or WebP) in the same selection — it's shown for the whole video. Without one, a plain background is used.
- 3
Click Convert. The MP4 downloads automatically when it's ready.
Why turn audio into a video?
Many platforms don’t accept audio files at all. YouTube, Instagram, TikTok, Facebook and X expect a video — so musicians, podcasters, teachers and speakers routinely publish their audio as an MP4 with a single image. Typical uses:
- Music — publish a track with its artwork on YouTube.
- Podcasts — post full episodes or highlights on video platforms.
- Voice messages and recordings — share them where only videos can be posted.
- Lectures and sermons — put the audio online with a title card.
- Messaging apps that handle videos better than audio attachments.
Choosing the cover image
The image is displayed for the whole duration, so it’s worth a moment’s thought:
| Platform | Suggested image |
|---|---|
| YouTube | 16:9 landscape, 1920 × 1080 px |
| Instagram feed | Square, 1080 × 1080 px |
| TikTok, Reels, Shorts | Vertical 9:16, 1080 × 1920 px |
Include the title and artist or show name in the image itself, since some players show the video without the description. If your picture is too large or in another format, prepare it first with Resize image.
Common problems
- The image is cropped or has borders. The video takes the shape of your image. Prepare it at the shape of the platform you’re targeting (16:9, 1:1 or 9:16).
- The MP4 is larger than the MP3. The audio is kept and a video track is added, so a somewhat larger file is normal.
- The conversion takes a while. Every second of audio becomes a second of video; for an hour-long podcast, use a computer.
Converting the other way
Got a video and only need its sound? MP4 to MP3 extracts the audio track. Need to change audio formats without making a video? Use WAV to MP3 or the audio converter.
Private and free
There’s no upload, no watermark and no account. The audio and image are combined by FFmpeg compiled to WebAssembly, running inside your browser, so unreleased tracks and private recordings stay on your device.