MP3 to MP4: add a picture to audio
Turn an MP3 or other audio file and a picture into an MP4 video you can post on YouTube, Instagram or TikTok. No picture? Use a plain colour.
- 100% free
- Runs in your browser
- No uploads
- Runs on your deviceEvery tool works directly in your browser. No files are uploaded.
- Your privacy mattersYour files never leave your device, so there's nothing for us to store.
- No limitsUse any tool as much as you need. No daily caps, no waiting.
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How to convert MP3 to MP4
- Add the audio. Drop an MP3, M4A, WAV, OGG or FLAC file.
- Add a picture. Cover art, a photo or a logo in JPG, PNG or WebP. Skip it for a plain colour.
- Pick the size. 16:9 for YouTube, 1:1 for posts, 9:16 for Reels, Shorts and TikTok. The preview shows the frame.
- Make the video and download it. Play it on the page first to check the sound and picture.
Which size to choose
| Size | Pixels | Use it for |
|---|---|---|
| 16:9, 1080p | 1920 × 1080 | YouTube, Facebook, sharing to computers and TVs |
| 16:9, 720p | 1280 × 720 | The same, made faster and a little smaller |
| 1:1 square | 1080 × 1080 | Instagram and Facebook feed posts; album covers fit exactly |
| 9:16 vertical | 1080 × 1920 | Reels, YouTube Shorts, TikTok, Stories |
How it works
The picture is drawn once at the size you chose: whole, with a blurred copy of itself or a colour around it, or filling the frame with the edges cropped. That frame is then repeated for the length of the audio and encoded as H.264. A picture that never changes compresses very well, so most of the file is the sound, and the video is usually not much larger than the audio file.
The sound is copied as it is when it's already AAC (most M4A files); otherwise it's encoded to AAC at 192 kbps. Browsers that can't make MP4 save a WebM file instead.
Tips
- Square cover art on YouTube: keep "Show it whole" with the blurred background rather than cropping the art.
- Use a large picture, at least as big as the video (1920 pixels wide for 1080p), so it stays sharp.
- Too long for a Short or Reel? Cut the part you want with Trim audio first.
Frequently asked questions
Why convert MP3 to MP4 at all?
YouTube, Instagram, TikTok and Facebook take videos, not sound files. Putting your audio over a still picture, such as cover art or a photo, makes a video they accept, so you can share a song, a podcast episode or a recording.
Is the sound quality reduced?
M4A files with AAC sound are copied into the video untouched. MP3, WAV, OGG and FLAC are converted to AAC at 192 kbps, which is the format MP4 players expect and sounds the same as a good MP3 to most listeners.
Will YouTube and Instagram accept the video?
Yes. The video is H.264 with AAC sound in an MP4 file, the format both recommend. Pick 16:9 for YouTube, 1:1 for Instagram posts and 9:16 for Reels, Shorts and TikTok. Each site has its own length limits, so check those for long recordings.
How long can the audio be?
Up to 6 hours. Long files take longer to make, because the picture is written as a frame many times a second. For a long podcast, choose 1 fps: it's much faster and YouTube plays it the same, since the picture doesn't move.
Are my files uploaded?
No. The audio and picture are combined inside this browser tab, and the video is saved straight to your device.
Can I add a moving waveform or lyrics?
Not here: the video shows one still picture for the whole length. If you need to cut the audio first, use Trim audio, then come back.