MP3 to MP4 (Audio + Image)
MP3 to MP4 combines an audio file with a still image, plain colour or waveform into a 720p, 1080p or square MP4 for YouTube and social sites, in your browser so nothing is uploaded.
At a glance
- Accepts
- MP3, M4A, WAV, OGG, FLAC and other audio your browser can decode, plus an optional image
- Outputs
- An H.264 MP4 with AAC audio (Opus in Firefox) at 192 kbps
- Where it runs
- Entirely in your browser, on your device
- What leaves your device
- Nothing - the file never leaves your device
- Limits
- Audio up to 4 hours on computers and 1 hour on phones (built in memory); the picture is still; needs WebCodecs
- Account
- Not required - there is no sign-up
- Price
- Free, with no watermark and no usage cap
- Made by
- Visrut
- Last updated
- 11 November 2026
YouTube and most social sites only take video, so a song, podcast or voice note needs a picture. Add your audio, pick a cover image, a plain colour or a waveform of the track, choose 720p, 1080p or square, and get an MP4 back. The picture is stored once a second, so the video part adds very little to the file size. Everything runs in your browser.
How to use it
- Choose an MP3, M4A, WAV or other audio file.
- Pick an image, a plain colour or a waveform, and the size.
- Make the MP4, play it to check, and download it.
Honest limits
- The audio is re-encoded as AAC at 192 kbps (Opus in Firefox, which has no AAC encoder), so it isn't a bit-for-bit copy of the MP3.
- The whole video is built in memory: up to 4 hours on a computer and 1 hour on a phone.
- The picture is still. The waveform shows the whole track; it doesn't move.
Frequently asked questions
Is my audio uploaded?
No. The audio is read and the video is encoded inside your browser tab. Nothing is sent to a server.
Will YouTube accept the file?
Yes. It is a standard H.264 MP4 with AAC audio, which is what YouTube recommends. Use 1080p for YouTube and Square for Instagram or Facebook feeds.
Why does a still picture video play at 1 frame per second?
Nothing moves, so more frames would only add size and encoding time. Players and YouTube handle it fine.
Does it lose audio quality?
Slightly, in theory: the audio is re-encoded at 192 kbps, which is above what YouTube streams. Nobody will hear the difference from a typical MP3.
Which browsers work?
Current Chrome, Edge and Safari 16.4 or later, and Firefox 130 or later on a computer. Firefox for Android doesn't have the video encoder yet.