Convert MP3 to MP4 with an image, free and private
Most video sites and messaging apps will not take a plain sound file. This tool turns MP3 to MP4 with an image: pick the audio — a song, a podcast episode, a lecture, a voice note — add a picture such as the cover art or a photo, and download an MP4 video that YouTube, WhatsApp, Instagram, Facebook and X accept. Add several pictures and they become a slideshow that runs through the audio.
Everything is done in your browser with the built-in video encoder, so long recordings and unreleased music never leave your computer. A still picture needs very few frames — at one frame per second an hour of audio is only 3,600 frames — so even long files are fast and small.
How to use the Audio to Video (MP3 to MP4 with Image)
- Drop the audio file in box 1, then one or more pictures in box 2 (or press Try a generated example).
- Reorder or remove pictures with the arrows and ✕ in the list.
- Choose the format: 16:9 for YouTube, 1:1 for feeds, 9:16 for Reels, Shorts and WhatsApp Status, and 1080p or 720p.
- Choose how the picture fills the frame: crop to fill, fit with a blurred copy behind, or fit on a colour. Drag the preview slider to check.
- For a slideshow, spread the pictures over the audio or give each a fixed time; pick 30 fps for crossfades.
- Press Create MP4. The video downloads when it is ready and plays below.
Audio to Video (MP3 to MP4 with Image) features
Any audio in
MP3, M4A/AAC, WAV, FLAC, Ogg, Opus, or the sound of a video file — up to 4 hours.
Three sizes
1920 × 1080 or 1280 × 720 landscape, 1080 × 1080 square, 1080 × 1920 vertical.
Fill or fit
Crop to fill the frame, or keep the whole picture with a blurred background or plain colour bars.
Slideshows
Up to 50 pictures, in your order, spread evenly or a fixed number of seconds each, with optional crossfades.
Small, standard files
H.264 video and AAC sound in an MP4; at 1 fps the picture adds very little to the file size.
No watermark, no upload
The video is made on your device and is yours to use.
Which format for which site?
| Where it goes | Format | Notes |
|---|---|---|
| YouTube, Vimeo, a website | 16:9 · 1080p | Use the cover art or a photo; 1 fps is fine for a still picture |
| Instagram or Facebook feed, LinkedIn | 1:1 · 1080p | Square shows largest in a scrolling feed |
| Reels, Shorts, TikTok, WhatsApp Status | 9:16 · 1080p | “Fit, blurred copy behind” keeps a square cover readable |
| WhatsApp chat or email | 16:9 or 1:1 · 720p | Smaller file; WhatsApp limits video size and length |
How it works
The audio is decoded and passed straight to an AAC encoder (128 kbit/s mono or 192 kbit/s stereo) at its own sample rate. Each picture is scaled once for the frame size you chose, and the frames are encoded to H.264 with WebCodecs. The open-source Mediabunny library (MPL-2.0) writes both into an MP4 with the index at the start, so the video starts playing before it has fully downloaded.
A static picture changes nothing between frames, so one frame per second is enough and keeps the file small; every second frame is a keyframe so players can jump anywhere. Choose 30 fps only for crossfades or if an editing program needs a standard frame rate.
Related tools
For a moving spectrum or waveform instead of a still picture, use the Audio Visualizer. For a captioned highlight from a podcast, use the Podcast Clip Maker. To put new sound on an existing video, use Add Audio to Video.
Audio to Video (MP3 to MP4 with Image) FAQ
How do I convert MP3 to MP4 with an image for free?
Drop the MP3, drop a picture, choose 16:9 and press Create MP4. There is no sign-up, no watermark and no upload.
Can I use several pictures?
Yes. Drop several images; they play in the order of the list, spread evenly over the audio or for a fixed time each. Choose 30 fps for crossfades.
Will the sound quality drop?
The sound is encoded once to AAC at 192 kbit/s for stereo (128 kbit/s mono), which is transparent for most listeners and what YouTube uses itself.
Why is the video so small?
A still picture does not change, so the tool uses one frame per second. The size is mostly the audio.
Can I make a video for WhatsApp Status?
Yes — choose 9:16. WhatsApp shows up to 60 seconds per status, so cut longer audio first with the Audio Cutter.
Does it work on a phone?
Yes in current Chrome and Safari, but long or 1080p videos take longer on a phone; 720p is quicker.