MP3 to MP4 Converter
Wrap audio in an MP4 with album art or waveform. Ready for YouTube. Stays in your browser.
Best for uploading podcast episodes, music tracks, or audiobooks to YouTube or platforms that only accept video files.
Drop files here
or click to browse · paste from clipboard
Accepts .MP3, .WAV, .OGG, .FLAC, .AAC · Up to 1,000 files
How it works
Drop your files
Drag and drop, click to browse, or paste from clipboard. Up to 1,000 files at once.
Choose settings
Adjust quality, format, and other options to match your needs.
Click Convert
Everything runs in your browser via WebAssembly. MP3 to MP4 Converter happens locally — no server involved.
Download
Download files individually or grab all at once as a ZIP.
Frequently asked questions
Many platforms — YouTube, Instagram, TikTok, Facebook — require a video file for uploads. An MP4 with a static image and your audio track satisfies their requirements without any visible change to the listening experience. It's the standard approach for uploading podcast episodes, music tracks, and audiobooks to video platforms.
Your choice: a solid black screen (default, smallest file), a custom color, or a static JPG/PNG image you upload — like album art or a thumbnail. You can also add an animated white waveform over any of these backgrounds. For music and podcasts on YouTube, a static image with no waveform is the most common approach.
Static-background MP4s are very small. A 1-hour MP3 with a black background at 720p is typically 80–100 MB. The audio track (AAC at 192 kbps) makes up almost all of the file size — the static video track compresses to almost nothing with libx264. Waveform animations will produce larger files since the video content changes every frame.
The audio is re-encoded from MP3 to AAC at 192 kbps. AAC at 192 kbps is perceptually transparent — most listeners cannot distinguish it from the MP3 original on normal speakers or headphones. If your source is already high quality (256+ kbps MP3), the output will sound indistinguishable.
Never. Conversion runs entirely in your browser using ffmpeg.wasm — a full port of FFmpeg compiled to WebAssembly. Your audio and image files never leave your device. ConvertYard's servers only deliver the page's code and the ~25 MB WASM engine on first load.
Yes. Drop as many files as you need. Each one is converted in sequence using the same background and waveform settings, and all outputs are bundled into a single ZIP for download. There is no hard file count limit.
Set Background to "Upload image," then pick your JPG or PNG. The image is scaled to fill the selected resolution (720p or 1080p). Use a square image for music (standard album art) or a 16:9 image for YouTube thumbnails — the converter will scale and letterbox if dimensions don't match exactly.
Bar waveform (mode=p2p) shows amplitude peaks as bars — a clean, energetic look common in music visualizers. Line waveform draws the raw audio waveform as a continuous line — subtler, better for spoken word or podcasts. Both are animated in sync with the audio. For most YouTube uploads, a static background with no waveform loads faster and looks just as professional.