Convert M4A to MP3
M4A is what Apple records in, and MP3 is what everything else plays.
It happens on your device. Nothing is uploaded — including video.
What changes when you convert M4A to MP3
- MP3 is lossy. The quality control is a real trade, not a placebo — Smallest, Balanced and Best produce genuinely different files.
- Most browsers cannot encode MP3 on their own, so this pair usually loads a 9.7 MB engine the first time you use it — once, then cached, and the page tells you before it starts. If your browser happens to have the codec built in, it is used instead and nothing is downloaded.
How to do it
- Drop your M4A file above, or click to browse. A whole folder works too.
- MP3 is already selected. Change it on any row if you want something else.
- Pick a quality — Smallest, Balanced or Best. Balanced is a good default.
- Press Convert, then Save. Nothing left your machine.
Questions
- Is my M4A file uploaded anywhere?
- No. The conversion runs inside this browser tab using WebAssembly. There is no server involved, which is why there is no file-size cap, no queue and no account. The counter in the header measures bytes this page sends, and it stays at zero.
- Is there a file size limit?
- No imposed limit, but a real one: a browser tab has roughly 1.8 GB of working memory. Onhand estimates before it starts and tells you if a file is too large, rather than failing halfway through.
- Does it work offline?
- After one visit, yes. The page and the codecs it has used are cached, and the badge appears only when the codecs for your chosen formats are genuinely available offline — not merely because something is installed.
- Can I convert several files at once?
- Yes. Drop a folder, or select many files. Each row gets its own target format, or you can set them all at once, and everything downloads as a single zip.