WMA to M4A

To convert WMA to M4A, pick a bitrate from the Bitrate dropdown (192k is the recommended default), then drag and drop your WMA files onto the drop area or click it to choose them — conversion to M4A starts automatically, and each finished file appears as a row with a preview player and a Download button. Set the bitrate before adding your files, because it is read at the moment each file is converted; the options are 96k, 128k, 192k, 256k and 320k. You can add several WMA files at once, and they are converted one after another entirely in your browser using a WebAssembly build of FFmpeg, so nothing is uploaded.

Because WMA is a Microsoft format that Apple never adopted, iOS has no built-in decoder for it, so the Music app simply refuses to open it. The same gap affects most Android music apps and car stereos. Converting to M4A, which is AAC audio in an MP4 container, solves it. M4A is the format iTunes and Apple Music have used for years, so a converted file drops straight into an iPhone library without any extra steps.

Yes, slightly. WMA is already a lossy format, so re-encoding it to M4A (which is also lossy) means a second round of compression, and no conversion can bring back detail the original WMA encode already discarded. At 192 kbps or higher the difference is very hard to hear on normal gear. Choose 256 or 320 kbps to keep the extra loss to a minimum. Converting to FLAC or WAV instead would stop further loss but would not improve the audio and would make the file far bigger.

Yes on both counts. It is completely free with no signup, no account, no watermark and no software to install, and it is private because the whole conversion runs inside your own browser using a WebAssembly build of FFmpeg, meaning your WMA files are never uploaded to any server. That makes it safe for confidential audio such as interviews, lectures, meeting recordings or personal voice memos, since the sound never leaves your device.

There is no size limit imposed by this site, because your files are never uploaded anywhere; the only real ceiling is how much memory your device can spare for the conversion. In practice, files over roughly a few hundred megabytes can get slow or run out of memory, especially on a phone. For long recordings such as a full album rip or an hours-long lecture, use a desktop browser, which has far more memory headroom.

192 kbps is the default and suits most WMA music and spoken-word files. AAC is generally more efficient than MP3 at the same bitrate, so 192 kbps M4A holds up well; move to 256 or 320 kbps if the source WMA was high quality and you want the least extra loss. 96 or 128 kbps gives noticeably smaller files and suits podcasts, audiobooks or voice notes. Picking a bitrate higher than the original WMA's does not improve anything, it only makes the file bigger.

Yes. The converter runs in any modern browser on Windows, Mac, Linux, iPhone and Android, because all the work is done by WebAssembly inside the browser itself, with no app to install and no operating system requirement beyond an up-to-date browser. On a phone the finished M4A saves to your downloads and can be added to your music library. For very large or very long files, a desktop browser is more reliable.