WMA to M4A Converter

How to Convert WMA to M4A Online

1. Upload Your WMA File: Drag and drop or click "+ Add Files" to select WMA tracks from your computer. Batch upload is supported, so an entire Windows Media Player library can be queued in one pass.
2. Set the Bitrate under File Compression: File Compression opens on Quality Preset, but nothing is pre-selected in that dropdown — it displays "Highest" as a placeholder — and it is the least predictable control on the page. Switch to Constant Bitrate instead, which maps one-to-one onto the encoder: the dropdown opens at 128 kbps and the list runs up to 384 kbps, with 256 kbps matching what Apple Music uses for standard streaming, 192 kbps ample for podcasts and audiobooks, and 128 kbps the option that shrinks storage. Variable Bitrate offers five AAC bands (96k-112k down to 20k-32k), and Custom Bitrate takes an exact typed value in bps, Kbps or Mbps.
3. Set Channels, Sample Rate, or Trim (Optional): Switch Audio Channel between Mono and Stereo, force Audio Sample Rate to 44100 Hz (CD), 48000 Hz (broadcast), or leave it at the source rate. Use Trim with the HH:MM:SS.mmm input to clip silence, intros, or DRM-free preview segments before encoding.
4. Convert and Download: Click Convert. Files are uploaded over an encrypted connection, processed on our servers, and deleted automatically after a few hours — no sign-up, no watermark, never shared.

Why Convert WMA to M4A?

Windows Media Audio is a Microsoft-only container that Apple devices have never natively supported. iTunes, Apple Music, the Music app on iOS/macOS, HomePod, CarPlay, and the Apple Watch all reject .wma outright; ripping a WMA library to M4A (AAC) is the only path to play it in the Apple ecosystem. Microsoft itself moved away from the codec — its own Zune Marketplace switched from WMA-only to MP3 in 2011, and Windows Media Encoder is no longer maintained on Windows 10/11 after required components were removed in 2017. M4A is the modern alternative: an MP4 container (ISO/IEC 14496-14) carrying AAC-LC or Apple Lossless (ALAC), royalty-free since Apple open-sourced ALAC in late 2011.

• Migrating to Apple Music or iPhone — WMA imported into iTunes on Windows used to auto-transcode to AAC, but the Apple Music app on macOS and the iOS Files app refuse .wma entirely. Convert before sync to avoid silent skips in playlists.
• CarPlay, HomePod, and Apple Watch playback — None of these devices ship a WMA decoder. M4A/AAC is the native sideload format and works without re-encoding.
• Reducing library size without re-ripping CDs — At 192 kbps, AAC in M4A is generally considered transparent to most listeners and roughly 15–20% smaller than an equivalent-quality MP3 — useful when shrinking a 50 GB WMA archive to fit on a 32 GB iPhone.
• Preserving lossless WMA quality — If the source is WMA Lossless (the WMA 9 Lossless variant), encode to ALAC inside M4A to keep bit-perfect quality. AAC is lossy, so picking it on a lossless source discards data permanently.
• Audiobooks and podcasts — M4A is the audiobook-grade container; renaming to .m4b adds chapter and bookmark support in the Apple Books app, which WMA never supported.
• Cross-platform reach — Beyond Apple, M4A plays in VLC, foobar2000, Plex, Android (since 3.0 Honeycomb), and most factory car stereos shipped since ~2014, where WMA support has been dropped from new head units.

WMA vs M4A — Format Comparison

M4A Codec & Bitrate Quick Guide

Frequently Asked Questions

Why won't my WMA files play in iTunes or Apple Music on macOS?

Apple removed WMA decoding from the Mac version of iTunes years ago, and the modern Music app on macOS Catalina and later does not ship a WMA codec at all. On Windows, older iTunes versions could auto-transcode unprotected WMA to AAC at import, but that path is fragile and fails on DRM-protected files. Converting to M4A (AAC) up front is the only reliable way to get a WMA library into the Apple Music app, iCloud Music Library, or onto an iPhone, iPad, Apple Watch, or HomePod.

Will I lose quality converting WMA to M4A?

Slightly, because both standard WMA and AAC are lossy codecs — re-encoding any lossy source loses a small amount of detail. In blind listening tests this is generally inaudible when you encode to AAC at 256 kbps (Constant Bitrate 256 kbps) from a 128-192 kbps WMA source. If the input is WMA Lossless (the WMA 9 Lossless variant, often >800 kbps), pick ALAC instead of AAC to preserve every bit.

Should I pick AAC or ALAC for the M4A output?

Pick AAC-LC for normal music libraries — it is what iTunes Store purchases, Apple Music streams, and most third-party stores use. Files are ~10x smaller than ALAC at perceptually transparent quality. Pick ALAC only when (a) your source is WMA Lossless or another lossless format and (b) you have the storage and care about archival quality — for example, when transcoding a CD-quality WMA Lossless rip for an Apple Music library marked Lossless.

What bitrate matches the original WMA file?

Roughly, AAC reaches the same perceived quality at about 70-80% of the WMA bitrate — a 128 kbps WMA file generally sounds equivalent at ~96-112 kbps AAC. To be safe, encode one tier higher: 128 kbps WMA → 128 kbps AAC, or 192 kbps WMA → 192 kbps AAC. Nothing here matches the source rate for you — pick the figure yourself under Constant Bitrate, which is the mode that maps one-to-one onto the encoder and gives you the rate you asked for.

Will tags, album art, and track numbers transfer?

Yes — xConvert maps WMA's ASF metadata (title, artist, album, year, track, genre, embedded album art) into M4A's iTunes-compatible MP4 atoms during conversion. Custom WMA-only fields like "Mood" or "Sub-Genre" that have no MP4 equivalent are dropped, but everything iTunes, Apple Music, and the iPhone Music app display will carry over.

Can I convert DRM-protected WMA files?

No. Files encoded with Windows Media DRM (the old PlaysForSure scheme, Zune Marketplace downloads, or rented Napster/Yahoo Music tracks) cannot be re-encoded by any converter — that is what DRM enforces. The track has to be playable on the original licensed Windows PC and re-recorded through the analog or loopback path, which is outside what this tool does. Unprotected ripped CDs and self-encoded WMA files convert normally.

Should I use M4A or MP3 for my Apple library?

M4A. The Apple Music app, iTunes Store, and every Apple device since the iPod nano (2nd gen, 2006) treat M4A/AAC as the first-class format — it gives smaller files at the same perceived quality as MP3 and supports gapless playback metadata, chapter markers, and lossless (ALAC). MP3 is more universal across non-Apple hardware, but if the goal is Apple compatibility, M4A is the better choice. If you need MP3 anyway, convert WMA to MP3 instead.

Can I convert M4A back to WMA later?

Yes, though there's rarely a reason to. WMA's main remaining use case is older Windows Mobile / Pocket PC devices and some 2005-2012 car stereos; everything modern plays M4A. If you specifically need it, the reverse direction is supported too — and you can also convert WMA to AAC (raw AAC stream, no MP4 container) or convert WMA to MP3 for legacy hardware.

Why is my output file larger than the source WMA?

Usually because the bitrate you set under File Compression is higher than the source WMA's — the Constant Bitrate dropdown opens at 128 kbps, and plenty of WMA files sit at 64-96 kbps — or because you selected ALAC on a lossy source, which inflates a lossy input back toward CD-rate sizes without restoring lost quality. Lower the Constant Bitrate to match the source, or pick AAC to keep file sizes in line. The Quality Preset dropdown is not the place to fix this: it pre-selects nothing and is the least predictable control on the page. If you need to shrink finished M4As further, see compress M4A.