Convert WMA to AAC — Free Online Converter
Convert Windows Media Audio (.wma) to Advanced Audio Coding (.aac) online for free. Fast, secure audio conversion with no watermarks or registration....
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How to Convert
Upload your .wma file by dragging it into the upload area or clicking to browse.
Choose your output settings. The default settings work great for most files.
Click Convert and download your .aac file when it's ready.
About WMA to AAC Conversion
WMA (Windows Media Audio) is Microsoft's proprietary codec that competed with MP3 throughout the 2000s, offering competitive quality in the Windows ecosystem. AAC (Advanced Audio Coding) is the industry-standard lossy codec adopted by Apple, YouTube, and every major streaming platform. AAC is technically superior to both WMA and MP3, delivering better audio quality at equivalent bitrates.
Converting WMA to AAC moves your audio from Microsoft's proprietary format to the universally adopted standard. AAC plays natively on iOS, macOS, Android, Windows, and in all modern web browsers, making it the most compatible lossy audio format available.
Why Convert WMA to AAC?
WMA's relevance has steadily declined since the end of the Zune era and Windows Phone. While Windows still supports WMA, macOS, iOS, and most mobile platforms do not play WMA natively without third-party apps. AAC, by contrast, is the native audio codec for Apple's entire ecosystem and is supported by every modern device and browser.
AAC also delivers measurably better quality than WMA Standard at equivalent bitrates. At 128 kbps, AAC produces fewer audible artifacts than WMA. Migrating a WMA library to AAC future-proofs your audio collection while improving cross-platform compatibility.
Common Use Cases
- Migrating a Windows Media Player WMA library to universal AAC format
- Converting WMA files for playback on iPhone, iPad, and Mac without third-party apps
- Preparing WMA audio for upload to platforms that prefer AAC (iTunes, YouTube, Spotify)
- Upgrading legacy WMA podcast archives to the modern AAC standard
- Converting WMA ringtones and alerts for use on non-Windows mobile devices
How It Works
FFmpeg decodes the WMA stream (wmav1/wmav2 using the ASF demuxer) to PCM, then re-encodes using the AAC encoder. The output is wrapped in an M4A container (MPEG-4 Part 14) for maximum compatibility. Since both are lossy codecs, this is a transcode with cumulative quality loss — the AAC output cannot exceed the WMA source quality. The encoder applies MDCT and psychoacoustic modeling appropriate for the target bitrate. HE-AAC and HE-AACv2 profiles are available for low-bitrate scenarios.
Quality & Performance
Transcoding from one lossy format to another always introduces some generation loss. However, if you encode the AAC at a bitrate equal to or higher than the WMA source, the additional degradation is minimal. For a 128 kbps WMA source, encoding to AAC at 192 kbps captures virtually everything the WMA preserved. At equal bitrates (128-to-128), expect subtle additional artifacts detectable only on high-end equipment.
Device Compatibility
| Device | WMA | AAC |
|---|---|---|
| Windows PC | Native | Partial |
| macOS | Partial | Native |
| iPhone/iPad | Partial | Native |
| Android | Partial | Partial |
| Linux | Partial | Partial |
| Web Browser | No | No |
Recommended Settings by Platform
Spotify
Resolution: N/A
Bitrate: 320 kbps
OGG Vorbis preferred
Apple Music
Resolution: N/A
Bitrate: 256 kbps
AAC format required
SoundCloud
Resolution: N/A
Bitrate: 128 kbps
Lossless FLAC/WAV for best quality
Podcast
Resolution: N/A
Bitrate: 128 kbps
MP3 mono for spoken word
Tips for Best Results
- 1Set the AAC bitrate 25-50% higher than the WMA source bitrate to absorb transcoding artifacts without noticeable quality loss
- 2Use AAC-LC profile for maximum device compatibility — it is the most universally supported AAC variant
- 3Preserve metadata by mapping WMA tags (ASF attributes) to MP4 atom tags during conversion
- 4Process your entire WMA library in a single batch to efficiently modernize your collection
- 5Keep the original WMA files as backup until you have verified the AAC conversions are satisfactory
Related Conversions
WMA to AAC migration modernizes your audio library for universal device compatibility. Encode at a bitrate equal to or slightly higher than the WMA source to minimize transcoding artifacts.