Convert WMA to AIFF — Free Online Tool
Convert WMA files to AIFF by decoding Microsoft's lossy wmav2 audio stream into uncompressed PCM audio stored in Apple's lossless AIFF container. Ideal for bringing Windows Media Audio into professional macOS audio workflows where uncompressed fidelity is required.
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FFmpeg Command
Copy this command to run the same conversion locally with FFmpeg on your desktop. Download FFmpeg
Drop your WMA file here
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Free — no uploads, no signups. Your files never leave your browser.
Settings
Note: Browser-based encoding uses approximate quality targets. For precise CRF compression, copy the FFmpeg command above and run it on your desktop.
Estimated output:
Conversion Complete!
DownloadHow It Works
WMA files encode audio using Microsoft's wmav2 (or wmav1) lossy codec, which discards audio data during compression — similar in principle to MP3. During conversion, FFmpeg fully decodes the WMA stream back to raw PCM audio samples, then re-encodes those samples as 16-bit big-endian PCM (pcm_s16be) and packages them into an AIFF container. Because WMA is lossy, the original audio data that was discarded during WMA encoding cannot be recovered — the AIFF output will be lossless and uncompressed, but its quality ceiling is bounded by the quality of the source WMA file. Think of it as freezing the lossy WMA audio in an uncompressed state: no further generation loss will occur from this point forward, but the conversion cannot undo prior lossy compression.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg binary. In the browser-based version of this tool, this runs via FFmpeg.wasm compiled to WebAssembly — no installation required and no files leave your device. |
-i input.wma
|
Specifies the input WMA file. FFmpeg detects the WMA container and identifies the audio stream as wmav2 (or wmav1), which it will fully decode before re-encoding into PCM for the AIFF output. |
-c:a pcm_s16be
|
Sets the audio codec for the output to 16-bit signed big-endian PCM — the native, uncompressed audio format inside an AIFF container. This produces CD-quality uncompressed audio compatible with all AIFF-reading applications on macOS and elsewhere. |
output.aiff
|
Defines the output filename and tells FFmpeg to write an AIFF container. The .aiff extension causes FFmpeg to use the AIFF muxer, which wraps the pcm_s16be audio stream in Apple's big-endian uncompressed audio format. |
Common Use Cases
- Importing Windows Media Audio files into Logic Pro, GarageBand, or Pro Tools on macOS, which natively read AIFF but often struggle with WMA
- Archiving a legacy WMA music or audiobook collection in an uncompressed format to prevent further quality degradation from re-encoding in the future
- Preparing WMA audio assets for use in Final Cut Pro timelines, where AIFF/PCM tracks integrate without transcoding delays
- Delivering audio to a mastering engineer or studio that requires uncompressed source files rather than proprietary compressed formats
- Converting WMA podcast recordings or interview files to AIFF before editing in a DAW that does not support the WMA codec
- Moving audio files from a Windows-centric workflow to a macOS post-production pipeline where AIFF is the standard interchange format
Frequently Asked Questions
No — converting from WMA to AIFF does not recover audio quality lost during the original WMA encoding. WMA uses lossy compression that permanently discards audio data, and decoding it to uncompressed PCM simply preserves whatever quality remains in the WMA file. The AIFF will be bit-for-bit stable and will not degrade further if re-processed, but it cannot sound better than its lossy source.
WMA is a lossy compressed format, so it stores audio in a highly compact form — a typical 128 kbps WMA file might be around 1 MB per minute. AIFF with pcm_s16be stores every audio sample uncompressed at CD quality (16-bit, big-endian), which requires roughly 10 MB per minute for stereo audio at 44.1 kHz. The large size difference reflects the removal of WMA's compression, not any addition of audio data.
WMA files commonly store metadata using Windows Media attributes, and AIFF supports a limited set of metadata via its MARK and NAME chunks, as well as ID3 tags in newer implementations. FFmpeg will attempt to map standard tags (title, artist, album) during conversion, but some WMA-specific or DRM-related metadata fields may not transfer cleanly. It is worth verifying tags in your target application after conversion.
Yes — AIFF supports higher bit depths including 24-bit (pcm_s24be) and 32-bit (pcm_s32be) PCM. You can modify the FFmpeg command to use a higher-depth codec, for example replacing '-c:a pcm_s16be' with '-c:a pcm_s24be'. However, since WMA is a lossy format typically mastered at 16-bit equivalent quality or lower, using 24-bit output increases file size without recovering additional audio detail from the source.
FFmpeg cannot decode DRM-protected WMA files. Microsoft's DRM (Digital Rights Management) encryption prevents the audio stream from being decoded without the appropriate license, so FFmpeg will return an error rather than produce an output file. Only DRM-free WMA files can be converted using this tool or the FFmpeg command provided.
On macOS or Linux, you can use a shell loop: 'for f in *.wma; do ffmpeg -i "$f" -c:a pcm_s16be "${f%.wma}.aiff"; done'. On Windows Command Prompt, use: 'for %f in (*.wma) do ffmpeg -i "%f" -c:a pcm_s16be "%~nf.aiff"'. Each WMA file in the directory will be decoded and saved as a separate AIFF file with the same base filename.
Technical Notes
The conversion pipeline decodes wmav2 (the default and most common WMA codec, used since Windows Media Player 7) or the older wmav1 variant, both of which are psychoacoustic lossy codecs developed by Microsoft as alternatives to MP3. The decoded PCM is written into AIFF using the pcm_s16be codec — 16-bit signed integer samples stored in big-endian byte order, which is AIFF's native and most broadly compatible format. AIFF is a big-endian format developed by Apple in 1988, and pcm_s16be maps directly onto CD-quality audio (16-bit / 44.1 kHz or 48 kHz stereo). The output sample rate and channel count are inherited from the source WMA file unless explicitly overridden with '-ar' and '-ac' flags. WMA's support for DRM means that commercially purchased or rights-protected WMA files will fail to decode — only DRM-free WMA files are processable. The WMA container does not support subtitles, chapters, or multiple audio tracks, so none of those considerations apply to this conversion. Files encoded at lower WMA bitrates (64 kbps or 96 kbps) will exhibit audible lossy compression artifacts that become more apparent in the uncompressed AIFF output when listened to carefully on high-quality monitoring equipment.