Convert WMA to FLAC — Free Online Tool
Convert WMA files to FLAC, preserving every bit of audio data in a lossless open-source format. Since WMA uses lossy compression (wmav2/wmav1 codecs), the FLAC output will be a lossless capture of the decoded audio — ideal for archiving or reprocessing your WMA library without introducing additional generation loss.
to
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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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
During conversion, FFmpeg decodes the WMA audio stream (encoded with Microsoft's proprietary wmav2 or wmav1 codec) into raw PCM audio, then re-encodes it using the FLAC codec with lossless compression. Because WMA is a lossy format, the FLAC output captures the fully decoded audio exactly — no further quality is lost in this conversion, but the audio fidelity is bounded by whatever was lost when the original WMA was created. The resulting FLAC file is significantly larger than the WMA source because lossless compression does not discard audio data the way lossy codecs do.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg tool, the open-source multimedia processing engine that handles decoding the proprietary WMA audio stream and re-encoding it to FLAC. |
-i input.wma
|
Specifies the input file — a WMA audio file using Microsoft's ASF container, typically encoded with the wmav2 or wmav1 lossy audio codec. |
-c:a flac
|
Sets the audio codec for the output to FLAC, instructing FFmpeg to encode the decoded WMA audio into the lossless FLAC format instead of copying or using any other codec. |
-compression_level 5
|
Sets the FLAC encoder's compression effort to level 5 (out of 0–8). This controls encode speed and output file size only — audio quality is identical at all levels since FLAC is always lossless. Level 5 is the standard default offering a good balance between speed and file size. |
output.flac
|
The destination filename with a .flac extension, telling FFmpeg to write the result into a FLAC container holding the losslessly encoded audio decoded from the original WMA source. |
Common Use Cases
- Archiving an old WMA music library into an open, future-proof format that any media player or OS can read without Microsoft codec dependencies
- Preparing WMA tracks for re-editing or mixing in a DAW, where lossless source files prevent additional quality degradation from re-encoding
- Migrating a Windows Media Player collection to a FLAC-based music server like Jellyfin or Navidrome that natively indexes lossless files
- Stripping DRM-free WMA files from a legacy device backup and converting them to FLAC for long-term storage on a NAS
- Converting WMA audiobook files to FLAC so they can be imported into archival or transcription workflows that require uncompressed-equivalent audio fidelity
- Producing a lossless master from a WMA broadcast recording before further processing such as noise reduction or normalization
Frequently Asked Questions
No. WMA is a lossy format, meaning audio data was permanently discarded when the WMA file was originally encoded. Converting to FLAC captures the decoded output of that lossy file without losing anything further, but it cannot restore information that was already thrown away. The result is a lossless snapshot of whatever quality the WMA contained — useful for preventing any additional generation loss, but not a quality upgrade.
WMA achieves small file sizes by discarding audio data through lossy compression (typically at 128 kbps by default). FLAC, on the other hand, uses lossless compression that retains every sample of the decoded audio, which inherently requires more space. A 128 kbps WMA file might expand to 5–10× its original size as a FLAC, even though no new audio quality has been added — you're simply storing the decoded audio efficiently rather than compressively.
FFmpeg will attempt to carry over standard metadata tags (artist, album, title, track number, etc.) from the WMA container to the FLAC container during conversion. Both formats support metadata tagging, so common fields typically transfer correctly. However, WMA uses ASF/WMA-specific tag fields internally, and any non-standard or proprietary Microsoft-specific metadata may not map cleanly to FLAC's Vorbis comment tag structure.
The -compression_level flag controls how hard the FLAC encoder works to shrink the file, on a scale from 0 (fastest, largest files) to 8 (slowest, smallest files). Critically, this affects only encode speed and file size — the audio quality is identical at every compression level because FLAC is always lossless. Level 5 is the widely accepted default that balances speed and file size well. You might lower it to 0 or 1 for faster encoding of large batches, or raise it to 8 if storage space is the top priority.
The single command shown processes one file at a time. To batch convert an entire folder on Linux or macOS, you can use a shell loop: `for f in *.wma; do ffmpeg -i "$f" -c:a flac -compression_level 5 "${f%.wma}.flac"; done`. On Windows Command Prompt, use `for %f in (*.wma) do ffmpeg -i "%f" -c:a flac -compression_level 5 "%~nf.flac"`. The browser-based tool processes one file per conversion.
No. DRM-protected WMA files use Microsoft's PlayReady or earlier Windows Media DRM encryption, which prevents FFmpeg (and this browser tool) from decoding the audio stream. Only DRM-free WMA files can be converted. If your WMA files were purchased from a store that applied DRM, you will need to check whether the provider offers a DRM-free download option before converting.
Technical Notes
WMA files use Microsoft's proprietary ASF (Advanced Systems Format) container with either the wmav2 (more common, better quality) or wmav1 (older, rarer) audio codec. Both are lossy codecs that operate on psychoacoustic principles similar to MP3, meaning they permanently remove audio frequencies deemed less perceptible to human hearing. FLAC, by contrast, uses linear prediction and Rice coding to compress audio without any data loss, and its specification is fully open and royalty-free. Because the conversion path is lossy-to-lossless (decode WMA → encode FLAC), there is no transcoding quality penalty beyond what the original WMA encoding already imposed. Metadata compatibility is generally good for standard Vorbis comment fields in FLAC, but WMA's ASF container can carry proprietary Microsoft tags and DRM licensing metadata that will not transfer. FLAC does not support DRM, multiple audio tracks, or subtitle streams — none of which are relevant here since WMA is also a single-stream audio-only format. The output FLAC file will be natively playable on virtually all modern operating systems, media players, and streaming servers without requiring any Microsoft codec installations.