Convert FLAC to WMA — Free Online Tool
Convert FLAC lossless audio to WMA format using the WMA v2 codec (wmav2) directly in your browser — no upload required. This is useful when you need Windows Media Player-compatible audio files from a high-quality lossless source, accepting a lossy trade-off in exchange for smaller file sizes.
to
FFmpeg Command
Copy this command to run the same conversion locally with FFmpeg on your desktop. Download FFmpeg
Drop your FLAC 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
FLAC stores audio in a lossless compressed format — every sample is preserved exactly as recorded. When converting to WMA, FFmpeg decodes the FLAC file fully back to raw PCM audio, then re-encodes it using Microsoft's WMA v2 codec (wmav2) at a target bitrate of 128k by default. This is a lossy re-encoding step: some audio information is permanently discarded to achieve compression. The output is wrapped in an ASF (Advanced Systems Format) container — the native container for WMA files — which is what Windows Media Player and many legacy Microsoft-ecosystem devices expect. Because FLAC is lossless, the WMA output will be derived from the highest-quality possible source, minimizing generational loss compared to converting from an already-lossy format like MP3.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg tool, which handles all decoding, encoding, and format conversion. In the browser version of this tool, FFmpeg runs as a WebAssembly (wasm) binary with no server involved. |
-i input.flac
|
Specifies the input file — a FLAC audio file. FFmpeg reads and fully decodes the lossless FLAC stream back to raw PCM audio before handing it to the WMA encoder. |
-c:a wmav2
|
Sets the audio codec to WMA version 2 (wmav2), Microsoft's improved WMA encoder. This produces a standard .wma file compatible with Windows Media Player and most WMA-supporting devices, and is preferred over the older wmav1 codec for better quality at equivalent bitrates. |
-b:a 128k
|
Sets the audio bitrate to 128 kilobits per second, which is the default quality level for WMA output. This determines the trade-off between file size and audio fidelity — higher values like 192k or 320k produce better-sounding WMA files at the cost of larger file sizes. |
output.wma
|
Specifies the output filename with the .wma extension, which tells FFmpeg to wrap the encoded wmav2 audio stream in an ASF container — the native container format for Windows Media Audio files. |
Common Use Cases
- Preparing audio tracks for playback on older Windows devices, car stereos, or portable media players that support WMA but not FLAC
- Reducing the file size of a large FLAC music library for storage on a Windows-centric device with limited capacity where lossless quality is not required
- Delivering audio assets to a client or platform that specifically requires WMA format, such as certain Windows-based kiosk or in-store audio systems
- Converting archival FLAC recordings to WMA for use in legacy Windows Movie Maker or older Microsoft multimedia projects
- Creating WMA files from lossless FLAC masters to distribute audio where DRM (Digital Rights Management) may later be applied via Windows Media technologies
- Generating lower-bitrate WMA versions of FLAC audiobook files for compatibility with older Audible-era Windows Media Player setups
Frequently Asked Questions
Yes — this conversion introduces lossy compression for the first time. FLAC preserves every bit of the original audio, while WMA v2 at 128k discards some audio data to reduce file size. The good news is that starting from a lossless FLAC source means you are encoding WMA from the best possible input, so there is no prior generation of lossy degradation. At 128k WMA, the result is generally considered acceptable for casual listening but is not suitable for archival or professional use.
WMA v1 (wmav1) is the original version of the codec released in 1999, while WMA v2 (wmav2) is an improved version with better audio quality at the same bitrate. This tool uses wmav2 by default, which is the standard choice for virtually all modern WMA encoding — wmav1 is only relevant for compatibility with extremely old devices or software that predate WMA v2. If you need wmav1 for a specific legacy device, you can modify the FFmpeg command manually using '-c:a wmav1'.
The size reduction depends on the original FLAC file's content and the chosen WMA bitrate. A FLAC file of a typical pop song might be around 25–40 MB, while the same song at 128k WMA would typically be 4–7 MB — roughly a 5–8x reduction. FLAC compression ratios vary by audio complexity, but WMA at a fixed bitrate produces a predictable output size: approximately 1 MB per minute of audio at 128k, or about 2.4 MB per minute at 320k.
FFmpeg attempts to map common metadata tags (such as title, artist, album, and track number) from the FLAC Vorbis comment format to ASF/WMA tag fields during conversion. Most standard tags transfer correctly. However, FLAC-specific features like embedded cue sheets and ReplayGain tags may not be fully preserved in WMA, as the ASF container has different metadata conventions and not all fields have direct equivalents.
The '-b:a 128k' flag controls the output audio bitrate. Replace '128k' with your desired value — supported options include 64k, 96k, 128k, 160k, 192k, 256k, and 320k. For example, 'ffmpeg -i input.flac -c:a wmav2 -b:a 192k output.wma' produces higher-quality WMA audio with a larger file size. Use 64k or 96k if you need the smallest possible file and can accept reduced fidelity, such as for voice recordings.
The single-file command shown on this page processes one file at a time, but you can batch convert using a shell loop. On Linux or macOS: 'for f in *.flac; do ffmpeg -i "$f" -c:a wmav2 -b:a 128k "${f%.flac}.wma"; done'. On Windows Command Prompt: 'for %f in (*.flac) do ffmpeg -i "%f" -c:a wmav2 -b:a 128k "%~nf.wma"'. This approach is especially useful if you have a large FLAC library exceeding the 1 GB browser limit for a single file.
Technical Notes
WMA files use the ASF (Advanced Systems Format) container, which is distinct from other common audio containers like MP4 or OGG. The wmav2 codec uses a transform-based lossy compression scheme similar in concept to MP3 and AAC, but optimized for Microsoft's ecosystem. One important limitation is that WMA has limited support outside of Windows: macOS and Linux can play WMA files with third-party software, but native support is absent. Mobile support is also inconsistent — Android supports WMA broadly, while iOS/iPadOS does not natively support it. FLAC supports features such as cue sheets and ReplayGain that have no equivalent in the WMA/ASF format, so these will be dropped during conversion. The ASF container does not support multiple audio tracks, subtitles, or chapters, so FLAC's metadata richness is partially truncated. Because FLAC is lossless, the WMA encoder is working from a perfect source signal, which is preferable to transcoding from a lossy format — but the wmav2 output is still irreversibly lossy and should not be used as a replacement for your original FLAC masters.