ASF to WMA Converter
Convert ASF to WMA online for free. Fast, secure, and high-quality conversion with no sign-up or software required.
Maximum file size is 1GB
How it works
Three steps to your converted file
Everything happens in your browser tab - upload, pick a format, download. The heavy lifting runs on our servers.
Upload your file
Drag and drop, click to browse, or paste a URL. Batches take up to 20 files at once - 230+ input formats across video, audio, image, document, and archive types.
Choose an output format
Pick from over a hundred output formats. Filter by category or search by name - every option is open to everyone, no account needed.
Convert & download
Hit Convert and grab your download link moments later. Originals are erased when the job completes; results are cleared within about an hour.
What is an ASF file?
The Advanced Systems Format (ASF) is a proprietary digital audio and digital video container developed by Microsoft, serving as part of the Windows Media framework. It is designed for streaming media and uses a GUID-based object structure (Header, Data, and Index objects) to organize streams. ASF files typically contain Windows Media Audio (WMA) and Windows Media Video (WMV) codecs, though the container is codec-agnostic. The format supports Digital Rights Management (DRM) and extensible metadata via the Content Description Object.
How to open an ASF file
As a Microsoft-proprietary format, ASF files are natively supported on Windows operating systems via Windows Media Player and the Movies & TV app. macOS users generally cannot open ASF files without third-party components like Flip4Mac (discontinued) or universal players. The most reliable cross-platform solution for playing ASF containers without codec errors is the VLC media player, which supports the underlying WMA and WMV streams independently of the OS framework.
ASF Technical Info
- Full Name
- Advanced Systems Format
- Developed By
- Microsoft
- Initial Release
- 1996
- MIME Type
- video/x-ms-asf
What is a WMA file?
Windows Media Audio (WMA) refers to a series of audio codecs and their corresponding Microsoft container format, designed as a competitor to MP3 and RealAudio. The standard WMA codec is lossy, but the format family includes WMA Lossless, WMA Pro (multichannel), and WMA Voice. It utilizes the Advanced Systems Format (ASF) container structure and supports digital rights management (DRM), which historically restricted playback to authorized Windows devices.
How to open a WMA file
WMA files are native to the Windows ecosystem and open by default in Windows Media Player and Movies & TV. macOS users require third-party components like Flip4Mac (legacy) or universal players such as VLC Media Player and Elmedia Player to decode the stream. Android and Linux support is generally provided via VLC or by installing ffmpeg-based media libraries.
WMA Technical Info
- Full Name
- Windows Media Audio
- Developed By
- Microsoft
- Initial Release
- 1999
- MIME Type
- audio/x-ms-wma
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Purpose-built for speed, privacy, and breadth of format support.
Convert ASF to WMA in seconds
Every ASF to WMA conversion runs on our servers, so your device stays fast and the output quality stays intact.
Fast, cloud-powered
No queue, no waiting. Files are processed on high-performance servers and returned in seconds, even for large files.
Secure & private
Encrypted in transit and never shared with anyone. Uploads are erased the moment your job completes, and results shortly after.
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Developer API
Convert ASF to WMA via API
Automate ASF to WMA conversions in three steps: create a job, upload your file, then poll for the result.
# 1. Create job
curl -X POST https://api.runconvert.com/v3/jobs \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"tag": "asf-to-wma",
"tasks": {
"upload-file": {
"operation": "import/upload"
},
"convert": {
"operation": "convert",
"input": "upload-file",
"output_format": "wma"
},
"export-result": {
"operation": "export/url",
"input": "convert"
}
}
}'
# 2. Upload your file (use upload_url from the response)
curl -X PUT "$UPLOAD_URL" --upload-file input.asf
# 3. Poll for result
curl https://api.runconvert.com/v3/jobs/$JOB_ID?include=tasks \
-H "Authorization: Bearer YOUR_API_KEY"Replace YOUR_API_KEY with your RunConvert API key. Get your free API key at runconvert.com/api.