FLV to ASF Converter
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Supports: FLV
Advanced Options - Our defaults are optimized for the best results. We recommend you keeping the defaults unless you have a specific need.
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Need help?How to Convert FLV to ASF Online
- Upload Your FLV Files — Drag and drop or select one or more FLV (Flash Video) files.
- Choose a Quality Preset — Select from Highest, Very High (Recommended), High, Medium, Low, Very Low, or Lowest.
- Adjust Resolution (Optional) — Keep original, pick a preset (4320p down to 144p), or enter exact width and/or height in pixels or percent.
- Trim (Optional) — Set a start time and duration in seconds or HH:MM:SS.sss to extract a specific segment.
- Convert & Download — Click Convert and download your ASF files.
The video codec defaults to WMV2 and the audio codec defaults to WMA v2 for ASF output. Both can be changed under Advanced settings.
Why Convert FLV to ASF?
FLV (Flash Video) was the web's dominant video format until Adobe discontinued Flash Player in 2020. ASF (Advanced Systems Format) is Microsoft's streaming media container, designed for Windows Media Player and Windows-based streaming servers. Converting FLV to ASF gives you a format that plays natively on every Windows PC without additional codecs, integrates with Windows Media Services for streaming, and supports DRM for content protection.
FLV vs ASF
| Feature | FLV (Flash Video) | ASF (Advanced Systems Format) |
|---|---|---|
| Developer | Adobe (discontinued) | Microsoft |
| Era | 2003–2020 | 1996–present |
| Windows native playback | ❌ (requires codec) | ✅ (Windows Media Player) |
| Streaming support | Flash-based (dead) | ✅ (Windows Media Services) |
| DRM support | ❌ | ✅ |
| Default video codec | H.264 / VP6 | WMV |
| Default audio codec | MP3 / AAC | WMA |
Use Cases
- Windows playback — Convert old FLV files to ASF for native playback in Windows Media Player without installing additional codecs.
- Windows streaming — ASF is the native format for Windows Media Services and IIS Media Services streaming.
- Legacy Flash content — Preserve Flash-era video content in a format that remains supported on Windows.
- Corporate environments — Many enterprise Windows deployments support ASF/WMV natively but block third-party codec installations.
What is ASF?
ASF (Advanced Systems Format) is Microsoft's container format for streaming media. It can hold WMV video, WMA audio, metadata, and scripts. ASF is the basis for both .wmv (video) and .wma (audio) file extensions.
Will ASF play on Mac or Linux?
ASF is primarily a Windows format. VLC plays ASF on all platforms. macOS and Linux do not have native ASF support without third-party players.
What video codec does the ASF output use?
WMV2 (Windows Media Video 2) by default. You can switch to WMV1, H.264, VP8, or other codecs under Video Codec in Advanced settings.
Can I trim the video during conversion?
Yes. Use the Trim option to set a start time and duration in seconds or HH:MM:SS.sss.
Is Flash still needed to play FLV files?
No. Adobe Flash Player was discontinued in December 2020. FLV files can still be played with VLC or converted to modern formats like ASF, MP4, or MKV.