Step 1: Provide your WMV files using the button above or by toss and let go.
Step 2: Click the 'Convert' button to start the conversion.
Step 3: Fetch your converted FLV files.
WMV to FLV Conversion FAQ
How do I convert WMV to FLV without re-encoding the video stream?
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There is no stream-copy switch on this page. A few pairs copy a compatible video stream into the FLV container without re-encoding it, MKV to MP4 among them, which is quick and loses no quality. Most pairs re-encode the video. WMV carries Microsoft’s own VC-1 or WMV3 video with WMA audio — codecs almost nothing outside Windows decodes natively. FLV typically holds Sorenson Spark or H.264 video with MP3 or AAC audio, wrapped in a stream format designed for RTMP delivery.
My WMV footage shows comb lines on movement — will that carry into the FLV?
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Yes. WMV content is often interlaced, because the format comes from the broadcast and DVD era, and this converter has no deinterlace option, so the combing carries into the FLV. If it matters, deinterlace the WMV first in a desktop tool such as HandBrake or ffmpeg (the yadif filter). WMV is Windows Media Video, Microsoft’s ASF-based format from the Windows XP era.
Why does my WMV file fail to convert to FLV?
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Almost always DRM. Some WMV files are encrypted at the bitstream level by the store or software that issued them, and an encrypted stream cannot be decoded by us or by anything else without the licence key. Files you recorded, exported or downloaded unprotected convert normally; a licensed purchase will not, and no converter can honestly promise otherwise. WMV is effectively a dead end: macOS, iOS, Android and every browser need third-party decoders, and some WMV files carry DRM that cannot be converted at all.
Is there any point converting between two legacy formats like WMV and FLV?
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Only if a specific piece of equipment demands the target. Both formats come from the same pre-H.264 era, so neither conversion buys efficiency, quality or future-proofing — it buys compatibility with one particular device. If the goal is to keep the footage usable long-term, convert to a current container instead of sideways. No current browser, phone or TV can play FLV — anything still in this container has to be moved out of it to remain watchable.
Will multi-track audio survive WMV to FLV conversion?
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Usually not. Most conversions keep one audio track, the one with the most channels (normally the main mix), re-encoded for the FLV container, so commentary and alternate-language tracks are dropped. AVI, WMV, MPEG, FLV, VOB and M4V to MKV keep every track, and so does MP4 to MOV. To keep a different track, remux the WMV with that track first (VLC or ffmpeg can do this), then convert it. FLV is the Flash Video container that carried essentially all web video from roughly 2003 until Flash was switched off at the end of 2020.
Are subtitle tracks preserved when converting WMV to FLV?
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On some pairs. MP4 to MOV keeps every text subtitle track. AVI, WMV, MPEG, FLV, VOB and M4V to MKV keep every subtitle track: text subtitles are copied or converted to SRT, and picture-based subtitles such as DVD or Blu-ray ones are copied as they are. MP4, MOV and WebM to MKV keep only the first subtitle track (as ASS), and MP4 to WebM keeps the first one as WebVTT. Other pairs, including MKV to MP4 or MOV and WebM to MP4, drop subtitle tracks, and the converter does not burn them into the picture. Subtitles that are already burned in stay, because they are part of the video frames.
What about MKV attachments (fonts, cover art) when going WMV to FLV?
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MKV is the only mainstream container that stores arbitrary attached files (TTF fonts for ASS subs, JPG cover art, fan-translated PDF inserts). Going from WMV to FLV drops these attachments when FLV is not MKV — the elementary streams convert, but the attached payload stays in the source. Keep WMV as a backup if you depend on attached fonts.
Which codec does the FLV output use by default?
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It depends on the FLV container. MP4, MOV and MKV output use H.264, which plays on practically every phone, browser and TV. WebM output uses VP9. AVI, WMV and MPEG output use the older codecs those formats were designed for. FLV’s low per-packet overhead made it excellent at streaming over the unreliable connections of its era, and huge archives of it still exist.
How does HDR (HDR10, Dolby Vision) survive WMV to FLV?
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There is no HDR processing or tone mapping. When the video stream is copied (MKV to MP4 or MOV with the default settings), HDR10 passes through as it is. When the video is re-encoded, the HDR10 mastering metadata is dropped and Dolby Vision or HDR10+ data is not kept, and with a Quality, Resolution or Frame Rate setting some pairs also reduce the video to 8-bit colour, so an HDR WMV can look washed out in the FLV.
Why is my FLV file smaller / larger than the WMV after conversion?
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It depends on what happens to the video. MKV to MP4 or MOV with the default settings copies the video stream unchanged, so the size stays close to the source. Most other pairs re-encode it: a high-bitrate WMV usually comes out smaller, while an already heavily compressed one can grow. Smaller File under Quality gives the smallest output, and H.265 in the Codec setting (MP4, MOV and MKV) is usually smaller than H.264 at similar quality but plays on fewer devices.
