WMV to FLV Converter

How to Convert WMV to FLV Online

1. Upload Your WMV File: Drag and drop or click "+ Add Files" to pick one or more .wmv clips. Batch upload is supported — every file inherits the same output settings.
2. Pick Quality Preset or Target Size: Default is "Very High (Recommended)" which re-encodes to FLV's H.264 video layer at a balanced bitrate. Pick a lower preset for smaller files, or switch to "Specific file size" to cap output bytes, "Constant Bitrate" for streaming-friendly fixed rate, or "Constant Quality" / "Constraint Quality" for CRF-style quality targeting.
3. Resize or Trim (Optional): Under Video resolution, keep original, pick a Preset Resolution (240p through 4K), enter Width × Height, or scale by Resolution Percentage. Use Trim → Time Range to clip a start and end timestamp before encoding.
4. Convert and Download: Click Convert. Files process in your browser session — no sign-up, no watermark, and your source clip never leaves a public upload bucket.

Why Convert WMV to FLV?

WMV (Windows Media Video) was introduced by Microsoft in 1999 and wraps WMV1/WMV2/WMV3/VC-1 video inside the ASF container. FLV (Flash Video) launched with Flash Player 7 in September 2003 and traditionally carried Sorenson Spark, On2 VP6, or — after Flash Player 9 Update 3 in December 2007 — H.264 video. Adobe ended Flash Player support on December 31, 2020 and began blocking Flash content on January 12, 2021, so FLV is now a legacy delivery format. Most modern workflows prefer MP4 instead, but FLV remains a valid choice in narrow scenarios where the downstream system explicitly expects an FLV stream.

• Feeding legacy e-learning or LMS players — Some older SCORM packages, internal training portals, and intranet CMSes still embed Flash-era video players (JW Player FLV mode, Flowplayer Flash, Strobe Media Playback) that read .flv but not .wmv. Re-wrapping a WMV recording into FLV keeps the existing course working without rebuilding the player.
• RTMP ingest and old streaming servers — Wowza Streaming Engine, Red5, and legacy Adobe Media Server installations natively handle FLV/RTMP streams. WMV's Windows Media Services delivery has been deprecated since Windows Server 2008, so re-encoding to FLV is sometimes the bridge to a still-running RTMP origin.
• Cross-platform replacement for WMV on macOS/Linux — WMV playback on macOS ended with the discontinuation of Flip4Mac/Windows Media Components, and Linux relies on FFmpeg-based players. FLV is decoded out-of-the-box by VLC, MPV, and FFmpeg on every desktop OS, which makes it a more portable archival container than ASF/WMV.
• Game engine cutscenes and old video tools — Adobe Animate, older Captivate projects, and a handful of Flash-based game engines (Stencyl, Flixel) still import FLV for video sprites and cutscenes. They cannot consume WMV directly.
• Re-encoding to standardize a mixed archive — If you already maintain an FLV-based catalog from the late 2000s, converting incoming WMV submissions to FLV keeps the archive homogeneous and lets a single player handle every clip.

WMV vs FLV — Format Comparison

FLV Video Codec Quick Guide

When converting to FLV, the embedded codec matters as much as the container. Pick based on what your target player actually decodes:

xconvert's FLV output defaults to H.264 video with an AAC or MP3 audio track, which works with every Flash Player from 9.0.115 onward and with any FFmpeg-based decoder (VLC, MPV, ffplay).

Frequently Asked Questions

Should I really still be using FLV in 2026?

Probably not, unless a specific downstream system requires it. Adobe Flash Player reached end of life on December 31, 2020, and no modern browser plays FLV natively. The legitimate reasons to convert to FLV today are: feeding a still-running RTMP server, importing into Adobe Animate, populating a legacy LMS that expects .flv, or maintaining consistency with an existing FLV archive. For everything else — sharing, web embedding, social uploads — convert WMV to MP4 or WebM instead.

Will the output FLV play in my browser?

Not directly. All major browsers (Chrome, Firefox, Edge, Safari) removed Flash support in late 2020 / early 2021, and <video> elements do not recognize the video/x-flv MIME type. To play an FLV file you need VLC, MPV, an FFmpeg-based decoder, an RTMP-aware streaming server, or a desktop tool like K-Lite Codec Pack with Media Player Classic. If you need browser playback, pick MP4 instead.

What codec does the resulting FLV use?

By default, xconvert encodes the FLV video stream as H.264 (AVC) and the audio as AAC. H.264-in-FLV requires Flash Player 9 Update 3 (December 2007) or any modern FFmpeg-based decoder. If you specifically need a Spark/VP6 FLV for a Flash 6/7 player, you'll need a desktop encoder — most online tools, including this one, target the H.264 profile because it matches the quality and bitrate of modern MP4 output.

Why is the FLV smaller (or larger) than the source WMV?

Because the codecs differ. A WMV file commonly uses WMV3 or VC-1; an FLV typically uses H.264. H.264 compresses 15-30% more efficiently than WMV3 at the same visual quality, so a WMV→FLV conversion with default settings usually shrinks the file by roughly that margin. If you raise the bitrate, switch to a lossless-leaning preset, or upscale, the output can end up larger.

Can I keep the original WMV resolution and bitrate?

Yes. In Video resolution, choose "Keep original" to preserve the source dimensions. In File Compression, pick "Constant Quality" with a Very High preset to closely match the source bitrate. The resulting FLV will be visually near-identical to the WMV, though some quality is always lost when transcoding between two different codecs.

Does conversion happen in my browser or on a server?

Your file uploads over HTTPS to xconvert's processing edge, runs through FFmpeg there, and the result is returned to your browser. Source and output files are auto-deleted shortly after the session ends. Nothing is shared, sold, or indexed. If you'd rather process locally, FFmpeg's command line equivalent is ffmpeg -i input.wmv -c:v libx264 -c:a aac output.flv.

Will subtitles, chapters, or DRM transfer from WMV to FLV?

No. FLV has no chapter or subtitle structure — it only carries video, audio, and freeform metadata tags. Any soft-subtitle stream or ASF script command in the source WMV is dropped during conversion. If the source WMV is DRM-protected (PlayReady, Windows Media DRM), it cannot be re-encoded — the file must be DRM-free.

What's the file size limit for free conversions?

xconvert's free tier handles single uploads up to roughly 1 GB; larger files require an account. Most 1080p WMV files under 30 minutes fit well within the free limit. For batches, the total queue is processed sequentially and there is no daily file-count cap.

Can I convert FLV back to WMV, or to MP4 later?

Yes. xconvert offers FLV to WMV for the reverse direction, FLV to MP4 to modernize for web playback, and FLV to MOV for editing in Final Cut or QuickTime-aware tools. Round-tripping always loses a small amount of quality, so when possible keep an unencoded copy of the original WMV.