Convert Flash Video (.f4v) to WebM Video (.webm) online for free. Fast, secure video conversion with no watermarks or registration.
Conversion settings — add a file to adjust
Upload your .f4v file by dragging it into the upload area or clicking to browse.
Choose your output settings. The default settings work great for most files.
Click Convert and download your .webm file when it's ready.
F4V is Adobe's MPEG-4 Flash video container with H.264/AAC streams. WebM is Google's open-source web video format using VP8 or VP9 video with Opus or Vorbis audio in a Matroska-based container. WebM is natively supported by Chrome, Firefox, Edge, and Opera without any codec licensing. Converting F4V to WebM transforms Flash video into the modern open web video standard.
WebM is the royalty-free alternative to MP4 for web video delivery. It is the preferred format for HTML5 video when you want to avoid H.264 licensing considerations. VP9 (the standard WebM video codec) delivers quality comparable to H.264 at 30-50% lower bitrates, reducing bandwidth costs for video hosting. WebM is also required for some platforms — Google's own services strongly prefer WebM for uploaded content.
FFmpeg decodes the H.264 video from the F4V container and re-encodes it using libvpx-vp9 (VP9 encoder). Audio is transcoded from AAC to Opus using libopus — Opus is the state-of-the-art audio codec offering the best quality at any bitrate. VP9 encoding uses two-pass encoding for optimal bitrate distribution. The WebM container uses Matroska-based framing. CRF (Constant Rate Factor) mode with a target bitrate cap provides consistent quality across scenes.
VP9 at equivalent quality to the H.264 source typically produces files 30-50% smaller. At a CRF of 31 with a 2 Mbps target for 1080p, VP9 delivers excellent visual quality that rivals or exceeds the H.264 source. Opus audio at 128 kbps is superior to AAC at the same bitrate. The main tradeoff is encoding speed — VP9 is 5-10x slower to encode than H.264.
| Device | F4V | WebM |
|---|---|---|
| Windows PC | Partial | Partial |
| macOS | Partial | Partial |
| iPhone/iPad | Partial | Partial |
| Android | Partial | Native |
| Linux | Partial | Native |
| Web Browser | No |
Resolution: 1920x1080
Bitrate: 8-12 Mbps
H.264 recommended for fast processing
Resolution: 1080x1080
Bitrate: 3.5 Mbps
Square or 9:16 for Reels
Resolution: 1080x1920
Bitrate: 4 Mbps
9:16 vertical, under 60s ideal
Resolution: 1280x720
Bitrate: 5 Mbps
Under 140s, 512MB max
Resolution: 960x540
Bitrate: 2 Mbps
16MB limit for standard, 64MB for document
Resolution: 1280x720
Bitrate: 4 Mbps
8MB free, 50MB Nitro
F4V to WebM conversion produces modern, efficient, royalty-free web video. VP9's superior compression and Opus's excellent audio quality make WebM an outstanding choice for web delivery, open-source projects, and bandwidth-conscious hosting.
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| Native |
ทุกเบราว์เซอร์ ทุกอุปกรณ์
| ฟีเจอร์ | F4V | WebM |
|---|---|---|
| ชื่อเต็ม | Flash MP4 Video | WebM Video |
| นามสกุล | .f4v | .webm |
| เหมาะที่สุดสำหรับ | MPEG-4 based | Web optimized |