Convert Flash Video (.f4v) to Flash Video (.flv) 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 .flv file when it's ready.
F4V and FLV are both Adobe Flash video formats, but they differ fundamentally in their container structure and codec support. FLV (Flash Video) is the original Flash container from 2002, using Sorenson Spark or VP6 video with MP3 or Nellymoser audio. F4V replaced FLV in 2007, adopting the ISO base media file format with H.264/AAC — essentially an MP4 variant with Flash metadata. Converting F4V to FLV moves content from the newer Flash container back to the legacy format.
The main reason to convert F4V to FLV is compatibility with older Flash-based systems that specifically require the FLV container. Some legacy media servers (Red5, Wowza with old configurations), Flash-based video players still running in isolated environments, and archival systems catalog content by the .flv extension. While both formats are technically obsolete, FLV has broader recognition in legacy tooling and some streaming workflows.
FFmpeg reads the H.264/AAC streams from the F4V ISO BMFF container and re-muxes or re-encodes them into the FLV container. Since FLV supports H.264 (via extended codec tag) and AAC natively in most modern FLV implementations, a direct stream copy is often possible. For strict legacy FLV compatibility (older Flash Player versions), re-encoding to VP6 video and MP3 audio may be necessary. The FLV container uses a simple tag-based structure with metadata stored as AMF (ActionScript Message Format) objects.
When stream copying H.264/AAC into FLV, quality is identical to the source — zero loss. If re-encoding to VP6 for legacy Flash compatibility, expect visible quality degradation as VP6 is significantly less efficient than H.264. MP3 audio at matched bitrate is comparable to AAC for most content.
| Device | F4V | FLV |
|---|---|---|
| Windows PC | Partial | Partial |
| macOS | Partial | Partial |
| iPhone/iPad | Partial | Partial |
| Android | Partial | Partial |
| Linux | Partial | Partial |
| 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
F4V to FLV conversion is a niche but sometimes necessary operation for maintaining legacy Flash infrastructure. Stream copying preserves quality, while VP6 re-encoding trades quality for the broadest legacy Flash compatibility.
Безпечна передача
Завантаження зашифровані через HTTPS
Конфіденційність передусім
Файли автоматично видаляються після обробки
Без реєстрації
Почніть конвертацію миттєво
Працює всюди
| No |
8MB free, 50MB Nitro
Будь-який браузер, будь-який пристрій
| Характеристика | F4V | FLV |
|---|---|---|
| Повна назва | Flash MP4 Video | Flash Video |
| Розширення | .f4v | .flv |
| Найкраще для | MPEG-4 based | Small file size |