FLV (Flash Video)
FLV is the Flash Video container that powered online video in the 2000s through Adobe Flash Player. It was used by early YouTube, Hulu, and most video sharing sites before the HTML5 transition. FLV is effectively obsolete since Flash was discontinued in 2020.
MIME Type
video/x-flv
Type
Binary
Compression
Lossy
Advantages
- + Historically important for web video streaming
- + Simple container structure that is easy to parse
- + Supported by FFmpeg for conversion to modern formats
Disadvantages
- − Flash Player is discontinued — FLV cannot play in browsers
- − No native support in modern operating systems or devices
- − H.264/AAC in FLV is better served in MP4 containers
When to Use .FLV
Do not use FLV for new projects. Convert existing FLV files to MP4 to ensure playback on modern browsers and devices.
Technical Details
FLV uses a simple tag-based structure with interleaved audio and video packets. It supports Sorenson Spark, VP6, and H.264 video with MP3 or AAC audio. Metadata is stored in an onMetaData script tag.
History
Macromedia introduced FLV in 2002 with Flash MX. Adobe acquired Flash in 2005 and continued FLV through 2020 when Flash Player reached end of life. HTML5 video (MP4/WebM) has completely replaced FLV on the web.