Video Format Comparison

FLV vs WebM: Flash Video vs Modern Web Video

FLV (Flash Video) was the dominant web video format from 2000–2015, used by YouTube (until 2015), Facebook, and virtually every video website. It required Adobe Flash Player for playback. When Flash was deprecated in 2017 and killed by Adobe in 2020, FLV died with it. WebM emerged in 2010 as the open-source HTML5 alternative, and with Flash's death became the royalty-free web video standard alongside MP4. FLV is now a legacy archive format — all new web video should use MP4 or WebM.

FLVvsWebM

Quick Verdict

Use FLV when…

Use FLV only if you have legacy content in FLV format that needs to be served to very old systems. There is no reason to create new FLV content in 2024.

Use WebM when…

Use WebM for all web video — royalty-free, natively supported by all modern browsers, excellent quality, and purpose-built for HTTP streaming.

FLV vs WebM: Feature Comparison

Feature	FLV	WebM
Browser support	No native support (Flash dead since 2020)	Chrome, Firefox, Edge, Safari 16+
Video codecs	Sorenson Spark, H.263, VP6, H.264	VP8, VP9, AV1
Flash required	Yes (Adobe Flash Player)	No — native HTML5
Mobile support	Never worked on iOS; Android dropped 2012	All modern mobile browsers
Streaming	RTMP protocol (legacy CDN)	HTTP/DASH (modern CDN)
File size	Codec-dependent	Excellent (VP9/AV1 are very efficient)
Created	Macromedia/Adobe (1996)	Google (2010)

When FLV wins

✓Browser support: No native support (Flash dead since 2020)
✓Video codecs: Sorenson Spark, H.263, VP6, H.264
✓Flash required: Yes (Adobe Flash Player)

When WebM wins

✓Browser support: Chrome, Firefox, Edge, Safari 16+
✓Video codecs: VP8, VP9, AV1
✓Flash required: No — native HTML5

Frequently asked questions

Can I still play FLV files?

Yes, via dedicated apps. VLC plays FLV natively on all platforms. ffplay (part of FFmpeg) plays FLV. Web browsers no longer play FLV since Flash is dead. For embedding on websites, convert FLV to MP4 or WebM.

How do I convert FLV to WebM?

FFmpeg: ffmpeg -i input.flv -c:v libvpx-vp9 -b:v 0 -crf 33 -c:a libopus output.webm. For faster conversion: ffmpeg -i input.flv -c:v libvpx -quality good -b:v 1M -c:a libvorbis output.webm (VP8/Vorbis is faster to encode than VP9/Opus).