Combine FLV Videos: Simple Software to Merge Multiple FLV Files

Best software to merge multiple FLV files into a single file

Below are reliable options (desktop and online), with short notes to help you choose.

Software	Platform	Key features	When to use
Wondershare UniConverter	Windows, macOS	Fast merging, convert to many formats, edit tools, “Merge All” option	If you want an easy GUI and format conversion
Avidemux	Windows, macOS, Linux	Free, supports FLV, simple join without re-encoding when codecs match	If you need a free, cross‑platform desktop tool
Andy’s FLV Joiner	Windows (portable)	Tiny, no install, designed specifically for FLV join/concatenate	For quick, simple FLV-only joins
GiliSoft Video Editor	Windows	FLV joiner module, preview, batch join	If you want a Windows-focused paid tool with a GUI
iDealshare VideoGo	Windows, macOS	Merge without re-encoding, many output formats	If you want flexible output format options
Clideo (online)	Web	No install, drag‑drop, basic transitions, converts formats	When you prefer an online tool and small/medium files
FFmpeg (command line)	Windows, macOS, Linux	Precise control, lossless concat when using correct method, free	If you want a free, scriptable, highest-control solution

Quick FFmpeg example (concatenate same-codec FLV files losslessly):

bash
# create files.txt listing:
# file ‘part1.flv’
# file ‘part2.flv’
ffmpeg -f concat -safe 0 -i files.txt -c copy output.flv

Recommendation: use Avidemux or FFmpeg for free lossless joins; use UniConverter or Clideo if you prefer a polished GUI and format conversion.