FileKeeps

Play FLV

Play Flash-era FLV videos without a plugin. Converted to MP4 on your device.

On-Device

Drop a folder or files here

JPG · PNG · WebP · GIF · BMP · AVIF · SVG · HEIC · PSD · AI · TIFF · camera RAW · PDF · HWP · Word · PPT · Excel · DWG/DXF · MP4/WebM/MOV/MKV/AVI/WMV · MP3/WAV/WMA/AIFF · TXT/MD/CSV/JSON/HTML — subfolders included

This browser doesn't support the folder-open dialog, so the standard folder picker is used. Files are read only on your device.

FLV is the Flash-video format common in clips downloaded from the web between 2005 and 2015. With Flash gone, browsers can't open FLV. This page remuxes or converts FLV to MP4 on your device and plays it.

How to use it

  1. 1Click 'Choose FLV files' or drop files onto the page. A whole folder works too.
  2. 2Click a file in the grid to start preparation — the container is first remuxed to MP4 (a few seconds), and if the browser can't decode that codec it is converted automatically with a progress indicator.
  3. 3Once ready it plays in place. ← → for the next file, F for full screen, Esc back to the grid.

How it works

If the video inside is H.264 (most files after 2008) it is only remuxed to MP4 and plays within seconds. Older Sorenson H.263 and VP6 video can't be drawn by the browser and is converted to H.264. MP3 and AAC audio is kept or becomes AAC.

Preparation runs on ffmpeg.wasm inside the browser. The engine (about 30 MB) is downloaded once on first use and cached after that. Prepared results are held in memory briefly and vanish when the tab closes. Files over 900 MB don't fit in browser memory — convert them first with the Video Converter tool.

Limits

VP6 alpha (transparent) video shows on a black background since MP4 has no alpha. FLV files cut off mid-stream play only the leading part or fail. Old codecs (Sorenson, VP6, Nellymoser, Speex) need conversion, which takes time proportional to length.

Good for

Checking FLV in an old downloads folder, opening Flash-era lecture material, and previewing before converting to MP4.

Frequently asked questions

How do I save FLV as MP4?+

Video Converter, FLV → MP4. With H.264 video it's a remux, so it finishes fast with no quality loss.

Does F4V work?+

F4V is really an MP4 variant; renaming the extension to .mp4 usually makes it play as-is. Try renaming before dropping it in.

Can I make a GIF from it?+

The GIF Maker tool cuts a range into a GIF. Use this viewer first to find the moment you want.