BS4 File

What are BS4 files and how to open them

Are you having problems opening a BS4 file or are you simply curious about its contents? We're here to explain the properties of these files and provide you with software that can open or handle your BS4 files.

What is a BS4 file?

A .BS4 file is a Mikogo Session Video Recording file.

Mikogo Session Video Recording files store desktop video recordings of online Mikogo sessions, capturing visual content shared by the presenter. These recordings are made by the Mikogo application during web conferencing or remote support sessions so that session history or demonstrations can be reviewed later. Motion on the presenter's screen is what gets recorded; audio is not captured.

Mikogo is both the writer and primary reader of these recordings: the Mikogo software creates files in this format, and playback is possible only using Mikogo Session Player (either as part of the Mikogo application bundle or as a separate utility). The recordings are not exportable into standard video formats. The format is proprietary and designed to meet audit compliance for Mikogo sessions.

Files begin with a unique binary signature - hex bytes EF CD AB 77 00 00 00 00 at offset zero, then sequences of zero bytes at offsets 10 and 25. These signatures help tools like TrID identify files of this type.

How to open BS4 files

Important: Different programs may use files with the BS4 file extension for different purposes, so unless you are sure which format your BS4 file is, you may need to try a few different programs.

While we have not verified the apps ourselves yet, our users have suggested five different BS4 openers which you will find listed below.

Last updated: August 25, 2026

Various apps that use files with this extension

These apps are known to open certain types of BS4 files. Remember, different programs may use BS4 files for different purposes, so you may need to try out a few of them to be able to open your specific file.

Help us help others

File.org helps thousands of users every day, and we would love to hear from you if you have additional information about BS4 file formats, example files, or compatible programs. Please use the links below or email us at submit@file.org to discuss further.