BRN File

What are BRN files and how to open them

Are you having problems opening a BRN 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 BRN files.

What is a BRN file?

BRN files have multiple uses, and BrainStorm Document is one of them. Read more about the other uses further down the page.

BrainStorm Document

BrainStorm Document files store structured outlines of ideas and related information in BrainStorm, a Windows mind-mapping and brainstorming tool for organizing thoughts into a tree of topics with subtopics. They are commonly used to build idea maps that include titles, indented child entries, links to files or web pages, images, and allow multiple views of the same content.

BrainStorm creates these files when a user saves their idea-map or outline into its native data format. Users can export or publish these documents to HTML for sharing or display in a browser. The BrainStorm application opens, edits, and navigates these outlines.

Files begin with a header signature A032 at the very start. After that the file encodes structural attributes that show when entries go deeper in outline levels or finish, plus per-entry attributes like marking, color (text and background in Windows COLORREF), text length (with special handling for entries longer than 127 bytes), read-only status or title flags, and then the entry text bytes.

How to open BRN files

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

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

Last updated: August 24, 2026

All known file formats using extension .BRN

While BrainStorm Document is a popular type of BRN-file, we know of 2 different uses of the .BRN file extension. Different software may use files with the same extension for different types of data.

Sunplus Burn Firmware Update

Sunplus Burn firmware update files hold camera firmware images produced by Sunplus (also branded iCatch) for updating device firmware. These files are prepared by Sunplus' own firmware tools and used with hardware (or production tools) that support "burning" firmware into internal flash memory. Their primary role is to replace or upgrade firmware on cameras or related image-processing devices.

Files are created by Sunplus's flash or burn utilities (sometimes called FRM or SPHOST.BRN) to package firmware and static resources together - bootloader, default firmware (kernel or embedded OS), and partitions for resources such as splash graphics or fonts. Devices perform ISP (in-system programming) or RSV ("Read-Save-Verify") operations with these packages. The firmware inside is not a user-modifiable file like an image or document but a binary blob used by embedded hardware. Third-party software can sometimes extract parts of these files for reverse engineering, but they do not form a standard filesystem and are not generally meant for manual editing or reading.

A technical identifier appears at the very start of these files. The first bytes read are ASCII "SUNPBURNFILE" (hex 53 55 4E 50 42 55 52 4E 20 46 49 4C 45) beginning at offset 0, which identifies them as Sunplus Burn Firmware Update files.

Various apps that use files with this extension

These apps are known to open certain types of BRN files. Remember, different programs may use BRN 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 BRN file formats, example files, or compatible programs. Please use the links below or email us at submit@file.org to discuss further.