What is a BROWSER file?
A file with .browser extension is used by ASP.NET web applications to determine the capability and configuration of web browsers. It contains information about the browser’s capabilities, limitations, and characteristics. These characteristics help the ASP.NET framework to recognize the requesting browser and present the webpage to users accordingly.
BROWSER File Format
BROWSER definition files are used by the ASP.NET application to determine the capabilities of the browser. It is information contained in this file that is used by the server to generate markup and other resources that are compatible with the requesting browser.
BROWSER files are saved in plain text file format. You can open a BROWSER file in text editors such as Notepad, Notepad++, Apple TextEdit and Visual Studio IDE.
File Structure of BROWSER File Format
The BROWSER definition files use a hierarchical structure. Each .browser file contains an XML markup that includes the capabilities and features of a particular browser or a group of browsers. These details include characteristics such as agent string, version numbers, and support for technologies such as JavaScript, CSS, or other HTML elements. By using these browser definition files, ASP.NET developers customize user experiences based on the capabilities of different browsers.
Key Characteristics of the BROWSER File Format
| Characteristic | Description |
|---|---|
| File Extension | .browser |
| System-Generated & Managed | It is automatically created and updated by the Windows Computer Browser service; manual editing is rare and generally not recommended. |
| Legacy Technology Component | It is intrinsically linked to the legacy NetBIOS browser protocol, which has been largely superseded by technologies like Active Directory, DNS, and the Function Discovery service in modern Windows (Vista and later). |
| Local Scope | Its influence is typically limited to the local subnet, as the Browser service was not designed for large, routed networks without specific configuration. |
| Passive User Experience | End-users never directly interact with a .BROWSER file. Its effect is seen indirectly in the population of network resource lists. |
| Declining Relevance | In contemporary Windows networks (post Windows XP/Server 2003), the Browser service is often disabled by default, and the BROWSER file holds little to no operational significance. Modern discovery uses protocols like WS-Discovery and LLMNR. |
FAQ
Q1: Can I open a .BROWSER file like a normal document?
A: While you can open it in Notepad as a text file, its contents are system-level configurations not intended for casual viewing or editing.
Q2: s a BROWSER file a security risk?
A: The file itself is low-risk, but the legacy Computer Browser service it supports can be a vector for network reconnaissance; disabling the service on modern networks is a common security practice.
Q3: Why don’t I see this file on my Windows 11 computer?
A: Modern Windows versions have deprecated the Computer Browser service; the file and the service are absent or disabled by default, as network discovery uses newer protocols.
Q4: Should I delete the BROWSER file if I find it?
A: Generally, no. It is a system file. If the related service is running, deleting it may cause it to be recreated. The proper method is to disable the “Computer Browser” service via Windows Services Manager.
Q5: Does this file have anything to do with web browsers like Chrome or Edge?
A: No, it is a coincidence of naming. This “BROWSER” refers to the network resource browsing service, not to World Wide Web browsers.
