What is an ASAX file?
An .ASAX file is an ASP.NET Server Application File created by Microsoft. It is most commonly known as the global application file (often named `Global.asax`). Web developers use this file to handle application-level and session-level events in ASP.NET web applications. The file contains server-side code written in C# or VB.NET, which executes on the web server rather than the user's browser.
How to open ASAX files?
Because .ASAX files store plain text source code, you can open them with any standard code editor. The primary software designed to build and manage these files is Microsoft Visual Studio. Other popular text editors like Visual Studio Code, Notepad++, or Sublime Text can also read, edit, and save the .ASAX format perfectly.
Best practices and troubleshooting
If you double-click an .ASAX file on a standard computer, the operating system usually does not know which program to use. You can resolve this by right-clicking the file and assigning it to your preferred text editor. You should never upload raw .ASAX files directly to a public web server folder without proper IIS configuration. Doing so is a major security risk. The web server must process the code, not serve the source file as plain text to visitors.
View ASAX files online
viewer.online/asax analyzes .ASAX files to identify their exact format and creator software, shows which programs can open the file, and usually previews it. Because .ASAX files use the known Source format, viewer.online/asax can safely open and display them online, eliminating compatibility problems entirely.