What is an ASPX file?

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If you’ve ever wondered what an ASPX file is, then you’re not alone. Many users will have seen a file extension on a document, such as a word file. This typically has a .docx extension, which tells the computer what type of file it is. 

This same process applied to ASPX files. Fundamentally, it is a file format that is used by web servers to tell them what to do with a request from the internet. 

Active Server Page Extended (ASPX) is an open-source development framework used by web developers to generate dynamic web pages using the .Net and C# programming languages. 

ASPX is a development of ASP, the technology that came before ASPX, and is is designed for Microsoft's ASP.NET framework. It is also known as a .NET Web Form. 

Essentially, the .aspx suffix on a URL tells us that the web pages are constructed using ASPX.

ASPX files typically contain various scripts or other open-source files that web browsers - the end-user - receive from web servers and these are the components of the web service that deliver dynamic, modern-looking elements on a page.

End users normally shouldn’t see or interact with these file types during their online experience, but if they do it can indicate there is an error with the web service’s configuration.

How to open an ASPX file

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A common occurrence when downloading a file from the web and onto a Windows machine is that it downloads as a .aspx file when you were expecting something else, such as a PDF. In these cases, a quick workaround that often works is to simply rename the file and change the file type to the one you expected, such as .pdf.

But if it’s a true ASPX file you’re looking to open, there are several options out there. Microsoft initially intended for the file to be opened in its open-source integrated developer environment (IDE) Visual Studio Code, arguably the best option for the job. But other programs are out there, both free and paid-for, should you wish to use an alternative.

Using Adobe Dreamweaver to open ASPX files

One of the most popular web development platforms available is Adobe Dreamweaver. This can be used to open the ASPX files. The program can be used to make and publish web pages with HTML, CSS, and Javascript, among others, speedily and from anywhere.

It has a smart, simplified coding engine, with hints and tips to help users get to grips with HTML, CSS and other web standards. However, Adobe is a paid-for service and a subscription to Dreamweaver will set you back £19.97 per month.

Using Notepad++ to open ASPX files

You can use a free source code editor, such as Notepad++, to open ASPX files. This editor is a good replacement for Notepad and also supports several languages, including CGI format. Underpinning this coding app is Scintilla which was developed using C++. It is also a lot quicker in execution and tiny in size too as it uses Win32 API and STL.

Other types of ASPX files (and what you need to do with them)

As hinted at earlier, the .aspx at the end of a URL means that the page has been created using the ASP.NET framework. Users need not open it, the browser will do that automatically. The code within the document will be run by the web server that runs ASP.NET.

Should you desire to open and edit a .aspx file, Microsoft's free Visual Studio can be used to do so. A normal text editor can also open up such files.

How to convert an ASPX file to a PDF

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There are many different converters to change ASPX to PDF, but it's often simpler to just use a browser, like Chrome. The ASPX file just needs to be simply dragged and dropped into the browser bar where one would enter a URL. Once the new browser window opens, press CTRL+P to print. Under the destination of said printing window click on 'Change' and save it as a PDF.

Clare Hopping
Freelance writer

Clare is the founder of Blue Cactus Digital, a digital marketing company that helps ethical and sustainability-focused businesses grow their customer base.

Prior to becoming a marketer, Clare was a journalist, working at a range of mobile device-focused outlets including Know Your Mobile before moving into freelance life.

As a freelance writer, she drew on her expertise in mobility to write features and guides for ITPro, as well as regularly writing news stories on a wide range of topics.