What Is an ASP File?

How to Open, Edit, and Convert ASP Files

Screenshot of several ASP files in Windows 10 that open with Notepad
ASP Files.

A file with the .ASP file extension is most likely an Active Server Page file, which is an ASP.NET web page provided by a Microsoft IIS server. The server processes scripts within the file and then generates HTML to display the page in the web browser.

ASP files are also called Classic ASP files, and normally use the VBScript language. Newer ASP.NET pages are saved with the ASPX file extension and are often written in C#.

A common place where you might see ".ASP" is at the very end of a URL that points to an ASP.NET web page, or when your web browser sends you an ASP file by accident instead of the actual file you were trying to download.

Other ASP files might be used by Adobe programs as an Adobe Color Separation Setup file, but the format might be obsolete and irrelevant with newer program versions. These files contain color options (like separation type, ink limit, and color types) that are used when exporting or printing a document.

How to Open Downloaded ASP Files

If you got an ASP file when you tried downloading something else (often a PDF), then there's a good chance that the server simply didn't name the file correctly.

For example, maybe you were trying to download a bank statement or some other document, and instead of having it open in your PDF viewer, it opens with a text editor or your computer doesn't know how to open it.

In this particular case, the server didn't append ".PDF" to the end of the file name, and instead used ".ASP" even though the actual file format is PDF. The easiest solution here is to just rename the file yourself, by erasing the last three letters after the period and putting in .PDF. For example, rename statement.asp to statement.pdf.

Note: This naming scheme is not how you actually convert one file format to another, but it's completely acceptable here since the file is truly in the PDF format but simply wasn't named appropriately. You're just completing the renaming step that the server didn't do itself.

How to Open Other ASP Files

Active Server Page files that end in .ASP are text files, meaning that they are fully readable (and editable) in a text editor like Notepad++, Brackets, or Sublime Text. Some alternative ASP editors include Microsoft Visual Studio and Adobe Dreamweaver.

A URL that ends with .ASP, like the one below, just means that the page is running in the ASP.NET framework. Your web browser does all the work to display it:

https://www.w3schools.com/asp/asp_introduction.asp

Since ASP files need to be parsed before being sent to a web browser, opening a local .ASP file in a web browser will just show you the text version, and won't actually render the HTML page. For that, you'd need to be running Microsoft IIS and open the page as localhost.

Tip: You can create ASP files from a blank document by just appending the .ASP file extension to the end of the file. This also works for converting HTML to ASP - just rename the extension from .HTML to .ASP.

Adobe Color Separation Setup files work with Adobe programs like Acrobat, Illustrator, and Photoshop.

How to Convert ASP Files

ASP files that are Active Server Page files can be converted to other formats but doing so would mean that the file would stop working the way it was intended to work. This is because the server that gives out the file needs it to be in the proper format in order to display pages correctly.

For example, converting the ASP file to HTML or PDF would let the file open in a web browser or PDF reader, but would also prevent it from working as an Active Server Page file if it were used on the web server.

If you do need to convert an ASP file, you can use Microsoft Visual Studio or Adobe Dreamweaver. Those programs will let you convert ASP to formats like HTML, ASPX, VBS, ASMX, JS, SRF, and more.

This online ASP to PHP converter can perform that conversion if you need the file to be in the PHP format.

More Information

The .ASP file extension closely resembles other extensions that have nothing to do with the formats mentioned on this page, and so won't open with the same programs linked above.

For example, APS files might look and sound a lot like ASP files but they are actually Greeting Card Studio Project files that are created and used by Greeting Card Studio.

Some technology terms use the ASP acronym too, but are not related to either of the ASP formats on this page. For example, ASP also stands for Application Service Provider, Analog Signal Processing, ATM Switch Processor, Addressable Scan Port, Advanced System Platform, and Auto-Speed Port.

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