What is an ASP file?
An .ASP file is primarily an Active Server Page created for Microsoft web servers. It contains web page code, such as HTML mixed with VBScript or C#. A web server like Microsoft IIS reads this code to generate a dynamic web page for the user.
However, users often download an .ASP file by accident. When you download a document like a bank statement or an invoice, the web server might fail to provide the correct file extension. Instead of saving a .PDF, a .ZIP, or a .DOC file, your browser saves the file using the web address name, which often ends in .ASP. A very rare use of the .ASP extension is also for spectroscopy data files from PerkinElmer or Agilent ChemStation.
How to open ASP files?
If your .ASP file is a web script, you can open it with text editors like Notepad++ or Visual Studio Code.
If you downloaded the file expecting a document, it is likely a misnamed file. You can try renaming the extension from .ASP to .PDF or .HTML and opening it with your web browser or Adobe Acrobat. Because .ASP has multiple possible meanings, we recommend using viewer.online/asp to identify the actual format of your file.
Software and tools
For developers, standard code editors and web servers handle .ASP files. For standard users trying to view data, we recommend file conversion to sensible target formats like .PDF, .HTML, or .TXT on convert.guru.
Summary
viewer.online/asp analyzes .ASP files to identify their exact format and creator software, shows which programs can open the file, and usually previews it. Because many downloaded .ASP files actually use the known PDF format, viewer.online/asp can safely open and display them online, eliminating compatibility problems.