How To Open A File Without Knowing The Extension

Date: Nov 3, 2021

How To Open A File Without Knowing The Extension

There are times when you may come across a file and it has no extension making opening it with the right application a trying experience. Trying to work out which application to use can be very frustrating and time consuming so instead of wasting time, try the following tip:

First check that the file has no extension by doing the following:

  • Right-click on the file, click on “Properties” and “type of file” should be displayed on the “General” tab of file properties. Note: if it just says “File” then it has no file extension, or....
  • Check the file extension from the “Type” column in Windows file explorer when files are displayed in “List view”, or.…
  • Select the “View” tab from the top ribbon bar and check the box beside “File name extension”

If the file has an extension listed but you can’t open it, this is likely to be because you don’t have the associated program installed on your computer or device.

Different ways to identify the application needed to open it include:

  • In a browser, go to (, enter your file name’s extension in the search bar, and choose and install one of the suggested programs associated with that file extension
  • In a browser, go to ( and drag and drop the file into the browser for the website to identify it.
  • Open a browser and download the UK government’s DROID tool available here ( and use that to identify the file extension listed in the “Format” column
  • Use a hex editor, such as Free Hex Editor Neo which can be downloaded from here:( and then after opening the hex editor, open the file, scroll to the right end of the block of numbers, and you will see the file extension associated with the file