Show file extension on Windows
First, let's see how to show file extension on systems Windows. The procedure to follow varies slightly depending on the version of the operating system used.
Windows 10 / 8.x
If you are using a recent version of Windows, for example Windows 10 o Windows 8.x, you can enable the display of file extensions by opening theFile Explorer (the yellow folder icon at the bottom left of the taskbar), by clicking on the tab Show that you find at the top left and putting the check mark next to the option Extensions file names.
Alternatively, if you prefer, you can get the same result by clicking on the button Fillet which is located at the top left of theFile Explorer and selecting the voice Change folder and search options from the menu that appears. In the window that opens, you must then select the tab viewing, remove the check mark from the item Hide extensions for known file types and click on the button Apply per salvare i Cambiomenti.
In case of second thoughts - almost needless to say - you can hide the display of file extensions again by clicking on the tab Show in the File Explorer and unchecking the option Extensions file names or, if you prefer, by going to the menu File> Change Folder and Search Options, selecting the scheda viewing from the window that opens and putting the check mark next to the option Hide extensions for known file types.
Windows 7 / Vista
If you want to find out how to view the file extension on Windows 7 or Vista, know that you just need to follow a procedure very similar to the one just seen for Windows 10. Then open theExplore Resources Windows by selecting the icon gialla poster located at the bottom left of the taskbar, click on the button Organize located at the top left of the window that opens and select the item Folder and search options in the menu that appears.
At this point, click on the tab viewing, remove the check mark next to the item Hide extensions for known file types click her cousin Apply and then OK to save the changes. Finished! You have now enabled the display of extensions for all file types.
In case you want to go back and hide the file extensions again, go back to Folder optionsclick here viewingand put the check mark next to the item again Hide extensions for known file types. Simple, isn't it?
Windows XP
If you still use the good old Windows XP (you shouldn't do this, it's an outdated and unsafe operating system!), to integrate extensions into file names you have to open any folder and click on the item Folder options present in the menu Instruments.
In the window that opens, click on the tab viewing, remove the check mark next to the item Hide extensions for known file types click her cousin Apply and then OK per salvare i Cambiomenti.

Et voila! Now, all extensions will be displayed at the end of the filenames. You will then find the extension .doc after the name of the Word files, the extensions .jpg / .bmp / .gif, etc. after the name of the images, .mp3 in the names of your songs and so on.
If you have second thoughts, you can retrace your steps simply by returning to the menu Tools> Folder Options Explorer, by selecting the tab viewing from the window that opens and placing the check mark next to the item Hide extensions for known file types.
Show file extension on Mac
I use a Mac? No problem. MacOS also allows you to show file extensions in a very simple way. All you have to do is go to the Desk (or open the Finder) and will select the voice Pref Renze from the menu Finder which is located at the top left.
In the window that opens, select the tab Advanced, metti il segno di spunta accanto alla voce Show all filename extensions And that's it. By doing this you have enabled the display of extensions for all file types.
In case of second thoughts, if you want to retrace your steps and hide the file extensions again, go to the menu again Finder> Preferences, select the scheda Advanced from the window that opens and remove the check mark from the item Show all filename extensions.
Show file extension on Linux
Now let's move on to Ubuntu, one of the most popular distributions of the Linux operating system. If you have an Ubuntu-equipped PC and want to automatically show the extension for all file types, know that… you don't have to do anything!
The desktop environments commonly used by Linux distros, in fact, analyze the contents of the files and try to "guess" their type thanks to a heuristic system. This means that extensions are not used to determine the type of a file: they are shown simply as a suffix of the name and therefore their display is already active by default.
In reality, macOS also behaves in a similar way, but for convenience and to better accustom the "switchers" that come from Windows, it offers a function to show and hide file extensions in the Finder.
Identify file extensions
Have you found a file that has an extension unknown to you and would like to find out which program to open it with? No problem, by connecting to this Wikipedia page (in English) you can find a very long list of file extensions and their "identity".
Alternatively, you can rely on services such as OpenTheFile and File-Extensions.org, which allow you to identify file extensions and suggest a list of applications with which to open them. Their operation is quite intuitive: all you have to do is connect to their home pages, type the extension to be identified (eg. docx) in the search bar and press the button Submit sulla tastiera from the PC.
As already mentioned, you will be shown a page with a description of the type of file associated with the extension you searched for and, further down, a list of applications that allow you to deal with the types of files in question. Personally I do not recommend you to download the programs using the links provided directly by these sites (as they could be promotional links), but if you search for the programs on Google and download them from their respective official sites you should have no problems.
Do you want to change the association of a file type so that it is opened by software other than the one currently set as default? This too can be done in a very simple way: read my tutorial on how to change the default program and find out all the steps to take.
How to show file extension