Recently, I came across a trouble where I had to modify the file extension on a agglomeration of Windows files from no extension to .JPG. Someone sent me a large number of files, but for some foreign reason, they had no file extension, even though they were images! One time I added the .JPG extension to the stop of the file, I was able to open up the images.

At that place are many other reasons why you may demand to rename file extensions, so I'll show you how you lot tin change them one at a fourth dimension if yous have a small-scale number of files or batch rename file extensions if you have lots of files.

If you have a file with no extension, Windows will probably assign a generic icon to it. When you endeavour to open it, the Open With dialog volition pop up where you'll get a list of programs to choose from.

file extensions

Obviously, since in that location is no file extension for the file, Windows is not able to determine which program should open up it. If you lot want to change the file extension for the file, you starting time need to be able to encounter file extensions in Windows. You can do this by going to My Computer and and so going to Tools and Folder Options.

tool folder options

In Windows vii, click on the Organize button and then click Folder and search options.

folder and search options

In Windows 8, you only click on the View tab in Explorer and check the File proper name extensions box.

file name extensions

Go to the View tab and scroll downward till you lot encounter the option "Hide extensions for known file types". Go alee and uncheck it.

hide extensions windows

If the file has no extension at all, this step may not be necessary, but I am including it because if y'all're trying to Change the file type from one type to another, so you need to practice this. Now correct-click on your file and choose Rename.

reanme files

Motility to the terminate of the name and type in .XXX or whatsoever the blazon is for the file you lot want information technology to be, i.e. .TXT for text files, .XLS for Excel files, etc. Obviously, the file has to have originally been from that program that you are changing the file extension too. In my case, the text file was from Excel, so I added that extension back.

rename file

How to Batch Rename File Extensions

So how do yous rename multiple file extensions at in one case? If you have a directory full of files that need to be changed from .PNG to .JPG, it'due south going to take forever to do this using the method above. Luckily, there are a couple of different ways we can change the file extension for multiple files at once.

Command Line

For those of y'all who are familiar with the control line, there is a very easy command you can use to perform very uncomplicated file renaming tasks. In that location are two commands that you can apply at the command prompt: ren and rename. Both of them do the exact same matter, and then information technology's just a preference as to which one you use.

If you lot have a binder with a agglomeration of JPGs inside and you want to change the file extension to PNG, for example, you lot would type in the following command:

ren *.jpg *.png

rename files

Every bit yous can meet above, the command inverse all the files in that directory with a JPG file extension to ones with a PNG file extension. Yous tin can get more information on how to apply the ren command from Microsoft's website.

Majority Rename Utility

If the control line sounds daunting, then in that location are a couple of useful file renaming utilities that will become the job done for you with only a few clicks. One of my favorites is the Bulk Rename Utility because it is the single almost comprehensive file renaming utility out there.

bulk rename utility

Yes, the interface is admittedly jammed pack with options that make little to no sense unless you read all the document from the website. Withal, for our purpose, all we have to worry about is the box labeled Extension (11) down at the bottom right. Change it from Aforementioned to Fixed and then type in the new extension you lot want. You'll see that the listing box will show you the new proper noun of the file instantly before you even commit the changes. Click the Rename push button and that's information technology.

I mentioned this tool even though it's overkill for our purpose considering it'due south a actually great utility and ane that some might be interested in learning if they want to rename thousands of photos with names likes DSC00x, IMG00x, etc.

Advanced Renamer

Some other skillful program that also requires a bit of reading to effigy out is Advanced Renamer. Thankfully, both sites take user guides and tutorials. As well, I'll explicate the procedure for irresolute the file extension hither. Once you install it, go ahead and click the Add push to add together their files or to add a binder, which will add all the files in that folder to the list.

advanced renamer

At present in order to perform any actions on that listing, you take to add together methods in the left manus pane. Yous can add together multiple methods to perform circuitous renaming of files and folders. We want to click Add Method and then cull New Proper name.

add renaming method

At present go ahead and type in the new extension yous would like into the box at the top and then alter the Apply to box at the lesser to Extension instead of Name.

change file extension

In the list of files, y'all should see the updated New Filename field updated with the changes to the file name or extension. When you have gotten it right the mode you like, go ahead and click on the Starting time Batch button.

rename files tool

Once more, I'thousand giving the simplest example with these programs, but you tin create far more complex renaming schemes if you like. If yous really don't care about all the actress functionality, and then check out the last program that does zippo but change the file extension.

Bulk Extension Changer

If yous want simple, Majority Extension Changer is the program for you lot. All you accept to practise is three things: get-go, pick the binder where the files are located, and then prepare the current and replacement extension and then but press the Go push.

bulk extension changer

The but selection is if you want to include sub-directories or non. In the 2nd pace, you lot tin can add together multiple replacement rules in case your binder has files of many different types and yous want to cheque several at once.

Hopefully, those are enough options for any need yous might have for renaming file extensions. If you lot have any questions, feel free to post a comment. Enjoy!