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File Extensions – Helpful and Not
File Extensions – Helpful and Not
Author: Jim Cerny, Forum Leader, Sarasota Technology
Users Group, Florida
October 2019 issue, Sarasota Monitor
www.thestug.org
jimcerny123 (at) gmail.com
So someone sends you a file attached to their email
– you try to open the file and you can’t, why is that?
I mean they obviously could open the file on their
computer, why couldn’t you open it on yours? Un-
fortunately, this is the frustrating part about FILE
EXTENSIONS (also known as “file types”).
If you use a program to CREATE a file, it is nice to
have the SAME PROGRAM to open or work with
the file you created. Naturally, if you use your com-
puter to create a file then your computer has the
program needed to open the file later. The problem
is when someone creates a file on their computer
and sends it to you – you need to have a program
that can open the file on your computer. Let’s look at
one example:
I have the Microsoft Word app (or program) on my
computer and I create a new document with it. I
save the document as a file, and the computer as-
signs it a “file extension” or “file type” of “.docx”. The
file extension is always the last three or four charac- There are probably many thousands of different file
ters of the file name right after the dot. This indi-
cates that this file was created using the latest ver- all. If you have any questions about a particular file
sion of Word. If I send this file (as an attachment to
an email) to someone else and they do NOT have
Word, they cannot open the file!
It is an option in Windows whether to display the file
extension, so your computer may not show you the
file extension as part of the file name. To see the file
extension when you use File Explorer, open the File
Explorer app, click on the “View” menu tab and
check the box labeled “File Name Extensions”. This
will display the file extensions (file type) as part of
the file name for all files.
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there are more options to open the file to READ it or
to EDIT it. Your computer may suggest some inter-
net sites or free apps that may be able to open the
file for you.
A good app like Microsoft Word may allow you to
save your file as a different type of file – so you can
pick one that is easier for more people to open. You
could save it as a “.pdf” or “.rtf” file type if you want.
A “.pdf” file can be opened by many apps but usual-
ly, the contents, or text, of the file can NOT be edit-
ed, only read. The “.rtf” file type (Rich Text File) can
also be opened by several other apps and can be
edited, BUT the text will have lost any formatting or
options used in Microsoft Word.
Are you working with photo files? Most photos or
pictures today are saved as a “.jpg” file type and any
app that can open or work with photos will be able to
open this file. That’s nice.
Here are just a few of the most popular file exten-
sions (types):
.doc or .docx – Microsoft Word
.html – webpage
.jpg – picture or photo image
.pdf – a document file that can be open or read by
many apps but cannot be edited
.rtf – rich text file that contains formatting (the Word-
pad app creates these files)
.txt – plain text file will no formatting
.xls and .xlsx – Microsoft Excel spreadsheet
types, but thankfully you do not have to know them
type, just Ask Google and you will find out what
apps could have created the file and which apps can
open or work with that file.
I know this all sounds a bit confusing, but you
should only run into a problem when you try to open
a file that you did not create on your computer.
Should this happen you may have to contact the
person who sent you the file and ask them to send it
to you again as a different file type – one that you
know you can open.