Have you ever encountered a scenario where you end up with a file without an extension? How are you going to open it? One way is to just guess and try to change the file extension to different file types and try to open the file.
This sometimes works if someone says they are sending you a Word document by email, but for some reason the file does not have an extension. Obviously you can just try the .doc or .docx extension and it will probably open.
But if you don’t know what type of file it is, trying different extensions is a waste of time. Also, you may not have an installed program associated with the file type, so even if you changed it to the correct one, it might still not open.
For example, if a file does indeed have a PSD extension and you try to open it without Photoshop installed, you might mistakenly conclude that it is the wrong file extension.
In this article, I will show you a quick and more accurate way to determine the type of file you might have. For this I created a couple of test files and then removed the file extensions.
I created a Word document, PDF file and image file for demo purposes. Obviously, your file may be of a different type, but the procedure will be the same for any type of file.
Install HEX Editor
Yes, the HEX editor may seem insanely geeky and technical, but it really isn’t that bad. There is a free program called XVI32 that doesn’t even need to be installed to use it.
You can just download it and run the EXE file! This is what the main interface looks like after opening it.
On the left is the Hexadecimal Viewer and on the right is the Data Inspector, which basically converts Hexadecimal values ??to actual data values. On the hex side, it’s almost impossible to figure out anything, so don’t even worry about it.
Most of the data-side data won’t make sense either, but there will usually be a few key pieces of text that tell you which file you’re working with. In my first example, I opened a Word document that had the .docx extension removed. This is how it looked in XVI32:
First of all, you need to look at the very top of the data inspector. As you can see, we can see .XML, which means it is an XML file. But wait, you say, isn’t this a Word document?
Technically, all text documents in Office 2010 are XML files. All of the content in a Word document is actually stored inside the underlying XML file, which is why you see it there.
However, if you scroll down a bit in the Data Inspector, you will see the following at the end of one of the sections of the paragraph:
Finally, you see “word†and “document†which tell you that this is a Word document. Some file types, such as Word documents, are a little more difficult to understand due to the basic structure of XML, but you just have to keep scrolling and searching and you’ll figure it out.
The rest of the file types are really simple. For example, this is what I get when I open a PDF file in XVI32:
The top right of the first line is PDF, so you know you are working with a PDF file. Super easy! And this is what it looks like when you open a PNG image file:
Again, this is very easy to understand since the PNG is written right at the very top of the file. As a final example, I also decided to try an MP3 file to see what it looks like.
This one was a little tricky, but if you look at the very top and google any three or four letter combinations that only occur in capital letters, you can figure it out.
As you can see, ID3 appears on the very first line. Even though there is no MP3 in it, ID3 gives you an important hint because ID3 is the metadata that stores all the information about a music file, such as artist, title, album, year, etc.
So from seeing the ID3, you can guess it is an MP3 file. In addition, you see other clues such as “Ninja Tune Records” which means it is probably some kind of audio file.
Overall, I think this is a much better way to figure out how to open a file without the file extension, rather than randomly trying different file extensions. If you still can’t figure out which file you have, please leave a comment and I’ll try to help. Enjoy!
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