Have you ever come across a file with a really strange extension? And there is no way that you can figure out what kind of file it is? Well, we often come across so many types of files. Sometimes, we know what those extensions define. But, more often than not, we don’t. And that’s absolutely normal, especially because there are thousands of file formats.

Let’s say, a file has the extension doc or docx (characters following the last period in the file name), you know that you will need Microsoft Office or one of its alternative productivity suites, such as Google Doc, to view as well as edit it. But what if the file extension is one you’ve never seen before? Or maybe one for which your computer can’t find the right software?

In this article we’ll guide you through how you can check a file for extension online. We believe that by the end of this article, we will have made your life a lot simpler with our tips.

File type- Definition

The file type or format refers to a file’s structure, which instructs a programme on how to display its contents. A Microsoft Word document, for example, saved in the word file extensions .doc or .docx.

working on files on laptop

Microsoft Word is the finest programme for viewing DOC files. Even if another application can open the file, it might not have all of the necessary functionality to display it appropriately.

Before we begin discussing about how we can check for a file extension online, or how to identify the file extension in computer, let’s clear our basics. What is a file extension exactly? Let’s get to that now.

What are common file extensions?

The file extension name is a suffix that is appended to the end of a file name to indicate what type of file it is. The extensions of various file formats are very different.

Image files, for example, can have extensions such as JPG, JPEG, and PNG. Similarly, different extensions indicate the file type in other document files. The extensions are prefixed by a dot, such as .pdf, .xls, and .doc for PDF, Excel sheet, and Word Document, respectively. MP4, MKV, AVI, FLV, and other video file extensions exist.

File types

But the list of the types of file extensions does not end here. That is what makes it so much more difficult for all of us to identify the type of any file with ease.

The following is a list of the most frequent file formats you’ll come across while working on a computer.

Text files can have these extensions - .ASC, .DOC, .DOCX, .RTF, .MSG, .PDF, .TXT, .WPD, .WPS. Image files can have the extensions, .BMP, .EPS, .GIF, .JPG, .PICT, .PNG, .PSD, .TIF, .WEBP etc. Sound file formats can have the .AAC, .AU, .MID, .MP3, .RA, .SND, .WMA, .WAV, extensions. Video files include .AVI, .MP4, .MPG, .MOV, .WMV extensions. Program files have .BAT, .COM, AND .EXE as extensions. Compressed files have the extensions - .ARC, .ARJ, .GZ, .HQX, .RAR, .SIT, .TAR, .Z, .ZIP, etc.

Detecting file types with the help of our tool

Our tool is called the File Type Checker. It is absolutely free to use, and 100% online. It has a very simple user interface, and all you need to do is, upload the file you want to check the type of. It could also be a file without any extension.

This tool is completely platform independent. It works on all Operating systems and can be used without any downloads at all.

File type checker tool

We place a high value on the privacy of our visitors. Your files are not uploaded because we use cloud storage. As a result, there is no risk of a data leak. Your information is by all means, safe and secure with us.

At the same time, you not only learn the file type, but you also learn about complex topics such as the MIME type and other possible extensions.

How to use our File Type Checker tool?

Our tool lets you check the file for extension online. It is completely free and you can check as many files as you desire. It provides cross platform support, so you can access it from your phone, laptop, anywhere.

The steps you need to follow are-

  • Choose and upload your file on our website.
  • It gets uploaded to the cloud and hence it doesn’t get saved to our database at all.
  • After uploading, which takes zero to few seconds depending on the file size and your internet connectivity, our website instantly displays the results.
  • It displays the file name, file extension, mime type, and advanced information.
  • To display the advanced information, you just need to click on the question mark.
  • The advanced information displayed includes many more possible extensions, mime types, and also the file signature.

How to use file type checker

Using our tool is not at all difficult per se. You don’t need to be tech- savvy, or you don’t even need to have any knowledge of file formats and file extensions as such. You simply need a good internet connection and you are good to go.


We hope that with this article, you now have the basic idea of what file extensions are. We also hope our article has provided you with a foundational idea on the various common file extensions that we use every day.

You can research on the file types by yourselves on the internet, or you can use online tools like our File Type Checker to check the type of file. You can also give our article on “How to open a file with no extension or unknown extension?” a short read for more insight.