Common File Extensions
If you know how to recognize files by their extensions it will help you greatly when working with multiple programs and creating impressive content.
See the three file names in the image at the left. The letters after the dot in the file name is the file extension. It tells the computer which program to use to open that file. Extensions can also give you important information if you are familiar with them. (Note that school computers often won't show the file extension. You will see extensions when you save files and you'll see them on files you find online.)
There are probably thousands of file extensions, but common ones are listed below. If you pay attention to the type of files the programs use that you work with most, you will learn new ones as you need them.
If you are trying to memorize any of these, the extension and brief text that follows is probably sufficient. When you work with them enough you'll soon learn the other details that are included.
Here are some essential extensions everyone should be familiar with:
These extensions are also important, but you might not encounter them until you do more advanced work with digital media:
And here are two formats you might need to recognize when creating projects at school:
Some other important pieces of information:
See the three file names in the image at the left. The letters after the dot in the file name is the file extension. It tells the computer which program to use to open that file. Extensions can also give you important information if you are familiar with them. (Note that school computers often won't show the file extension. You will see extensions when you save files and you'll see them on files you find online.)
There are probably thousands of file extensions, but common ones are listed below. If you pay attention to the type of files the programs use that you work with most, you will learn new ones as you need them.
If you are trying to memorize any of these, the extension and brief text that follows is probably sufficient. When you work with them enough you'll soon learn the other details that are included.
Here are some essential extensions everyone should be familiar with:
- .doc or .docx - A document file for Microsoft Word - The .docx is for versions 2007 and later.
- .ppt or .pptx - A presentation file for Microsoft PowerPoint - The .pptx is for versions 2007 and later.
- .mp3 - An audio file that many programs will open or play - It is a popular format for music files because it is small, but still has a good sound quality.
- .jpg - An image file - Many cameras will take pictures in this format and most websites use it to display images. It is popular because the pictures look good, but the files are small enough to load quickly online.
- .pdf - A document file - It is great for sharing online because any device will display it. Almost anyone can open it with many readers. Adobe Reader is most common. Most people won't be able to edit the document.
- .txt - A file with plain text - These files are usually very small and you can open them with Notepad or any other word processor. They don't contain formatting information like a Word document would.
- .exe - A program file or "executable" file - This is the type of file that runs something when you open it. It usually would install something on your computer. Viruses are often .exe files, so you should not run an .exe file if you don't know where it came from or if the source is not trustworthy.
- .gif, .tif, .bmp - Image formats - Most graphics programs can open these or create files in these formats.
- .htm or .html - A webpage file - There are actually many different webpage extensions, but this is probably most common. Your default browser will be the program that opens this type of file.
These extensions are also important, but you might not encounter them until you do more advanced work with digital media:
- .mp4, .mov, .mpg - Compressed video files - There are many formats for compressed video like this, but these are some common ones. These files generally will play on computers and devices like an iPad.
- .wav - An audio file - It has very good sound quality, but it is usually significantly larger than an .mp3 file. Sometimes you might work with .wav files to create an audio file, but in the end you will convert to .mp3 so it can be quickly downloaded online.
- .wmv - A video format associated with Windows programs - This is a good video format, but it might only play on Windows based computers. Movie Maker can create videos of these types and Windows Media Player will play them.
- .avi - A video format - These videos look good, but they are usually not compressed much. That means the files can be extremely large.
- .xls or .xlsx - A spreadsheet file for Microsoft Excel - The .xlsx is for versions 2007 and later.
- .csv - A form of a text file that contains information for a spreadsheet - Instead of being in a table, the values are separated by commas. Many programs that store information (like names, addresses, phone numbers, etc.) will import the data from a .csv file.
- .png - This is a high quality image format - Because it is not compressed (as a .jpg is), the files are large. It makes a good quality for graphic design work.
And here are two formats you might need to recognize when creating projects at school:
- .aup - An Audacity project file - This is an audio project created in Audacity. Remember to export your project as .mp3 or .wav when you are done, since most people who will play your file will not use Audacity.
- .xcf - A file for the GIMP image editing program - You should save GIMP projects in this format as you work on them with that program, but when you are done you will usually want to export them as .jpg or .png.
Some other important pieces of information:
- Zamzar.com is a useful site for converting files from one format to another.
- Not all files can be converted to all other types, but many times you can convert. Sometimes you have to if you want to use a particular program. This is especially true when working with audio and video programs.
- If you can't recognize a file and nothing on your computer will open it, type it in Google with search terms such as "program that opens...". For example, you could type "program that opens .odt file". That will usually give you a clue as to what type of file you are looking at.
- Just because a program gets associated with an extension on your computer, it doesn't mean that program will open the file. Sometimes a change is made on a computer and suddenly Word will try to open .pdf files, for example. It won't work! For directions on how to reset the associations for file extensions (types) see Microsoft's support page here.