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FAQ
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Everything you need to know about file extensions
A file extension is the suffix at the end of a file name (such as .pdf or .jpg) that identifies the file type and determines which programs can open it.
To open an unknown file, first identify its file extension. Once identified, you can use compatible software or convert the file to a supported format if necessary.
On Windows and macOS, file extensions are generally not case sensitive. However, on many Linux systems and web servers, file extensions can be case sensitive.
If a file won't open, make sure you are using the correct program for its file type. Updating the software, checking for file corruption, or converting the file may help.
Changing a file extension does not convert the file format and may cause the file to stop working. To properly change formats, use a file conversion tool designed for that file type.