Your one-stop guide to understanding every file format. Find technical details, compatibility info, and step-by-step instructions on how to open any file type.
File extensions are short identifiers that tell operating systems like Windows and macOS which application is responsible for handling a file. Without these identifiers, your computer wouldn't know if a file is an image, a document, or an executable program.
Many formats like .PDF, .JPG, and .MP4 are cross-platform, meaning they work flawlessly on both Windows and Mac. Others, like .DMG or .EXE, are platform-specific. Our encyclopedia helps you identify whether a file is compatible with your current device.
A common issue users face is having a file but not the right software to open it. We provide curated lists of the best software for each extension, focusing on both professional tools (like Adobe Creative Cloud) and free open-source alternatives (like VLC or LibreOffice).