What is a KEY file?
The .KEY file extension has three common uses. The most frequent use is for Apple Keynote presentations. These files store presentation slides, images, text, and transition data. Because they use standard ZIP compression, you can sometimes rename the extension to .ZIP to inspect the internal media contents.
However, the .KEY extension is also heavily used for security files. It often stores cryptographic private or public keys for secure web traffic, SSH access, or encryption software like GnuPG. Finally, many software companies, such as WinRAR and Avira, use .KEY files to store software license registration codes.
How to open KEY files?
Because .KEY files serve different purposes, opening them depends on their actual format. You can open presentation files using Apple Keynote on macOS or iOS. For cryptographic keys, system administrators usually load them into server software, terminal tools like PuTTYgen, or SSH clients. License files are typically placed in a specific software installation folder.
If you are unsure what kind of .KEY file you have, viewer.online/key analyzes .KEY files to identify their exact format and creator software. It shows which programs can open the file and usually previews it directly in your web browser.
File Conversion
You might need to convert your .KEY presentation to a more universal format to share it with Windows users. You can easily convert these files to sensible target formats on convert.guru. The most common target formats are .PPTX for Microsoft PowerPoint and .PDF for easy reading. Cryptographic and license .KEY files contain plain text or encoded security data and usually do not require conversion.
Summary
viewer.online/key directly opens and previews .KEY files in the browser, eliminating the need to install software or troubleshoot compatibility issues. This allows you to quickly determine if your file is a presentation, a security key, or a software license.