Generate Random File Extension

Generate fake but realistic file extensions to use in software testing, user interface demos, mock data sets, or development environments where file-type variety is essential.

Free Random File Extension Generator

This tool produces extensions such as jpeg, scs, xsl, and many more - all designed to resemble real-world formats used across documents, images, code, and media files.

You can generate up to 1000 random file extensions in a single click, and export the results as CSV, Excel, or HTML - or simply copy them to your clipboard for immediate use.

Each extension is randomly selected from a diverse list of known types to give your datasets a natural and believable distribution of file formats.

These extensions are useful for file upload simulations, download link demos, or placeholder entries in sample databases, helping developers and designers create more authentic experiences.

The tool is completely free to use and requires no sign-up - just click, generate, and get realistic file extensions for any test or mockup.