Is a file extension the same as a file type?

Not exactly. The extension is the part of the name after the last dot and is just a hint to the operating system. The true file type is determined by the file's actual contents, which is why renaming an extension does not convert the file.

What is the difference between .jpg and .png?

JPG uses lossy compression that is ideal for photographs and small file sizes but discards some detail. PNG uses lossless compression, supports transparency, and is better for logos, screenshots and graphics with sharp edges.

Is anything I search sent to a server?

No. The full list and the search both run entirely in your browser — nothing you type is uploaded anywhere.

File Extensions Reference

Common file extensions and what they mean — searchable.

File extensions — searchable reference

A grouped, searchable list of common file extensions and what each one means: documents like .pdf and .docx, images like .png and .webp, audio and video like .mp3 and .mp4, archives like .zip and .tar.gz, plus code and system files — each with a plain-English description.

Search by extension or description to find the right format instantly. Everything runs in your browser; nothing is uploaded.