Mime Types Query Tool is an online tool that allows you to find out the MIME type of a file based on its extension. MIME types are standardized labels that indicate the nature and format of a document, file, or assortment of bytes. They are used by browsers and servers to determine how to handle different kinds of data.

To use this Mime Types Query Tool, you can either select the file extension (such as .html, .jpg, .pdf, etc.) that you want to query. The tool will then display the corresponding MIME type (such as text/html, image/jpeg, application/pdf, etc.) and some additional information about the file format, such as its description, typical usage, and related links.