.HTM File Extension
File TypeHypertext Markup Language File
HTML Web page used by Web browsers; contains markup code that is stored a plain text format; used to display and format text and images in a Web browser.
HTM files serve the exact same purpose as .HTML files. The ".htm" extension arose with the use of Microsoft Web development software, such as FrontPage, SharePoint Designer, and Expression Web.
HTM files are much less commonly seen than HTML files.