Software & Apps File Types 125 125 people found this article helpful What Is an HTM or HTML File? How to open, edit, & convert HTM and HTML files By Tim Fisher General Manager, VP, Lifewire.com Tim Fisher has 30+ years' professional technology support experience. He writes troubleshooting content and is the General Manager of Lifewire. our editorial process Facebook Twitter LinkedIn Tim Fisher Updated November 09, 2019 File Types Design Cryptocurrency MS Office Windows Linux Google Drive Apps File Types Backup & Utilities View More Tweet Share Email A file with the HTM or HTML file extension is a Hypertext Markup Language file and is the standard web page file type on the internet. Since HTM files are text-only files, they just contain text (like what you're reading now), as well as text references to other external files (like the image in this article). HTM and HTML files can also reference other files like video, CSS, or JS files. tumsasedgars / Getty Images How to Open an HTM or HTML File Any web browser, like Internet Explorer, Firefox, Chrome, Opera, etc., will open and properly display HTM and HTML files. In other words, opening one of these files in a browser will "decode" what the HTM or HTML file is describing and display the content correctly. Many programs exist that are designed to make editing and creating HTM/HTML files easy. Some notable free HTML editors include Eclipse, Komodo Edit, and Bluefish. Another popular HTM/HTML editor with lots of advanced features is Adobe Dreamweaver, although it's not free to use. While they're not nearly as rich in features as a dedicated HTM editor, you could just use a simple notepad program to make changes to an HTM or HTML file, like Windows Notepad. However, we recommend using a text editor with more features that are built for a task like this. Here's an example of a very simple HTML page viewed as text: <!DOCTYPE html><html><head><title>This Is Where the Title Goes</title></head><body><h1>Here's One Heading</h1><p>A paragraph can be written here.</p></body></html> As you can see here, this text version of an HTML file is "converted" into a real (albeit stripped down) web page the moment a web browser renders the information. How to Convert HTML & HTM Files HTM files are structured a certain way and have very specific syntax (rules) in order for the code and text within it to display properly when opened in a browser. Because of that, converting an HTM or HTML file to another format probably isn't something you want to do because you'd likely lose any functionality on the page. On the other hand, if all you want to do is convert an HTM or HTML file to another format for easy viewings, like to an image or a PDF, this could be smart and is very doable. This is sometimes a good option over printing it off. In Chrome, you can choose Save as PDF from the print options to convert the page in the window to PDF. Also for Chrome is an extension called Full Page Screen Capture that converts any open HTM or HTML file in the Chrome browser to a PNG file. Other browsers have similar features like Firefox's Save as PDF and PdfIt add-on. You could also use a website dedicated to HTM/HTML to file conversions, like iWeb2Shot, Convert Webpage, or Web-capture. A free file converter can be used to convert an HTM or HTML file that you have saved to your computer. FileZigZag is one free document converter website that converts HTM to RTF, EPS, CSV, PDF and lots of other formats. It's important to realize that you can not convert an HTM/HTML file to anything other than a text file format. For example, an HTML file can never be converted to an MP3 audio file. It may seem like it's possible if you're trying to download an MP3 from a web page, but that's not the correct route to go. HTM vs. HTML Aside from the letter 'L' of course... The short answer: there is none. The long answer: there is none... but be careful to only use one or the other. Back in the MS-DOS days, file extensions were restricted to three characters. In the relatively short period of time when web pages were being created as well as MS-DOS dominion of the universe, HTM ruled since HTML wasn't an option. Today, pages that end in either HTM or HTML are completely acceptable. Just make sure for consistency sake you use one or the other, not both, throughout your website. Additionally, the server that hosts your web pages may require your index page ends in one or the other file extension. In other words, you may need to use index.html or index.htm. Check with your hosting provider or web server software maker if you're not sure. Still Can't Open Your File? HTML and HTM files should be fairly easy to open since they are just text files that any web browser can view. If your file isn't opening with any of the suggested programs from above, there's a good chance that you're not really dealing with a Hypertext Markup Language file. Some file formats use file extensions that closely resemble HTML/HTM but aren't actually in the same format. One prime example is the HTMLZ file extension used for Zipped HTML eBook files. There are HTML files inside the HTMLZ file but the format of the whole package is ZIP, which won't open in a web browser or with a text editor. In this example, you'd need a specific HTMLZ file viewer like Calibre. Or, since this file format is actually an archive, you could open it with a file decompressor like 7-Zip, after which you could open any individual HTML files with a web browser or any of the other HTML viewers/editors mentioned above.