What is the WHTML file format?
A .whtml file is a document saved by the TinyMCE editor inside daedalOS, an open-source desktop environment that runs in a web browser. The project comes from developer Dustin Brett, and the .whtml suffix is a naming convention it uses rather than a formal standard. In the daedalOS source code the extension is registered as the type WysiwygHtmlDocument.
Despite the unusual extension, the file is ordinary HTML. It is plain UTF-8 text you can read in any editor, and it usually holds a body fragment: headings, paragraphs, lists, links, images, and inline styles created through TinyMCE's what-you-see-is-what-you-get interface. There is no compression, no encryption, and no binary signature. That makes a .whtml file closely related to a standard .html page, just with a different suffix and often without the surrounding <html> and <body> wrapper tags.
Security & safety
RISK: LOWA .whtml file is plain HTML text and cannot run on its own. The only caution is that HTML can contain embedded <script> tags or remote references, so open files from unknown sources in a text editor first rather than rendering them in a browser.
Format details
in a nutshell- Generic WYSIWYG HTML output - Some editors and templates informally use
.whtmlto label WYSIWYG-generated HTML fragments; content is still standard HTML. - Web page template naming - Occasionally seen as an ad-hoc suffix for HTML template or partial files in custom build setups.
Programs that open WHTML files
Windows3 apps
Visual Studio Code
Free Open the .whtml file to read and edit the raw HTML, with syntax highlighting and a live HTML preview via an extension. 
Any web browser (Chrome / Edge / Firefox)
Free Rename the file to .html, then open it in the browser to see the formatted content rendered. 
macOS3 apps
Linux3 apps
daedalOS
Open-source Double-click the .whtml file in the daedalOS file manager to open it in the built-in TinyMCE editor. Technical details
deep spec| Encoding | UTF-8 text |
| Byte order | Not applicable (text); optional UTF-8 BOM |
| Container | None; raw HTML markup fragment |
| Typical size | A few hundred bytes to tens of kilobytes |
| Structure | A `.whtml` file holds the HTML produced by the TinyMCE rich-text editor inside daedalOS. It stores formatted body content (paragraphs, headings, lists, links, images) with inline styles rather than a complete standalone HTML page. There is no requirement for `<html>`, `<head>`, or `<body>` wrapper tags. |
| Platforms | Web browser (daedalOS), Windows, macOS, Linux |
| Notes | The extension is a naming convention used by daedalOS, Dustin Brett's browser-based desktop environment. In the daedalOS codebase the extension is mapped to the type WysiwygHtmlDocument, opened by the built-in TinyMCE app with generic text editors as a fallback. It is not a formal, registered standard, and mainstream browsers do not associate `.whtml` with HTML rendering by default. |
| Released | 2021 |
| Specification | github.com |
WHTML conversions
Community Q&A
asked by usersNo questions yet - be the first to ask about WHTML files.
Frequently asked questions
What program opens a WHTML file?
.html.Is a WHTML file the same as an HTML file?
.whtml suffix is a naming convention used by daedalOS for documents saved from its TinyMCE app. Rename it to .html and it behaves like a normal web page.Why won't my browser open a .whtml file directly?
.whtml extension with HTML by default, so they may offer to download it instead of rendering it. Rename the file to .html to view the formatted content.How do I convert a WHTML file to PDF?
.html, open it in a browser, then use Print and choose Save as PDF. TinyMCE within daedalOS can also export the open document.
