<bb>
The <bb> element (browser button) was proposed as part of an early HTML5 draft to represent a user agent command that the user could invoke. It was intended to allow web pages to provide browser functionality buttons, such as "Add to Favorites" or "Print Page" commands. However, this element was never implemented by any browser and was removed from the HTML5 specification.
This page was last updated on 2025-11-17
Deprecation Warning
DO NOT USE THIS ELEMENT. The <bb> element was never implemented in any browser and has been removed from all HTML specifications. It exists only in historical documentation of early HTML5 drafts.
Any code using this element will be treated as an unknown element by browsers, and it will have no effect on the page functionality. It will be rendered as an inline element with no special behavior.
History
The <bb> element appeared in very early working drafts of HTML5 (around 2007-2008) as part of an attempt to standardize browser command interfaces. The idea was to:
- Allow web pages to trigger browser-specific commands
- Provide a standardized way to add bookmarks, print pages, or access browser features
- Create a semantic element for user agent interactions
The element was quickly removed because:
- Security concerns about pages controlling browser behavior
- Lack of interest from browser vendors
- Inconsistent behavior across different browsers would be inevitable
- JavaScript APIs already provided similar functionality with more control
Original Proposed Syntax
The proposed syntax was:
<bb type="command-name">Label</bb>
Proposed attributes included:
- type — The type of browser command (e.g., "makeapp", "addtofavorites")
Example of what the syntax might have looked like:
<!-- This code does NOT work -->
<bb type="addtofavorites">Bookmark this page</bb>
Modern Alternatives
Instead of the never-implemented <bb> element, use these approaches:
For Print Functionality
<button onclick="window.print()">Print this page</button>
For Sharing/Bookmarking
<button onclick="navigator.share({title: 'Page Title', url: location.href})">
Share this page
</button>
For Custom Actions
<button type="button" class="action-btn">Custom Action</button>
<script>
document.querySelector('.action-btn').addEventListener('click', function() {
// Your custom functionality
});
</script>
These JavaScript-based solutions provide the intended functionality while maintaining security and cross-browser compatibility.
