Semantic Linkbacks for WebMentions, Trackbacks and Pingbacks

3.5.1 2017-10-03 17:38 UTC


Contributors: pfefferle, dshanske
Donate link:
Tags: webmention, pingback, trackback, linkback, microformats, comments, indieweb
Requires at least: 4.8.2
Requires PHP: 5.3
Tested up to: 4.8.2
Stable tag: 3.5.1
License: MIT
License URI:

Richer Comments and Linkbacks for WordPress!


Generates richer WordPress comments from linkbacks such as Webmention or classic linkback protocols like Trackback or Pingback.

The limited display for trackbacks and linkbacks is replaced by a clean full sentence, such as "Bob mentioned this article on" If Bob's site uses markup that the plugin can interpret, it may add his profile picture or other parts of his page to display as a full comment.

Semantic Linkbacks uses Microformats 2 to get information about the linked post and it is highly extensible to also add support for other forms of markup.

Frequently Asked Questions

Do I need to mark up my site?

Most modern WordPress themes support the older Microformats standard, which means the plugin should be able to get basic information from to enhance linkbacks. The plugin is most useful with webmention support(separate plugin) and sites/themes that support Microformats 2.

Why Webmentions?

Webmention is a modern reimplementation of Pingback and is now a W3C Recommendation.

What about the semantic "comment" types?

The IndieWeb community defines several types of feedback:

How do I extend this plugin?

See Extensions

How do I add this into my plugin?

The plugin will automatically enhance webmentions, trackbacks, and pingbacks with an avatar and additional context. It will also automatically add a facepile instead of individual comments, but this feature can either be turned off by an aware theme or under Discussion in your Settings.

Who made the logos?

The Webmention and Pingback logos are made by Aaron Parecki and the Microformats logo is made by Dan Cederholm


Project actively developed on Github at pfefferle/wordpress-semantic-linkbacks. Please file support issues there.


  • Bugfix release


  • Add Facepile code
  • Add setting to disable automatic facepile include
  • Add filter to allow themes to disable the setting and the feature if they facepile themselves
  • Add PHP requirement to readme file


  • Abstract out linkback retrieval functions to allow for easier changes in future
  • Fix retrieval issue
  • Remove merge and compatibility function creating double slashing due update in 4.7.1
  • Replace blacklist for properties with whitelist for select properties
  • Update avatar function to not override if user_id is set on assumption local overrides remote


  • Fix Tests and Error in Authorship
  • Update Parser
  • Switch to looser restrictions if WP_DEBUG is enabled and stricter ones otherwise
  • Enhance Author Properties to allow for retrieving remote h-card
  • Store mf2 properties
  • Store location in WordPress Geodata
  • Use rel-syndication if not u-syndication
  • Support new webmention source meta key



  • Due to changes in WordPress 4.4 through 4.7 and version 3.0.0 of the Webmentions plugin this plugin can act on the retrieved remote source rather than rerequesting this information.
  • Major enhancement work is done in preprocessing now rather than post-processing
  • Refactoring
  • Render full mention content if short enough. Introduce MAX_INLINE_MENTION_LENGTH which defaults to 300 characters to implement same.
  • Fix text domain


  • updated hooks/filters


  • changed hook from <linkback>_post to comment_post (thanks to @dshanske)
  • used the WordPress Coding Standard
  • small code improvements


  • I18n support
  • German translation
  • some small changes and bugfixes


  • quick fix to prevent crash if Mf2 lib is used by a second plugin


  • added counter functions for comments by type (props to David Shanske)
  • some bugfixes


  • some small tweaks
  • added custom comment classes based on the linkback-type (props to David Shanske for the idea)


  • added support for threaded comments


  • fixed bug in comments section


  • nicer integration with trackbacks, linkbacks and webmentions
  • cleanup


  • "via" links for indieweb "reply"s (thanks to @snarfed for the idea)
  • simplified output for all other indieweb "comment" types
  • better parser (thanks to voxpelly for his test-pinger)
  • now ready to use in a bundle


  • initial release

Thanks to


  1. Upload the webmention-folder to the /wp-content/plugins/ directory
  2. Activate the plugin through the Plugins menu in WordPress
  3. ...and that's it :)