WP HTML5 Outliner
Adds an HTML 5 outline plus a heading-level outline to the WordPress Toolbar.
Consider an alternative
WP HTML5 Outliner shows warning signs in 2026 — compare the alternatives below before installing. It runs on 10+ sites and was last updated 7 years ago, and scores 23/100 on our health check.
- Small user base (10+ active installs)
- Very few reviews so far
- No update in 6 years
- Only tested up to WordPress 5.3 (latest is 7.1)
How does it stack up?
Side-by-side on installs, updates, ratings & support
Daily downloads
Download spikes usually follow a new release — each site that auto-updates counts as a download.
Rankings
Where WP HTML5 Outliner stands todayWordPress.org search rankings
Live position in the plugin search, top 100| Keyword | Position |
|---|---|
| accessibility | >100 |
| HTML5 | >100 |
| outline | >100 |
Version adoption
Share of active sites per release.
About WP HTML5 Outliner
From the official readme · v1.3.0Description
WP HTML5 Outliner (WPH5O) adds an HTML 5 outline plus a heading-level outline to the WordPress Toolbar.
Features
- Matches the outlines provided by the W3C Markup Validation Service. Caveat: In an HTML 5 outline, the W3C validator may hide some of the headings in an
<hgroup>if any of them are empty. WPH5O will not. This difference is presentational, not structural. - Adds an ‘Outline’ node to the Toolbar. Outlines are displayed in a dropdown box, with the option to view them in a new browser window.
- Runs only on pages or posts the user can edit. Administrators can view outlines for any page or post. Administration Screens are not outlined.
Changelog
Finalized support for internationalization.
1.3.0
- Change text domain to plugin slug.
- Add i18n support to JS files.
- Edit readme section titled “Why do these outlines matter?”.
1.2.0
- Add function to load plugin’s text domain.
- Ensure ‘No outline was created’ message replaces heading-level outline if source has no headings.
1.1.0
- Fix notices for empty headings in an hgroup element that also contains non-heading elements.
- Shorten Toolbar node title to “Outline”.
1.0.0
- Release the plugin!
Screenshots
For developers
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Best WP HTML5 Outliner alternatives
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FAQ
WP HTML5 Outliner: quick answers
Straight answers, pulled from live WordPress.org data.
Live data from WordPress.org · checked Oct 10, 2026
Is WP HTML5 Outliner free?
Yes. WP HTML5 Outliner is free to download and use from the official WordPress.org plugin directory.
Is WP HTML5 Outliner safe to use in 2026?
WP HTML5 Outliner shows warning signs in 2026 — compare the alternatives below before installing. It runs on 10+ sites and was last updated 7 years ago, and scores 23/100 on our health check.
How many websites use WP HTML5 Outliner?
WP HTML5 Outliner is active on 10+ WordPress websites and has been downloaded 1,837 times since it launched in November 2018. It was downloaded 72 times in the last 30 days.
Does WP HTML5 Outliner work with WordPress 7.1?
WP HTML5 Outliner is officially tested up to WordPress 5.3.26, while the latest release is 7.1.3. It may still work, but try it on a staging site first.
What PHP version does WP HTML5 Outliner need?
WP HTML5 Outliner requires PHP 5.4.5 or higher. Most hosts run PHP 8.x today, so it works on any modern WordPress hosting.
When was WP HTML5 Outliner last updated?
The latest version, 1.3.0, was released on January 27, 2020 (7 years ago).
Who makes WP HTML5 Outliner?
WP HTML5 Outliner is developed and maintained by rsborn.
What are the best alternatives to WP HTML5 Outliner?
The most popular alternatives to WP HTML5 Outliner are Web Accessibility (formally… (500K+ installs), Auto Image Attributes From… (100K+ installs) and Accessibility by UserWay (80K+ installs).
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