How can I include HTML like <sup> in a WordPress Post Title?

Other Questions Wordpress
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I’m facing a challenge with my WordPress site where I have custom post types for products. I need to have the registered trademark symbol (®) in superscript format in the titles, but when I add <sup>®</sup> to the title, it shows up as plain text.

Here’s what I’ve tried: I’m using a self-hosted WordPress site with the Astra theme and Beaver Builder. I’ve attempted to use different methods, including writing a function to replace the trademark symbols with their superscripted versions in single post titles, but this doesn’t work on the archive pages where the HTML appears instead of being rendered as superscript.

Is there a way to achieve this across all types of pages or a solution that involves adjusting templates?

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WordPress strips HTML from titles using wp_strip_all_tags() - that’s why your superscript tags show up as plain text. I ran into this same issue on a legal site that needed trademark symbols everywhere. Here’s what worked: Store titles with placeholders like “ProductName[TM]” in your database. Then add a filter that uses str_replace() to swap those placeholders for actual HTML when displaying. Hook into both single_post_title and get_the_archive_title filters to cover all cases. This way your stored titles stay clean for SEO, but users see the formatted version. Just test it with your theme since some themes mess with title functions in weird ways.

3

Just dealt with this on a manufacturing site with chemical product names. WordPress strips HTML from titles through multiple sanitization layers, so HTML tags don’t stick consistently.

Here’s what worked: I used wptexturize with a custom shortcode approach. Instead of fighting WordPress’s sanitization, I created a simple [sup] shortcode that gets processed during rendering. Then I hooked into the the_title filter to run do_shortcode() on titles before they display.

This skips the HTML stripping but keeps things secure since shortcodes process after sanitization. Works everywhere - archive pages, breadcrumbs, you name it. Plus it’s editor-friendly. Your content team can just type [sup]®[/sup] instead of remembering HTML tags. Just make sure your theme doesn’t double-escape the output.

4

Had the same headache with my theme. Skip the WordPress filters - use CSS pseudo-elements instead. Add a ‘trademark’ class to your title, then use ::after with content: ‘®’ and position: relative; top: -0.5em. Works everywhere and won’t mess with functions.php or SEO.

5

WordPress title sanitization is such a headache when you need formatting. Hit this issue on a client project - they had hundreds of product names with trademark symbols.

WordPress sanitizes titles everywhere, so using filters means updating tons of template files. Plus you’re risking SEO and accessibility problems.

I ended up automating it with Latenode instead. Built a workflow that watches for new posts and updates the frontend display without messing with WordPress core.

The automation grabs post data, finds trademark symbols, and injects proper HTML through a custom endpoint that replaces content when pages load. Works on all page types without touching theme files or creating security holes.

Latenode handles when and where to apply formatting, so archive pages, single posts, and widgets all display right. Way cleaner than fighting WordPress filters.

6

The Problem:

You’re encountering an issue where WordPress strips HTML tags from post titles, preventing the display of superscripted registered trademark symbols (®). You’ve tried adding <sup>®</sup> directly to the title, but it renders as plain text across both single post views and archive pages. You’re looking for a solution that works consistently across all page types without requiring extensive template modifications or sacrificing SEO.

:thinking: Understanding the “Why” (The Root Cause):

WordPress employs various sanitization functions, such as wp_strip_all_tags(), to prevent cross-site scripting (XSS) vulnerabilities. These functions remove HTML tags from post titles to ensure security. Directly embedding HTML within the title text conflicts with these security measures, causing the tags to be stripped. Simply applying filters to the_title might not be sufficient for complete coverage as different areas of your theme might use various title-fetching mechanisms.

:gear: Step-by-Step Guide:

Step 1: Utilize the wp_title and the_title Filters with wp_kses:

This approach allows you to whitelist specific HTML tags within your post titles, enabling the display of superscripted text while maintaining WordPress’s security protocols.

  1. Add a Custom Function to your functions.php file: This function uses wp_kses to whitelist only the <sup> and </sup> tags.

    function allow_sup_sub_in_title( $title ) {
    $allowed_html = array( 'sup' => array() );
    return wp_kses( $title, $allowed_html );
}

  2. Hook the function into the wp_title filter: This ensures that the allowed HTML tags are preserved before the title is displayed in various areas of your theme.

    add_filter( 'wp_title', 'allow_sup_sub_in_title' );

  3. Hook the function into the the_title filter (optional but recommended): While the wp_title filter often works across your theme, using the the_title filter provides complete control over how the title is displayed.

    add_filter( 'the_title', 'allow_sup_sub_in_title' );

Step 2: Test Thoroughly and Adjust Theme Outputs:

It’s crucial to test this solution extensively across your theme. Some themes might not consistently use the_title() for displaying titles. You might need to locate instances where get_the_title() is used (often within header.php or other template files) and modify them to leverage the filtered output by changing <?php the_title(); ?> to <?php echo get_the_title(); ?>. This change ensures that the custom filter is applied across all title implementations within your theme.

Step 3: Verify your Theme’s Title Handling

Some themes apply additional sanitization or escaping to titles. Review your theme’s code, particularly functions used for displaying titles within loops or custom template files. If you discover additional escaping or sanitization, work with your theme developer to modify these functions so they only process allowed HTML tags before displaying them.

:mag: Common Pitfalls & What to Check Next:

  • Incomplete Theme Coverage: Ensure the filter is applied to all instances where titles are displayed in your theme, not just the_title().
  • Conflicting Plugins: Plugins that modify title display behavior might interfere with this solution. Deactivate other plugins temporarily to rule this out.
  • SEO Plugin Compatibility: Some SEO plugins modify titles for meta descriptions. Ensure compatibility by carefully reviewing your SEO plugin’s settings or documentation.
  • Caching: Flush your caching plugins after implementing the code changes.

:speech_balloon: Still running into issues? Share your (sanitized) config files, the exact command you ran, and any other relevant details. The community is here to help!

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