Theme Check — Full WordPress Theme Error Checking in 15 Minutes

Has your WordPress site suddenly stopped working? White screen, critical error, or just strange display? Most often the problem lies in the theme. One unfixed error in your theme can cost you traffic, search rankings, and even reputation. But here's the good news: Theme Check — the official plugin from WordPress.org — lets you automatically check your theme for all types of errors in just a few minutes.

In this article, you'll learn how Theme Check works, what errors it finds, how to fix them, and why regular checking is a must‑do ritual for every WordPress site owner.

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What is Theme Check and why do you need it

Theme Check is a free WordPress plugin that automates checking themes against the standards and requirements of the official WordPress.org directory. It scans all your theme files, analyzes the code, and provides a detailed report with errors, warnings, and recommendations.

In essence, Theme Check is the same tool used by WordPress.org reviewers when moderating new themes. If your theme passes the check without errors — it meets high standards of quality, security, and performance.

The tool will be useful for:

• Developers — for quick debugging and preparing themes for publication
• Site owners — for checking purchased or downloaded templates before installation
• Freelancers and agencies — for quality control of solutions delivered to clients

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Great plugin and support! It works well!

What errors does Theme Check find: full list of checks

Theme Check performs dozens of checks, divided into several categories. Here are the main ones:

Required checks

These checks are critical. If a theme doesn't pass them — it will not be accepted into the official directory.

• Presence of wp_head() and wp_footer() in templates
• Support for add_theme_support('title-tag')
• Support for add_theme_support('automatic-feed-links')
• Presence of required files: index.php, style.css, functions.php
• Correct registration of widget areas and menus

Security checks

Theme Check strictly controls potentially dangerous constructs:

• Prohibition of eval(), base64_decode(), system() and other dangerous functions
• Prohibition of changing PHP server settings
• Prohibition of Google advertising code and other third‑party inserts

Code quality checks

• Using get_template_directory() instead of the deprecated constant TEMPLATEPATH
• Presence of the $content_width variable for proper content display
• Correct handling of translations (i18n)
• No short PHP tags < ?

WordPress standards checks

• Presence of DOCTYPE, language_attributes, charset
• Use of body_class(), post_class(), comment_form()
• Proper use of home_url() and site_url()

Deprecated code checks

The plugin finds functions that have been declared deprecated in new versions of WordPress and recommends replacing them.

File structure checks

Theme Check looks for the presence of service folders .git, .svn and the existence of the readme.txt file.

In total, the plugin performs more than 50 different checks, covering virtually all aspects of a quality theme.

How to install and run Theme Check

Installing the plugin takes no more than a minute:

1. Go to the WordPress admin panel: Plugins → Add New
2. In the search box, type Theme Check
3. Find the plugin from WordPress.org and click "Install", then "Activate"

After activation, go to Tools → Theme Check. You will see a list of all installed themes. Select the one you need and click "Check it!".

The results are displayed as a color‑coded report:

• Red — critical error (Required). The theme must be fixed.
• Orange — warning (Warning). It is recommended to fix, but does not block publication.
• Green — recommendation (Info). It is advisable to take into account.

Comparison of Theme Check with alternatives

There are several tools on the market for checking themes. We compared the most popular ones.

Conclusion: Theme Check is the best choice for most tasks due to its official status, completeness of checks, and ease of use. For checking child themes, you can additionally use ThemeCheck.org. For commercial themes on ThemeForest — Envato Theme Check.

User reviews and real‑world experience

Theme Check is one of the most popular tools for WordPress developers. Here is what users say:

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I heard good things about this plugin until I used it. It says my theme name and ...

Some users note that the plugin can produce false positives, especially on child themes. For example, if a child theme inherits functions from the parent, Theme Check may not find them in the child theme's files and throw an error.

There are also complaints about high memory consumption when checking large themes. If you get a white screen during the check, increase the PHP memory limit in the wp-config.php file:

define('WP_MEMORY_LIMIT', '256M');

Despite these nuances, the vast majority of developers consider Theme Check an indispensable tool.

Frequently Asked Questions (FAQ)

add_theme_support('title-tag');

wp theme-check

How to fix the most common errors

Here are step‑by‑step instructions for the five most common errors found by Theme Check:

1. Missing wp_head() and wp_footer()

Error: "wp_head() not found" / "wp_footer() not found"

Solution: Open header.php and add < ?php wp_head(); ? > right before the closing < /head> tag. In footer.php, add < ?php wp_footer(); ? > before the closing < /body> tag.

2. No add_theme_support('title-tag')

Error: "No reference to add_theme_support('title-tag')"

Solution: Add to functions.php:

add_theme_support('title-tag');

3. No add_theme_support('automatic-feed-links')

Error: "Could not find add_theme_support('automatic-feed-links')"

Solution: Add to functions.php:

add_theme_support('automatic-feed-links');

4. Using TEMPLATEPATH instead of get_template_directory()

Error: "Use get_template_directory() rather than TEMPLATEPATH"

Solution: Replace all occurrences of TEMPLATEPATH with get_template_directory() in your code.

5. Missing $content_width

Error: "$content_width not defined"

Solution: Add to functions.php after the theme declaration:

if (!isset($content_width)) {
    $content_width = 800; // Set your content width
}

Benefits of regular checking

Regular use of Theme Check provides many advantages:

• Security: Identifies vulnerabilities before they can be exploited by attackers
• Performance: Optimizes code, speeding up page loading
• Compatibility: Ensures work with new versions of WordPress
• User trust: A quality theme means satisfied visitors
• Time savings: Automation replaces hours of manual auditing

It is especially important to check your theme before every WordPress update. New core versions may contain changes that make deprecated code non‑functional.

Conclusion

Theme Check is a must‑have tool for everyone who works with WordPress. Whether you are a developer, site owner, or freelancer — regular theme checks will help you avoid critical errors, preserve traffic and reputation.

We have covered all aspects of the plugin: from installation to fixing the most common errors. Now you know how to check any template in 15 minutes and make it secure and reliable.

Don't put off checking until later. One error in your theme can cost you thousands of visitors.

Use Theme Check today and forget about sudden site crashes. Your visitors and search engines will thank you.