Checklist: 15 Things You Must Do Before Changing WordPress Themes

Table of Contents#

1. Backup Your Entire Website
2. Document Current Customizations
3. Export Widgets and Menus
4. Audit Theme-Specific Shortcodes
5. Evaluate Plugin Compatibility
6. Test Responsive Design
7. Verify SEO Elements
8. Check Permalink Structure
9. Review User Roles and Permissions
10. Set Up a Staging Environment
11. Test Performance Metrics
12. Ensure Legal Compliance
13. Conduct a Content Review
14. Gather Feedback
15. Prepare for Post-Switch Checks

1. Backup Your Entire Website#

Before making any major change to your site—including switching themes—backing up your website is non-negotiable. A backup acts as a safety net if something goes wrong (e.g., data loss, broken code, or a non-functional theme).

What to Backup:#

• Database: Stores all your content (posts, pages, comments, user data, settings).
• Files: Includes your theme files, plugins, media uploads, and core WordPress files.

How to Backup:#

Option 1: Use a Backup Plugin (Recommended for Beginners)#

Plugins like UpdraftPlus, BackupBuddy, or VaultPress automate backups. For example, with UpdraftPlus:

1. Install and activate the plugin.
2. Go to Settings > UpdraftPlus Backups.
3. Click “Backup Now” and select “Database” and “Files.”
4. Store the backup offsite (e.g., Google Drive, Dropbox, or UpdraftPlus Cloud) for security.

Option 2: Manual Backup (For Advanced Users)#

• Database: Use phpMyAdmin (via your hosting cPanel) to export your database as a SQL file.
• Files: Connect via FTP (e.g., FileZilla) or cPanel File Manager, then zip and download the /wp-content/ folder (themes, plugins, uploads) and core files (e.g., wp-config.php).

Pro Tip:#

Test your backup by restoring it to a local staging site (e.g., using XAMPP or Local by Flywheel) to ensure it works.

2. Document Current Customizations#

Most WordPress sites have customizations that live in the current theme—e.g., custom CSS, PHP snippets, or template edits. If you switch themes without documenting these, they’ll be lost.

What to Document:#

• Custom CSS: Check the WordPress Customizer (Appearance > Customize > Additional CSS), theme files (style.css), or plugins like Simple Custom CSS & JS.
• PHP/HTML Edits: Look for changes in functions.php, header.php, footer.php, or custom templates (e.g., single.php for blog posts).
• Child Theme Edits: If you use a child theme, document all files in /wp-content/themes/child-theme/—these override the parent theme.
• Custom Post Types (CPTs): If your theme registers CPTs (e.g., “Portfolio” or “Testimonials”), note their slugs and custom fields.

How to Document:#

• Create a spreadsheet or text file listing:
  • File path (e.g., /wp-content/themes/parent-theme/functions.php).
  • Snippet of code (e.g., add_action('wp_head', 'my_custom_meta_tag');).
  • Purpose (e.g., “Adds meta tag for Google Analytics”).
• Use tools like WP Code (formerly Insert Headers and Footers) to export custom code snippets.

3. Export Widgets and Menus#

Widgets and navigation menus are often tied to your current theme’s widget areas and menu locations. A new theme may have different widget areas (e.g., “Sidebar” vs. “Right Sidebar”) or menu locations (e.g., “Primary Menu” vs. “Header Menu”), causing widgets to disappear or menus to break.

Export Widgets:#

• Use a plugin like Widget Importer & Exporter:
  1. Install and activate the plugin.
  2. Go to Tools > Widget Settings Import/Export.
  3. Click “Export Widget Settings” to save a JSON file.
• Note which widgets are in which areas (e.g., “Search Widget in Sidebar 1”).

Export Menus:#

• Menus are stored in the database, but you can note their structure:
  1. Go to Appearance > Menus.
  2. For each menu, take screenshots or list items (e.g., “Home > About > Team”).
  3. Note assigned locations (e.g., “Primary Menu” is assigned to “Top Navigation”).

Pro Tip:#

After switching themes, use the same plugin to import widgets. For menus, reassign them to the new theme’s menu locations in Appearance > Menus.

4. Audit Theme-Specific Shortcodes#

Many themes include custom shortcodes (e.g., [theme_cta] for a call-to-action button or [featured_posts] for a post slider). If your new theme doesn’t support these shortcodes, they’ll appear as plain text on your site.

How to Audit:#

1. Identify Shortcodes:
   • Search your content for brackets [] (e.g., in posts, pages, or widget text).
   • Check your theme’s documentation for a list of shortcodes (e.g., “ThemeX Shortcode Reference”).
2. Check New Theme Compatibility:
   • Review the new theme’s documentation to see if it includes equivalent shortcodes.
   • If not, find a plugin to replace them (e.g., Shortcodes Ultimate for generic shortcodes or Elementor for page-building shortcodes).
3. Replace or Migrate:
   • Use a plugin like Better Search Replace to bulk-replace old shortcodes with new ones (e.g., replace [theme_cta] with [su_cta]).

5. Evaluate Plugin Compatibility#

Plugins and themes often work together, but some plugins are theme-dependent (e.g., page builders bundled with themes like Divi or Avada). A new theme may break these plugins or vice versa.

Steps to Check Compatibility:#

1. List Active Plugins: Go to Plugins > Installed Plugins and export the list (use a screenshot or plugin like WP Plugins Export).
2. Identify Critical Plugins: Flag plugins essential to your site (e.g., SEO, security, e-commerce, contact forms).
3. Test Compatibility:
   • On a staging site (see Step 10), deactivate non-essential plugins, then activate the new theme. Reactivate plugins one by one to spot conflicts.
   • Use the Health Check & Troubleshooting plugin (officially recommended by WordPress) to simulate a clean environment and test theme-plugin interactions.

Red Flags:#

• Plugins labeled “[Theme Name] Add-On” (e.g., “Twenty Twenty-Three Companion”). These will likely break with a new theme.
• Plugins that modify theme templates (e.g., Custom Post Type UI may still work, but double-check CPT display).

6. Test Responsive Design#

A theme that looks great on desktop may fail on mobile. With over 50% of web traffic coming from mobile devices, responsive design is critical.

What to Test:#

• Mobile Navigation: Does the menu collapse into a hamburger icon? Are dropdowns usable?
• Content Layout: Are text, images, and buttons properly sized (no horizontal scrolling)?
• Media: Do images resize without distortion? Are videos playable on mobile?
• Touch Elements: Are buttons/links large enough for taps (minimum 44x44px per WCAG guidelines)?

Tools to Test:#

• Chrome DevTools: Right-click > “Inspect,” then click the mobile icon to simulate devices (e.g., iPhone, iPad, Android).
• BrowserStack: Test on real devices and browsers (free tier available for limited testing).
• Responsive Design Checker: Free tools like Responsive Test Tool let you preview on multiple screen sizes.

Pro Tip:#

Prioritize testing on popular devices (e.g., iPhone 15, Samsung Galaxy S23, iPad) and browsers (Chrome, Safari, Firefox).

7. Verify SEO Elements#

A theme change can accidentally disrupt SEO if it alters meta tags, header structure, or structured data. Poor SEO after a theme switch may lead to traffic drops.

What to Verify:#

• Meta Titles/Descriptions: Ensure your SEO plugin (Yoast SEO, Rank Math) still controls these. Check a post’s edit screen to confirm.
• Header Tags (H1-H6): The new theme should use H1 tags for page titles (one per page) and H2-H6 for subheadings. Use the Yoast SEO plugin’s “SEO Analysis” tab to audit.
• Structured Data: Themes often include schema markup (e.g., Article, Organization). Test with Google’s Rich Results Test to ensure it still validates.
• Open Graph/Twitter Cards: Confirm social media previews (title, image, description) work using Facebook Sharing Debugger.

Pro Tip:#

Use Screaming Frog SEO Spider to crawl your staging site before and after the theme switch. Compare H1 counts, meta tags, and broken links.

8. Check Permalink Structure#

Permalinks (e.g., yoursite.com/blog/post-title) are controlled by WordPress, not themes—but switching themes can trigger .htaccess file issues, leading to 404 errors.

How to Check:#

1. Before switching, note your permalink structure: Settings > Permalinks (e.g., “Post name”).
2. After switching themes, revisit Settings > Permalinks and click “Save Changes” (no need to edit). This regenerates the .htaccess file and fixes most permalink issues.

Red Flags:#

• If you see 404 errors after switching, check wp-config.php for define('permalink_structure', '');—remove this line if present.
• For Nginx servers, ensure your nginx.conf file includes rewrite rules for permalinks (ask your host for help).

9. Review User Roles and Permissions#

Some themes add custom user roles (e.g., “Editor” with limited access to theme settings) or modify capabilities (e.g., “Author” can edit widgets). A new theme may reset these roles.

How to Review:#

1. Go to Users > All Users and check role assignments (e.g., “Admin,” “Editor”).
2. Use a plugin like User Role Editor to:
   • List custom roles added by the current theme.
   • Export role settings (e.g., capabilities like edit_theme_options).
3. After switching themes, reapply custom roles using the same plugin.

10. Set Up a Staging Environment#

Testing a new theme on your live site is risky—even small issues (e.g., broken buttons) can frustrate visitors. A staging environment is a clone of your live site where you can test changes safely.

How to Set Up Staging:#

Option 1: Use Your Hosting Provider#

Many hosts (e.g., Bluehost, SiteGround, WP Engine) offer free staging tools:

1. Log into your hosting dashboard (e.g., cPanel, SiteGround Client Area).
2. Find the “Staging” or “Clone Site” option.
3. Select your live site and create a staging clone (e.g., staging.yoursite.com).

Option 2: Use a Plugin#

Plugins like WP Staging or Duplicator let you create staging sites:

1. Install WP Staging, go to WP Staging > Create Staging Site.
2. Name the staging site (e.g., “Staging”), select “Complete Clone,” and click “Start Cloning.”

What to Test on Staging:#

• Activate the new theme and check all customizations (Step 2).
• Test plugins (Step 5), widgets/menus (Step 3), and responsive design (Step 6).
• Audit SEO elements (Step 7) and content (Step 13).

11. Test Performance Metrics#

A beautiful new theme may slow down your site if it’s bloated with unoptimized code, scripts, or fonts. Poor performance hurts user experience and SEO.

What to Test:#

• Page Load Time: Aim for <3 seconds (per Google’s recommendation).
• Page Size: Keep total page weight <3MB (images and scripts are often the culprits).
• Core Web Vitals: Google’s ranking factors:
  • Largest Contentful Paint (LCP): <2.5s.
  • First Input Delay (FID): <100ms.
  • Cumulative Layout Shift (CLS): <0.1.

Tools to Measure Performance:#

• GTmetrix: Provides a performance score (A-F), load time, and optimization tips (e.g., “Optimize images”).
• PageSpeed Insights: Google’s tool that grades Core Web Vitals and suggests fixes.
• WebPageTest: Shows load times across locations and devices (e.g., “San Francisco, Chrome Mobile”).

How to Optimize:#

• If the new theme is slow, use Asset CleanUp to disable unused scripts/styles.
• Compress images with ShortPixel or Smush.
• Enable caching with WP Rocket or LiteSpeed Cache.

12. Ensure Legal Compliance#

Themes control how legal content (e.g., privacy policies, cookie notices) is displayed. A new theme may hide or misformat these, risking legal penalties (e.g., GDPR fines).

What to Check:#

• Privacy Policy: Ensure it’s linked in the footer (common legal requirement).
• Cookie Consent: If your site uses cookies, verify the cookie banner appears (use plugins like Cookie Notice & Compliance for GDPR/CCPA).
• Terms of Service: Check if links to TOS, refund policies, or disclaimers are visible.
• Accessibility (WCAG): Ensure text has sufficient contrast (use WebAIM Contrast Checker), and interactive elements are keyboard-navigable.

Pro Tip:#

Use the GDPR Cookie Compliance plugin to manage consent banners, and test with screen readers (e.g., NVDA) for accessibility.

13. Conduct a Content Review#

Even minor theme changes can break content formatting. A thorough content review ensures nothing is missing or misaligned.

What to Review:#

• Key Pages: Home, About, Contact, Services, and blog posts.
• Formatting: Bold/italics, bullet lists, blockquotes, and code snippets.
• Media: Images, videos, and PDFs should display correctly (no broken links or distorted sizes).
• Links: Test internal links (e.g., “Read More” buttons) and external links (e.g., social media).
• Forms: Submit test entries for contact forms (e.g., Contact Form 7), newsletter signups (e.g., Mailchimp), and e-commerce carts (e.g., WooCommerce).

How to Streamline:#

Create a checklist for each page type (e.g., “Blog Post Checklist” with items: “H1 present,” “Images optimized,” “Comments enabled”).

14. Gather Feedback#

Even if you think the new theme works, others may spot issues (e.g., confusing navigation or hard-to-read text).

Who to Ask:#

• Team Members: Colleagues can test functionality (e.g., “Can you submit a contact form?”).
• Users/Customers: Send a survey via email or social media with questions like:
  • “Is the new design easier to navigate?”
  • “Did you notice any broken links or missing content?”
• Peers: Share the staging site with other WordPress developers for technical feedback (e.g., “Is the theme using semantic HTML?”).

Tools to Collect Feedback:#

• Google Forms: Create a survey with rating scales and open-ended questions.
• Hotjar: Use heatmaps to see where users click and session recordings to spot navigation issues.
• Comments: Add a feedback widget (e.g., WP Feedback) to the staging site.

15. Prepare for Post-Switch Checks#

After switching themes on your live site, monitor for issues that may not have appeared on staging (e.g., server-specific errors).

What to Monitor:#

• Errors: Check for 404s (use MonsterInsights or Google Search Console), PHP errors (via wp-config.php: define('WP_DEBUG', true);), or white screens of death (WSOD).
• Traffic/SEO: Use Google Analytics to watch for drops in traffic or bounce rate spikes.
• User Activity: Ensure comments, form submissions, and e-commerce purchases are working (test with a dummy order).

Tools for Post-Switch Monitoring:#

• UptimeRobot: Free tool that alerts you if your site goes down.
• Sucuri: Monitors for malware and errors.
• Google Search Console: Checks for indexing issues (e.g., “Crawling Error: Server Error 5xx”).

Conclusion#

Changing a WordPress theme is exciting, but it requires careful planning. By following these 15 steps—from backing up your site to testing performance—you’ll minimize risks and ensure a seamless transition. Remember: The goal isn’t just to switch themes, but to maintain (or improve!) your site’s functionality, design, and user experience.

Take your time, test thoroughly, and don’t hesitate to revert to your backup if something goes wrong. With preparation, your new theme will elevate your site without the stress.

References#

• WordPress Theme Handbook: Switching Themes
• UpdraftPlus Backup Plugin
• WP Staging Plugin
• GTmetrix Performance Testing
• Yoast SEO Plugin
• Google PageSpeed Insights
• GDPR Cookie Compliance Plugin
• WebAIM Contrast Checker