Fixing Search-Related JavaScript Issues

Fixing Search-related JavaScript Problems

This guide helps you identify and fix JavaScript issues preventing your page or specific content from appearing in Google Search results. While Google Search executes JavaScript, certain differences and limitations affect how crawlers access and render your content.

For more information on optimizing your JavaScript site for Google Search, refer to our guide on JavaScript SEO basics.

Understanding Googlebot's Behavior

Googlebot prioritizes efficiently crawling the web without negatively impacting user experience. Both Googlebot and its Web Rendering Service (WRS) component identify and often skip resources not contributing to essential page content. This includes reporting requests, error logs not crucial for content display, and other similar requests deemed unnecessary for extracting essential content.

Important Note: Client-side analytics may not accurately reflect Googlebot and WRS activity on your site. Utilize the crawl stats report in Google Search Console for monitoring Googlebot and WRS activity and feedback.

Identifying and Troubleshooting JavaScript Issues

Follow these steps if you suspect JavaScript issues are hindering your page's visibility in Google Search:

1. Determine if JavaScript is the root cause: If unsure, start with our general debugging guide.

2. Test how Google crawls and renders your URL: Use the Rich Results Test or the URL Inspection Tool in Search Console to analyze loaded resources, JavaScript console output, rendered DOM, and more.

3. Collect and audit JavaScript errors: Monitor JavaScript errors encountered by users, including Googlebot. This helps identify potential issues affecting content rendering. Here's an example demonstrating how to log JavaScript errors using the global onerror handler:

   window.onerror = function(message, source, lineno, colno, error) {
     // Construct an error object with relevant details
     const errorData = {
       message: message,
       source: source,
       lineno: lineno,
       colno: colno,
       error: error ? error.toString() : '' // Safely access error object
     };
   
     // Send the error data to your server-side logging endpoint
     fetch('/your-logging-endpoint', {
       method: 'POST',
       headers: {
         'Content-Type': 'application/json'
       },
       body: JSON.stringify(errorData)
     });
   
     // Optionally display a user-friendly error message
     // ...
   };

   Note: Some errors, like parse errors, can't be logged this way.

4. Prevent soft 404 errors: Especially crucial for Single-Page Applications (SPAs). Utilize these strategies to avoid indexing error pages:

   • Redirect: Redirect to a URL where the server responds with a 404 status code.

   • Robots meta tag: Add or modify the robots meta tag to noindex.

   <meta name="robots" content="noindex"> 

   Important: SPAs using client-side JavaScript for error handling often return a 200 HTTP status code instead of the appropriate error code. This can lead to the indexing and potential display of error pages in search results.

5. Anticipate Googlebot declining user permission requests: Features requiring user permission aren't applicable to Googlebot. For instance, if your site requires access to the Camera API, provide alternative ways to access content without this requirement.

6. Avoid using fragment URLs for loading different content: While SPAs might employ fragment URLs (e.g., https://example.com/#/products) for loading different views, the AJAX-crawling scheme has been deprecated since 2015. Instead, leverage the History API to load content based on the URL in an SPA.

   // Example using History API
   const loadContent = (url) => {
     // Fetch content for the given URL
     fetch(url)
       .then(response => response.text())
       .then(html => {
         // Update the content area with the fetched HTML
         document.getElementById('content').innerHTML = html;
   
         // Update the browser history
         history.pushState({}, '', url);
       });
   };
   
   // Attach event listener for navigation links
   document.addEventListener('click', (event) => {
     if (event.target.tagName === 'A') {
       event.preventDefault(); // Prevent default link behavior
       const url = event.target.getAttribute('href');
       loadContent(url); 
     }
   });

7. Avoid relying on data persistence for serving content: WRS loads each URL individually and doesn't retain state across page loads. This means:

   • Local Storage and Session Storage data are cleared.

   • HTTP Cookies are cleared.

8. Utilize content fingerprinting to prevent caching issues: Googlebot's aggressive caching can lead WRS to use outdated resources. Content fingerprinting, which incorporates a content fingerprint into the filename (e.g., main.2bb85551.js), helps avoid this.

   Refer to the web.dev guide on long-lived caching strategies for more details.

9. Ensure feature detection and provide fallbacks: Not all user agents support all web features. Use feature detection for critical APIs and offer fallback mechanisms or polyfills.

   Example: If your application uses WebGL:

   if (window.WebGLRenderingContext) {
     // WebGL is supported, proceed with WebGL implementation
   } else {
     // WebGL is not supported, use a fallback mechanism
   }

10. Ensure compatibility with HTTP connections: Googlebot relies on HTTP requests. Provide HTTP fallbacks if your application utilizes other connection types like WebSockets or WebRTC.

11. Validate web component rendering: Utilize the Rich Results Test or the URL Inspection Tool to ensure your web components render as expected within the rendered HTML. WRS flattens the light DOM and shadow DOM, so ensure your components accommodate this. Refer to best practices for web components for more information.

Testing and Next Steps

After implementing the checklist items, retest your page using the Rich Results Test or the URL Inspection Tool in Google Search Console.

A green checkmark and the absence of errors indicate a successful fix.