How to Troubleshoot JavaScript SEO Issues

Last Updated: October 24, 2025

Your modern JavaScript website looks fantastic, runs smoothly for users, but... crickets from Google? Organic traffic isn't growing, or worse, important pages aren't even getting indexed. Chances are, you have a JavaScript SEO issue.

As detailed in our Ultimate Guide to JavaScript SEO, how search engines crawl, render, and index JavaScript-heavy sites is complex. Things can easily go wrong, leaving your valuable content invisible to Googlebot.

Generic advice like "make sure Google can render your JS" isn't helpful. You need a systematic process to diagnose the exact point of failure. This guide provides a practical, step-by-step Standard Operating Procedure (SOP) for troubleshooting common JavaScript SEO issues using Google's own tools.

Chapter 1: The First Question: Is Google Seeing Your Content?

This is the absolute starting point. Before worrying about rankings, you must confirm if Googlebot can actually see the content generated by your JavaScript after rendering.

The Primary Tool: URL Inspection Tool (GSC)

This tool in Google Search Console is your window into Google's view of your page.

Actionable SOP:

Enter URL: Input the specific URL you're concerned about into the GSC URL Inspection Tool.
Test Live URL: Click the "Test Live URL" button. This forces Googlebot to fetch and render your page in real-time.
View Tested Page: Once the test completes, click "View Tested Page".
Critical Step - Check Rendered HTML: Go to the "HTML" tab. Do not look at the "Source" tab (initial HTML). Search within this rendered HTML for a unique sentence or phrase from the content you expect to see.
- If the content IS present: Good. Google can render your JS and see the content. Your issue might lie elsewhere (e.g., crawl budget, content quality).
- If the content IS NOT present: Problem Found. Googlebot is failing to render your critical content. Proceed to Chapter 2.
Check Screenshot: Briefly check the "Screenshot" tab. Does it visually resemble what a user sees? Gross visual discrepancies can indicate rendering problems.
Check More Info > Page Resources: Look for any resources (JS files, CSS files, API calls) listed as "Couldn't be loaded." This often points to resources blocked by robots.txt, which can break rendering.

Chapter 2: Diagnosing Rendering Failures

If the URL Inspection Tool confirms Google isn't seeing your content, here's how to find out why.

Issue 1: Blocked Resources

This is a common and easy-to-fix issue. If critical JavaScript files needed for rendering are disallowed in your robots.txt, the WRS cannot execute them.

Diagnosis: The "Page Resources" section in the URL Inspection Tool's "More Info" tab will list blocked resources.
Fix: Adjust your robots.txt file to Allow crawling of necessary JS, CSS, and API endpoints. Retest with the URL Inspection Tool.

Issue 2: JavaScript Errors During Rendering

Your code might run fine in your browser but throw errors in Google's WRS environment.

Diagnosis: In the "View Tested Page" output of the URL Inspection Tool, go to the "More Info" tab and look at the "JavaScript Console Messages." Look for any red error messages.
Fix: Provide these specific error messages to your development team. They often point to issues with incompatible code, missing polyfills, or environment-specific problems.

Issue 3: Rendering Timeouts

Google's WRS has finite resources. If your page takes too long to execute its JavaScript and become stable, Google might give up before rendering is complete.

Diagnosis: This is harder to pinpoint directly. Symptoms include:
- Consistently missing content in the rendered HTML test, despite no blocked resources or console errors.
- Very poor performance scores in PageSpeed Insights, especially Time To Interactive (TTI) or Total Blocking Time (TBT).
- Very high INP scores reported in GSC's Core Web Vitals report for this URL group.
Fix: This requires significant performance optimization. Focus on reducing JavaScript bundle sizes, code-splitting, breaking up Long Tasks (see our guide on improving INP), and potentially moving from CSR to SSR or SSG.

Issue 4: Content Requires Interaction (Clicks, Scrolls)

Googlebot does not typically interact with a page like a user. Content hidden behind tabs, accordions that require clicks, or infinite scrolls might not be discovered or fully indexed.

Diagnosis: Check the rendered HTML in the URL Inspection Tool. Is the hidden content present? If not, Google isn't seeing it.
Fix:
- Ensure all critical content is present and visible in the initially rendered HTML without requiring interaction.
- Use standard <a> tags with href attributes for pagination or loading more content, rather than relying solely on JavaScript buttons without proper fallbacks.

Chapter 3: Diagnosing Indexing Issues (Content is Rendered, But Not Ranking)

If the URL Inspection Tool shows Google can render your content correctly, but the page still isn't indexed or ranking, the problem is likely not JavaScript rendering itself, but other factors:

noindex Tag: Double-check the rendered HTML for a <meta name="robots" content="noindex"> tag or an X-Robots-Tag: noindex HTTP header. The URL Inspection Tool's main summary will also report this.
Canonicalization Issues: Is a rel="canonical" tag pointing elsewhere? Google might be consolidating signals to a different URL. Check the "Indexing" section of the URL Inspection Tool.
Low Content Quality / Duplication: The content might be rendered correctly but deemed too thin, duplicative, or low-quality by Google's algorithms.
Crawl Budget Limitations: Google might be able to render the page, but simply doesn't have enough resources allocated to crawl and render all your pages frequently, especially on large PSEO sites. Log file analysis is needed here.

Expert Insight:
"Don't assume Google renders everything perfectly every time. We audited a large React site where the URL Inspection Tool sometimes showed the content, and sometimes didn't. Log file analysis revealed Googlebot was hitting the page, but the server occasionally timed out serving the critical API call needed to populate the content during rendering. The issue wasn't the JavaScript itself, but the backend reliability during the rendering window. Always look at the full picture: crawl, render, index."

Conclusion: A Systematic Approach Wins

Troubleshooting JavaScript SEO issues requires a methodical approach. Start by verifying if Google can see your content using the URL Inspection Tool's live test and rendered HTML view. If not, investigate blocked resources, console errors, and performance bottlenecks. If Google can see the content, shift your focus to indexing directives, canonicalization, content quality, and overall crawl efficiency.

By systematically isolating the point of failure, you can provide your development team with the precise information needed to fix the issue and unlock your JavaScript content's full SEO potential.