Detecting JavaScript SEO Issues in Deepcrawl

Adam Gent
Adam Gent

On 29th September 2020 • 5 min read

The modern web is constantly evolving and JavaScript websites are becoming increasingly popular. At Deepcrawl we have added new metrics and reports to help identify common JavaScript SEO issues.

Important: These new reports and metrics are only calculated when a crawl has JavaScript rendering turned on.

What is JavaScript SEO?

JavaScript SEO is an SEO practice that focuses on making JavaScript websites search engine friendly. There are a variety of unique problems that SEOs need to deal with to make JavaScript websites friendly for search engines. These common issues include:

  1. Rendering speed
  2. Main thread activity
  3. Conflicting signals between HTML and JavaScript
  4. Blocked scripts
  5. Scripts in the head
  6. Content duplication
  7. User events
  8. Service workers

For more information read our JavaScript SEO guide which covers everything you need to know about making JavaScript websites search engine friendly 

What new metrics are available?

Deepcrawl have added a number of new metrics for those who have JavaScript SEO issues:


What new reports are available?

The new rendering issue metrics can be found in the Config > Rendering Reports.

Right now Deepcrawl has 4 reports which highlight JavaScript SEO issues.

Word Count Mismatch Report

Content is a critical element in ranking a page in search engine results. It is important to make sure that search engines can efficiently crawl and index content on a page. This report highlights the total difference in word count client-side (rendered DOM) and raw HTML (view-source).

Link Count Mismatch Report

Internal links are a crucial element of your website architecture. Using JavaScript to load internal links can cause a delay in search engines crawling and indexing content. Use this report to identify internal link count difference between client-side (rendered DOM) vs the raw HTML (view source).

Canonical Link Mismatch Report

A canonical tag is a strong signal to tell search engines which page you want to be the primary version of your content. Use this report to identify pages with canonical tag URL mismatches in rendered DOM and the raw HTML source.

Pages with a Broken <head>

If invalid HTML tags (such as images, iframes, etc) can break the <head> early and cause important meta tags (canonical, hreflang, meta robots) to be ignored by Google. Use this report to identify pages with a broken <head>.

To learn more about this issue we recommend reading more about breaking the <head>

How can I get started?

Any customer can access these metrics, all that is required is that the JavaScript rendering feature is enabled and the metrics will be captured in the next crawl.


That’s it. Now all future crawls will capture the new structured data metrics and reports.

Frequently Asked Questions

Will you be adding other JavaScript SEO issue metrics?

Our team will continue to monitor and gather feedback from our customers to identify any new JavaScript SEO issue metrics to our system.

Are these new reports available in the Google Data Studio connector?

Yes, all of these new reports are available in the Data Studio connector. If you have an existing data source or dashboard, you will need to go into the data source configuration and choose “Reconnect” 

Will the new metrics and reports be available in the API?

Yes. Please read our API documentation to understand how to start pulling the data into your own workflows.


As always please share any feedback as this helps to improve Deepcrawl. If you have any questions about these new metrics, please feel free to get in touch with our team.


Adam Gent
Adam Gent

Search Engine Optimisation (SEO) professional with over 8 years’ experience in the search marketing industry. I have worked with a range of client campaigns over the years, from small and medium-sized enterprises to FTSE 100 global high-street brands.

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