JavaScript

JavaScript

The JavaScript tab contains data and filters around common issues related to auditing websites using client-side JavaScript.

This tab will only populate in JavaScript rendering mode (‘Configuration > Spider > Rendering tab > JavaScript’).

In JavaScript rendering mode, the SEO Spider will render web pages like in a browser, and help identify JavaScript content and links and other dependencies. JavaScript rendering mode is only available in the paid version.

Columns

This tab includes the following columns.

• Address – The URL address.
• Status Code – The HTTP response code.
• Status – The HTTP header response.
• HTML Word Count – This is all ‘words’ inside the body tag of the raw HTML before JavaScript, excluding HTML markup. The count is based upon the content area that can be adjusted under ‘Config > Content > Area’. By default, the nav and footer elements are excluded. You can include or exclude HTML elements, classes and IDs to calculate a refined word count. Our figures may not be exactly what performing this calculation manually would find, as the parser performs certain fix-ups on invalid HTML. Your rendering settings also affect what HTML is considered. Our definition of a word is taking the text and splitting it by spaces. No consideration is given to visibility of content (such as text inside a div set to hidden).
• Rendered HTML Word Count – This is all ‘words’ inside the body tag of the rendered HTML after JavaScript execution, excluding HTML markup. The count is based upon the content area that can be adjusted under ‘Config > Content > Area’. By default, the nav and footer elements are excluded. You can include or exclude HTML elements, classes and IDs to calculate a refined word count. Our figures may not be exactly what performing this calculation manually would find, as the parser performs certain fix-ups on invalid HTML. Your rendering settings also affect what HTML is considered. Our definition of a word is taking the text and splitting it by spaces. No consideration is given to visibility of content (such as text inside a div set to hidden).
• Word Count Change – This is the difference between the HTML Word Count and the Rendered HTML Word Count. Essentially, how many words are populated (or removed) due to JavaScript.
• JS Word Count % – This is the proportion of text that changes in the rendered HTML due to JavaScript.
• HTML Title – The (first) page title discovered on the page in the raw HTML before JavaScript.
• Rendered HTML Title – The (first) page title discovered on the page in the rendered HTML after JavaScript execution.
• HTML Meta Description – The (first) meta description discovered on the page in the raw HTML before JavaScript.
• Rendered HTML Meta Description- The (first) meta description discovered on the page in the rendered HTML after JavaScript execution.
• HTML H1 – The (first) h1 discovered on the page in the raw HTML before JavaScript.
• Rendered HTML H1- The (first) h1 discovered on the page in the rendered HTML after JavaScript execution.
• HTML Canonical – The canonical link element discovered on the page in the raw HTML before JavaScript.
• Rendered HTML Canonical – The canonical link element discovered on the page in the rendered HTML after JavaScript execution.
• HTML Meta Robots – The meta robots discovered on the page in the raw HTML before JavaScript.
• Rendered HTML Meta Robots – The meta robots discovered on the page in the rendered HTML after JavaScript execution.
• Unique Inlinks – Number of ‘unique’ internal inlinks to the URL. ‘Internal inlinks’ are links in anchor elements pointing to a given URL from the same subdomain that is being crawled. For example, if ‘page A’ links to ‘page B’ 3 times, this would be counted as 3 inlinks and 1 unique inlink to ‘page B’.
• Unique JS Inlinks – Number of ‘unique’ internal inlinks to the URL that are only in the rendered HTML after JavaScript execution. ‘Internal inlinks’ are links in anchor elements pointing to a given URL from the same subdomain that is being crawled. For example, if ‘page A’ links to ‘page B’ 3 times, this would be counted as 3 inlinks and 1 unique inlink to ‘page B’.
• Unique Outlinks – Number of unique internal outlinks from the URL. ‘Internal outlinks’ are links in anchor elements from a given URL to other URLs on the same subdomain that is being crawled. For example, if ‘page A’ links to ‘page B’ on the same subdomain 3 times, this would be counted as 3 outlinks and 1 unique outlink to ‘page B’.
• Unique JS Outlinks – Number of unique internal outlinks from the URL that are only in the rendered HTML after JavaScript execution. ‘Internal outlinks’ are links in anchor elements from a given URL to other URLs on the same subdomain that is being crawled. For example, if ‘page A’ links to ‘page B’ on the same subdomain 3 times, this would be counted as 3 outlinks and 1 unique outlink to ‘page B’.
• Unique External Outlinks – Number of unique external outlinks from the URL. ‘External outlinks’ are links in anchor elements from a given URL to another subdomain. For example, if ‘page A’ links to ‘page B’ on a different subdomain 3 times, this would be counted as 3 external outlinks and 1 unique external outlink to ‘page B’.
• Unique External JS Outlinks – Number of unique external outlinks from the URL that are only in the rendered HTML after JavaScript execution. ‘External outlinks’ are links in anchor elements from a given URL to another subdomain. For example, if ‘page A’ links to ‘page B’ on a different subdomain 3 times, this would be counted as 3 external outlinks and 1 unique external outlink to ‘page B’.

Filters

This tab includes the following filters.

• Pages with Blocked Resources – Pages with resources (such as images, JavaScript and CSS) that are blocked by robots.txt. This can be an issue as the search engines might not be able to access critical resources to be able to render pages accurately. Update the robots.txt to allow all critical resources to be crawled and used for rendering of the websites content. Resources that are not critical (e.g. Google Maps embed) can be ignored.
• Contains JavaScript Links – Pages that contain hyperlinks that are only discovered in the rendered HTML after JavaScript execution. These hyperlinks are not in the raw HTML. While Google is able to render pages and see client-side only links, consider including important links server side in the raw HTML.
• Contains JavaScript Content – Pages that contain body text that’s only discovered in the rendered HTML after JavaScript execution. While Google is able to render pages and see client-side only content, consider including important content server side in the raw HTML.
• Noindex Only in Original HTML – Pages that contain a noindex in the raw HTML, and not in the rendered HTML. When Googlebot encounters a noindex tag, it skips rendering and JavaScript execution. Because Googlebot skips JavaScript execution, using JavaScript to remove the ‘noindex’ in the rendered HTML won’t work. Carefully review pages with noindex in the raw HTML are expected to not be indexed. Remove the ‘noindex’ if the pages should be indexed.
• Nofollow Only in Original HTML – Pages that contain a nofollow in the raw HTML, and not in the rendered HTML. This means any hyperlinks in the raw HTML pre to JavaScript execution will not be followed. Carefully review pages with nofollow in the raw HTML are expected not to be followed. Remove the ‘nofollow’ if links should be followed, crawled and indexed.
• Canonical Only in Rendered HTML – Pages that contain a canonical only in the rendered HTML after JavaScript execution. Google can process canonicals in the rendered HTML, however they do not recommend relying upon JavaScript and prefer them earlier in the raw HTML. Problems with rendering, conflicting, or multiple rel=”canonical” link tags may lead to unexpected results. Include a canonical link in the raw HTML (or HTTP header) to ensure Google can see it and avoid relying only on the canonical in the rendered HTML only.
• Canonical Mismatch – Pages that contain a different canonical link in the raw HTML to the rendered HTML after JavaScript execution. Google can process canonicals in the rendered HTML after JavaScript has been processed, however conflicting rel=”canonical” link tags may lead to unexpected results. Ensure the correct canonical is in the raw HTML and rendered HTML to avoid conflicting signals to search engines.
• Page Title Only in Rendered HTML – Pages that contain a page title only in the rendered HTML after JavaScript execution. This means a search engine must render the page to see it. While Google is able to render pages and see client-side only content, consider including important content server side in the raw HTML.
• Page Title Updated by JavaScript – Pages that have page titles that are modified by JavaScript. This means the page title in the raw HTML is different to the page title in the rendered HTML. While Google is able to render pages and see client-side only content, consider including important content server side in the raw HTML.
• Meta Description Only in Rendered HTML – Pages that contain a meta description only in the rendered HTML after JavaScript execution. This means a search engine must render the page to see it. While Google is able to render pages and see client-side only content, consider including important content server side in the raw HTML.
• Meta Description Updated by JavaScript – Pages that have meta descriptions that are modified by JavaScript. This means the meta description in the raw HTML is different to the meta description in the rendered HTML. While Google is able to render pages and see client-side only content, consider including important content server side in the raw HTML.
• H1 Only in Rendered HTML – Pages that contain an h1 only in the rendered HTML after JavaScript execution. This means a search engine must render the page to see it. While Google is able to render pages and see client-side only content, consider including important content server side in the raw HTML.
• H1 Updated by JavaScript – Pages that have h1s that are modified by JavaScript. This means the h1 in the raw HTML is different to the h1 in the rendered HTML. While Google is able to render pages and see client-side only content, consider including important content server side in the raw HTML.
• Uses Old AJAX Crawling Scheme URLs – URLs that are still using the Old AJAX crawling scheme (a URL containing a #! hash fragment) which was officially deprecated as of October 2015. Update URLs to follow JavaScript best practices on the web today. Consider server-side rendering or pre-rendering where possible, and dynamic rendering as a workaround solution.
• Uses Old AJAX Crawling Scheme Meta Fragment Tag – URLs include a meta fragment tag that indicates the page is still using the Old AJAX crawling scheme which was officially deprecated as of October 2015. Update URLs to follow JavaScript best practices on the web today. Consider server-side rendering or pre-rendering where possible, and dynamic rendering as a workaround solution. If the site still has the old meta fragment tag by mistake, then this should be removed.
• Pages with JavaScript Errors – Pages with JavaScript errors captured in the Chrome DevTools console log during page rendering. While JavaScript errors are common and often have little effect on page rendering, they can be problematic – both in search engine rendering, which can hinder indexing, and for the user when interacting with the page. View console error messages in the lower ‘Chrome Console Log’ tab, view how the page is rendered in the ‘Rendered Page’ tab, and export in bulk via ‘Bulk Export > JavaScript > Pages With JavaScript Issues’.

For more information on JavaScript SEO, please read our guide on ‘How to Crawl JavaScript Websites‘.