JavaScript: 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.

How to Analyse in the SEO Spider

Enable JavaScript rendering mode via ‘Config > Spider > Rendering’ and select ‘JavaScript’ to crawl JavaScript websites.

View URLs with this issue in the ‘JavaScript’ tab and ‘H1 Updated by JavaScript’ filter, and export all URLs using the ‘Export’ button.

The ‘HTML H1’ column shows the <h1> found in the original HTML before JavaScript.

The ‘Rendered HTML H1’ column shows the <h1> found in the rendered HTML after JavaScript has been processed.

Read our tutorial on ‘How To Crawl JavaScript Websites‘.

What Triggers This Issue

This issue is triggered when the <h1> element present in the raw HTML of a webpage is modified by JavaScript, resulting in a different <h1> in the rendered HTML.

For example:

https://www.screamingfrog.co.uk/technical-seo/

Has the <h1>:

<h1>Technical SEO Agency</h1>

In the raw HTML, but this is changed to:

<h1>Technical SEO Consultants</h1>

After JavaScript is executed.

How To Fix

While Google is able to render pages and see client-side only content, consider including important content server side in the raw HTML.