Google Just Changed How Noindex Handles JavaScript - What It Means For Your Site

Google warns noindex can block JavaScript from running

Google's JavaScript SEO basics guide now includes explicit guidance on robots meta tags for JavaScript based pages. The updated JavaScript SEO documentation states:

When Google encounters the noindex tag, it may skip rendering and JavaScript execution, which means using JavaScript to change or remove the robots meta tag from noindex may not work as expected.

The same section continues:

If you do want the page indexed, don't use a noindex tag in the original page code.

This guidance appears on the official JavaScript SEO basics page on Google's Search Central site and targets scenarios where JavaScript is used to alter indexing directives after the page loads.

Key details of Google's updated JavaScript SEO guidance

The clarification focuses on pages that initially respond with a noindex meta tag, then rely on JavaScript for later changes. It documents that Googlebot may decide not to render such pages at all, which means related JavaScript will not run.

Key factual points from Google's documentation and update log include:

• The clarification appears in the JavaScript SEO basics guide under guidance about robots meta tags on JavaScript pages.
• Google states it "may skip rendering and JavaScript execution" when it encounters a noindex tag.
• The documentation notes that JavaScript used to change or remove a noindex robots meta tag "may not work as expected."
• Google advises: "If you do want the page indexed, don't use a noindex tag in the original page code."
• On the Search documentation updates page, Google adds that the related behavior "is not well defined and might change."
• Both the guidance and the note appear on official Google Search Central properties managed by Google.

Background on Google rendering and noindex handling

Google's JavaScript SEO documentation explains that Googlebot can process JavaScript after initially crawling a page's HTML. Rendering may be deferred and handled by a separate system that executes scripts and then updates what gets indexed.

The new clarification makes clear that this rendering step may be skipped when a page is served with a noindex tag in the original HTML response. In its update log, Google characterizes the interaction between noindex and rendering as behavior that "is not well defined and might change," describing how Googlebot may treat JavaScript content on pages where a noindex directive is present from the start.

Source citations

• Google Search Central - JavaScript SEO documentation, section on robots meta tags and JavaScript.
• Google Search Central - Search documentation updates page describing the clarification on noindex tags and JavaScript rendering.