Google updated its JavaScript SEO documentation to clarify how its crawler handles noindex tags on pages that use JavaScript.
The update addresses a scenario where a page starts with noindex in the original response, and JavaScript later tries to change or remove that directive. Google’s guidance is that this approach may not work as expected.
What Changed
Google added clarification under its guidance about robots meta tags on JavaScript pages.
Google Search Central documentation says:
“When Google encounters the
noindextag, it may skip rendering and JavaScript execution, which means using JavaScript to change or remove the robotsmetatag fromnoindexmay not work as expected. If you do want the page indexed, don’t use anoindextag in the original page code.”
On the documentation updates page, Google adds context for the clarification, noting that while Google may be able to render a JavaScript page, the behavior “is not well defined and might change.”
Related: Google’s Martin Splitt Explains How To Find & Remove Noindex Tags
Why This Matters
When managing a JavaScript-heavy site, this affects how you handle indexing logic.
Some implementations add noindex when an API call fails or content doesn’t load. Others start with noindex and rely on JavaScript to remove it once content loads successfully.
Google’s update makes clear that if the page begins with noindex, Google may skip the rendering step where that JavaScript would run.
Don’t rely on JavaScript to “fix” an initial noindex. If there’s any chance you want the page indexed, keep noindex out of the original response and use server-side handling for error states (for example, appropriate status codes) when you truly want a page excluded.
Related: Google warns against excessive JavaScript use.
Looking Ahead
This is a documentation clarification, but it closes an important implementation gap.
If you’re auditing a JavaScript site for indexing issues, check whether any pages include noindex in the initial HTML while relying on JavaScript to remove it later. Those pages may not be eligible for indexing, even if they appear indexable in a fully rendered browser.
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