Does Google really overlook the scripts and extra content on your pages?

What is tokenization and why does Google filter HTML?

When Googlebot crawls a page, it doesn’t blindly store the entire source code on its servers. That would be a monumental waste of resources. Instead, Google applies a tokenization process: breaking the document into minimal units (tokens), eliminating what is unnecessary for ranking, and retaining only the essentials.

JavaScript scripts, for example, often contain thousands of lines of code, comments, cryptic variable names. None of that has semantic value for understanding the topic of the page. Google discards them. The same applies to tracking tags, redundant inline CSS attributes, nested divs without textual content. The engine retains only what corresponds to actual content visible to the user.

Does this statement mean that JavaScript is ignored by Google?

No, and that’s where many people misunderstand. Google executes JavaScript before tokenization. If your script generates text content that displays on screen, that text will indeed be indexed — but not the JavaScript code itself. This nuance is crucial.

On the other hand, if your JS is poorly optimized, too slow, or if the content only loads during user interactions (onclick, poorly configured infinite scroll), Google may never see that content. Because it will have abandoned the rendering before it could. This is a crawl and render budget issue, not a tokenization problem.

What HTML elements are considered "unnecessary"?

Google never provides an exhaustive list — obviously. But we can deduce from field tests that the following are eliminated: HTML comments, <script> tags and their content, much of the inline style attributes, redundant metadata (multiple identical tags), empty tags without text or alt/title attributes.

In contrast, retained are: visible text, semantic tags (h1-h6, strong, em), alt attributes for images, links (href), structured data (JSON-LD), probably certain aria attributes for accessibility. In short, everything that helps understand the meaning and structure of the page.

• Google tokenizes HTML: it keeps the essentials, discards the unnecessary (scripts, comments, empty tags).
• JavaScript is executed before tokenization — but only the content rendered on screen counts.
• Semantic elements (headings, links, alt, structured data) survive filtering and contribute to ranking.
• Optimizing the weight of HTML doesn't help with indexing — what matters is the rendering speed and quality of visible content.
• Hidden content (display:none, JS conditional visibility) may never be indexed if Google doesn't see it during the first render.

Is this statement consistent with observed practices in the field?

Yes, completely. We’ve known for years: Google does not store raw HTML. Cache tests, snippets displayed in SERPs, featured snippets — all indicate that Google works with a cleaned and simplified version of the document. Pros who have inspected crawl logs know that the weight of HTML has never been a direct ranking factor.

Where it gets tricky is on poorly designed sites that drown their content with tons of JavaScript or unnecessary tags. If your HTML is 500 KB and 90% of it is inline script, Google will take longer to extract the 10% of useful content. The result: wasted crawl budget, slowed rendering, partial indexing. Not because Google refuses to store the code — but because it never manages to see the final text.

What nuances should be added to this statement?

Gary Illyes speaks of tokenization, not crawl or rendering. It’s a step after Googlebot has retrieved and executed the page. If your content does not display during the initial rendering, it will never be tokenized — thus never indexed, regardless of how many scripts you pile on. [To check]: Google never specifies how long it waits before considering rendering complete. It is estimated to be 5 to 10 seconds max, but this is declarative from conferences, not official specs.

Another point: certain types of scripts can indirectly influence SEO. A script that generates a JSON-LD breadcrumb, for example, will be executed and its output will be indexed. The code of the script, no. But its result, yes. A subtle but critical nuance. Likewise, Web Components: if the shadow DOM exposes textual content, Google will see it — if done correctly. Otherwise, you lose everything.

In what cases does this rule not apply or pose problems?

On poorly optimized SPAs (Single Page Applications), this rule can become a nightmare. If your JS framework loads content asynchronously after the first paint, Google may see only an empty shell. Tokenization won’t help: it will only retain a few words from the loader. The result: indexed page with zero useful content.

The same issue arises on sites with conditional content based on user interactions (accordions, tabs, modals). If the text is in the DOM but hidden in CSS and Google does not trigger the JS event to display it, it will never be tokenized. [To check]: Google claims to index hidden content in accordions if it is present in the initial HTML, but field tests show inconsistent results depending on the frameworks used.

What concrete actions should you take to ensure Google properly indexes your content?

First action: test the rendering of your pages in Google Search Console. The URL inspection tool shows you exactly what Googlebot sees after executing the JavaScript. If text blocks are missing, they will never be tokenized — and thus never ranked. Pay special attention to dynamically generated content, accordions, lazy-loaded sections.

Second point: favor Server-Side Rendering (SSR) or static generation for critical content. If your main text is already present in the initial HTML, Google doesn't have to wait for the JS to execute. Tokenization happens immediately, without depending on the render budget. This is especially true for product sheets, blog articles, and SEO landing pages.

What errors should absolutely be avoided?

Never place important SEO content solely in scripts. A typical example: a text block stored in a JavaScript variable and injected into the DOM on click. Google will never read that variable. The code will be discarded during tokenization, and the text will never display if the event is not triggered.

Avoid HTML comments stuffed with keywords — this is an outdated black hat technique from the 2000s. Google simply discards them. The same logic applies to <noscript> tags: they only serve if JS is disabled, which never happens with modern Googlebot. No need to hide content there.

How to check if your site adheres to best practices?

Use Screaming Frog in JavaScript rendering mode and compare with a raw HTML crawl. The differences show you which contents depend on JS. If critical elements (H1, first paragraphs, product descriptions) only appear in JS mode, it's a red flag. Google may index them, but you are at its mercy — and its render budget.

Set up regular server log monitoring. If you see Googlebot crawling but indexing stagnates, there’s often a rendering problem or invisible content. Cross-check with Search Console data: if pages are crawled but marked as “Explored, currently not indexed,” it’s likely that tokenization found nothing substantial to store.

• Inspect all strategic pages in Google Search Console to verify final rendering.
• Favor SSR or static generation for high SEO value content.
• Remove unnecessary scripts and lighten the weight of HTML to speed up rendering.
• Test conditional content (accordions, tabs) to ensure they are present in the initial DOM.
• Crawl the site in JS mode and raw HTML mode to detect critical gaps.
• Monitor crawl logs and indexing rates to identify problematic pages.