How Google renders pages

Day 1: Crawling 2

Said on stage 1

What Google's documentation says 1

Day 2: Indexing 60

Shown on screen 15

Said on stage 28

What Google's documentation says 13

Analysis by the author 4

Day 3: Serving: Ranking, Search Console, and Performance 7

Shown on screen 1

Said on stage 4

Analysis by the author 2

Across days and sessions 27

1. Stage D2-C118 Day 2 · Lightning session D: Rendering and JavaScript

   To train Gemini models, Google renders every page just as it does for Search, so a page that renders correctly for Search also works for Gemini training, provided the site allows its content to be used for training.

   extends
   Slide D1-C039 Day 1 · How Search works and where's AI?

   Gemini is not part of Search, but it uses crawlers for data, shares some technologies such as tokenization and deduping, and grounds on the Search index.

2. Slide D2-C127 Day 2 · Lightning session D: Rendering and JavaScript

   A Google pipeline diagram ran from the crawl queue to the crawler, then through HTML parsing to processing, which passes pages to rendering and gets them back, and then to the index; rendering fetches its JavaScript and CSS through the crawler.

   extends
   Slide D1-C063 Day 1 · How crawling works

   The crawl pipeline runs from a crawl queue to a scheduler to the crawler, which fetches from the internet and passes the fetch reply to indexing.

3. Stage D2-C128 Day 2 · Lightning session D: Rendering and JavaScript

   Although Google's pipeline diagram shows rendering as part of indexing, Google's rendering is a detached system, kept separate because rendering is time-consuming and computationally expensive.

   extends
   Slide D2-C026 Day 2 · How is HTML interpreted

   A Google pipeline slide placed processing between the crawler and the index and listed six processing steps: HTML parsing, rendering, deduplication, feature extraction, signal extraction and index selection.

4. Slide D2-C167 Day 2 · Lightning session D: Rendering and JavaScript

   The diagram from Google's JavaScript SEO basics page shows a URL going from the crawl queue to the crawler, the crawled HTML going to processing, then the render queue and the renderer, whose rendered HTML returns to processing before the page reaches the index.

   extends
   Slide D1-C063 Day 1 · How crawling works

   The crawl pipeline runs from a crawl queue to a scheduler to the crawler, which fetches from the internet and passes the fetch reply to indexing.

5. Docs D2-C169 Day 2 · Lightning session D: Rendering and JavaScript

   Google's JavaScript SEO basics guide says Googlebot extracts links twice, from the HTML response before rendering and again from the rendered HTML, so links injected with JavaScript can be found if they use crawlable <a href> markup.

   extends
   Slide D1-C040 Day 1 · How Search works and where's AI?

   URL discovery works through links: a homepage links to section pages, which link to further pages.

6. Stage D2-C173 Day 2 · Lightning session D: Rendering and JavaScript

   Google's renderer is a headless Chromium that runs the page's JavaScript.

   extends
   Stage D1-C206 Day 1 · How Search works and where's AI?

   Google renders JavaScript-heavy pages from their HTML, CSS and JavaScript as a browser would, using the latest version of Chromium.

7. Slide D2-C195 Day 2 · Lightning session D: Rendering and JavaScript

   Content that loads only after a user action such as a click or a scroll is not in the DOM while Google renders the page, so Google cannot index it.

   extends
   Docs D1-C115 Day 1 · session not recorded

   Google's crawlers do not click buttons. Each page in a series needs its own URL and an <a href> link to the next page, should not use page 1 as its canonical, and rel=next and rel=prev are no longer used.

8. Slide D2-C204 Day 2 · Lightning session D: Rendering and JavaScript

   Blocking JavaScript or API resources in robots.txt is a classic rendering mistake: if Google's renderer cannot fetch a resource, it cannot run it.

   extends
   Slide D1-C064 Day 1 · How crawling works

   The crawler has multiple tasks: fetch from the internet, ensure it doesn't break the internet, and enforce robots.txt policies. Fetched data is sent for indexing.

9. Stage D2-C259 Day 2 · What is Google friendly JavaScript

   Erin Sparling named server-side or hybrid rendering, fallbacks and not leaving placeholders in the DOM, among other measures, as ways to guard against failed JavaScript rendering.

   extends
   Stage D2-C149 Day 2 · Lightning session D: Rendering and JavaScript

   A search engine's renderer does not wait forever before taking its snapshot, so content from slow internal systems or APIs can be missing and unresolved placeholders can end up in the final snapshot, a community speaker said.

10. Stage D2-C263 Day 2 · What is Google friendly JavaScript

    Content is missing from the rendered HTML either because the server does not serve it or because the content has still not appeared after some period of time.

    extends
    Stage D2-C149 Day 2 · Lightning session D: Rendering and JavaScript

    A search engine's renderer does not wait forever before taking its snapshot, so content from slow internal systems or APIs can be missing and unresolved placeholders can end up in the final snapshot, a community speaker said.

11. Stage D2-C268 Day 2 · What is Google friendly JavaScript

    Content that loads only when a user clicks an element is not supported in the way Google renders pages for indexing.

    extends
    Docs D1-C115 Day 1 · session not recorded

    Google's crawlers do not click buttons. Each page in a series needs its own URL and an <a href> link to the next page, should not use page 1 as its canonical, and rel=next and rel=prev are no longer used.

12. Stage D2-C271 Day 2 · What is Google friendly JavaScript

    Google does not scroll a page when it renders it for indexing, so content that infinite scroll loads on scroll-depth triggers works for users but is never loaded for Google.

    extends
    Stage D1-C114 Day 1 · Q&A

    A Google panelist called pagination one of the trickiest things in web development and said switching to infinite scroll or a load-more button is risky, depending on what you want to achieve, because Googlebot does not click buttons.

13. Stage D2-C271 Day 2 · What is Google friendly JavaScript

    Google does not scroll a page when it renders it for indexing, so content that infinite scroll loads on scroll-depth triggers works for users but is never loaded for Google.

    extends
    Stage D1-C491 Day 1 · Q&A

    If paginated pages are replaced by a load-more button or infinite scroll without crawlable links to them, Google will not see the further pages at all.

14. Stage D2-C272 Day 2 · What is Google friendly JavaScript

    Instead of scrolling, Google renders a page in a very tall viewport, around 10,000 pixels high.

    extends
    Slide D2-C199 Day 2 · Lightning session D: Rendering and JavaScript

    An Intersection Observer fires when the observed element enters the viewport, and the viewport Google renders with is tall, so content lazy-loaded this way can load during rendering.

15. Stage D2-C852 Day 2 · Controlling indexing

    When Google finds a noindex rule in a page's HTML, it drops the page without even processing its JavaScript, so a script cannot switch the page back to indexable, John Mueller said.

    extends
    Slide D2-C108 Day 2 · Controlling indexing

    Removing a robots restriction such as noindex with JavaScript does not work, a slide said.

16. Stage D2-C853 Day 2 · Controlling indexing

    John Mueller recommended putting robots meta tags directly in a page's HTML exactly as intended, and adding them with JavaScript only where that is not possible, as in a JavaScript web app.

    extends
    Slide D2-C106 Day 2 · Controlling indexing

    A slide said robots meta rules can be added to a page's HTML with JavaScript, but doing so takes more time.

17. Stage D3-C626 Day 3 · How long does it take to..?

    Google renders pages in two ways: immediately after crawling, or later through a queue-based process that runs elsewhere.

    extends
    Slide D2-C170 Day 2 · Lightning session D: Rendering and JavaScript

    After processing, an indexable page is placed in Google's render queue to wait for rendering.

18. Stage D3-C627 Day 3 · How long does it take to..?

    Content that JavaScript adds to a page is typically seen by Google's indexing system within a few hours, and at worst within weeks.

    extends
    Docs D2-C172 Day 2 · Lightning session D: Rendering and JavaScript

    Google's JavaScript SEO basics guide says a page may wait in the render queue for a few seconds but that it can take longer, and it gives no upper limit.

19. Stage D3-C628 Day 3 · How long does it take to..?

    Gary Illyes said Google keeps saying it renders every URL on the internet and that he would say this is not true, though it is what he was told; he went on to say that Google's logs show the rendering queue cleared within weeks.

    extends
    Stage D2-C256 Day 2 · What is Google friendly JavaScript

    Google renders nearly all of the web by replicating what a browser does, using a real browser's rendering engine.

20. Analysis D3-C676 Day 3 · How long does it take to..?

    The stage doubt that every URL gets rendered sits beside Google's JavaScript guide, which says every page with a 200 status is queued for rendering unless a robots rule blocks indexing: queued is not the same as rendered, so do not rely on rendering for critical content.

    extends
    Docs D2-C131 Day 2 · Lightning session D: Rendering and JavaScript

    Google's JavaScript SEO guide says Googlebot sends every page with a 200 HTTP status code to the rendering queue, whether or not it contains JavaScript, unless a robots meta tag or header tells Google not to index it, and Google uses the rendered HTML to index the page.

21. Stage D2-C126 Day 2 · Lightning session D: Rendering and JavaScript

    Google renders pages with Chromium, the browser technology that also underlies Chrome, Edge and other Chromium-based browsers.

    repeats
    Stage D1-C206 Day 1 · How Search works and where's AI?

    Google renders JavaScript-heavy pages from their HTML, CSS and JavaScript as a browser would, using the latest version of Chromium.

22. Slide D2-C262 Day 2 · What is Google friendly JavaScript

    Content that is not in the final DOM after rendering cannot be seen by Google, so it cannot be indexed.

    repeats
    Slide D2-C174 Day 2 · Lightning session D: Rendering and JavaScript

    Whatever is in the DOM at the moment Google's rendering finishes is what likely gets indexed.

23. Slide D2-C265 Day 2 · What is Google friendly JavaScript

    Blocked resources, one of Google's four common JavaScript indexing problems, means robots.txt disallowing the crawling of critical JavaScript files or API endpoints.

    repeats
    Slide D2-C204 Day 2 · Lightning session D: Rendering and JavaScript

    Blocking JavaScript or API resources in robots.txt is a classic rendering mistake: if Google's renderer cannot fetch a resource, it cannot run it.

24. Stage D2-C268 Day 2 · What is Google friendly JavaScript

    Content that loads only when a user clicks an element is not supported in the way Google renders pages for indexing.

    repeats
    Slide D2-C195 Day 2 · Lightning session D: Rendering and JavaScript

    Content that loads only after a user action such as a click or a scroll is not in the DOM while Google renders the page, so Google cannot index it.

25. Stage D2-C271 Day 2 · What is Google friendly JavaScript

    Google does not scroll a page when it renders it for indexing, so content that infinite scroll loads on scroll-depth triggers works for users but is never loaded for Google.

    repeats
    Slide D2-C197 Day 2 · Lightning session D: Rendering and JavaScript

    Lazy loading triggered by a scroll event listener, such as window.addEventListener('scroll', loadMoreProducts), never runs for Googlebot because Googlebot does not scroll.

26. Stage D2-C274 Day 2 · What is Google friendly JavaScript

    Content loaded as elements enter the viewport, for example with an Intersection Observer, does load when Google renders a page, because Google's rendering viewport is very tall.

    repeats
    Slide D2-C199 Day 2 · Lightning session D: Rendering and JavaScript

    An Intersection Observer fires when the observed element enters the viewport, and the viewport Google renders with is tall, so content lazy-loaded this way can load during rendering.

27. Stage D2-C296 Day 2 · What is Google friendly JavaScript

    If robots.txt blocks JavaScript that client-side code needs to render, Google cannot render the content that the JavaScript would produce.

    repeats
    Slide D2-C204 Day 2 · Lightning session D: Rendering and JavaScript

    Blocking JavaScript or API resources in robots.txt is a classic rendering mistake: if Google's renderer cannot fetch a resource, it cannot run it.

Built on these claims 15

Developer requirements 15

• ShouldDocumentedDEV-REN-01

  Server-render the main content and everything indexing depends on (SSR, static generation or hybrid)

  Rests on 11 claims, 7 of them in this topic

• MustDocumentedDEV-REN-02

  Have all indexable content in the DOM after load, without clicks, typing or scrolling

  Rests on 8 claims, 5 of them in this topic

• AvoidDocumentedDEV-REN-05

  Do not add, change or remove robots meta tags with JavaScript

  Rests on 9 claims, 5 of them in this topic

• ShouldDocumentedDEV-REN-06

  Make rendering robust: no slow API dependencies and no unresolved placeholders

  Rests on 8 claims, 5 of them in this topic

• ShouldDocumentedDEV-REN-08

  Feature-detect permission-based APIs and WebGL, and render the content without them

  Rests on 5 claims, 4 of them in this topic

• MustDocumentedDEV-REN-03

  Lazy-load with native lazy loading or an IntersectionObserver, never with scroll events

  Rests on 6 claims, 3 of them in this topic

• MustDocumentedDEV-URL-07

  Back infinite scroll and load-more buttons with paginated URLs

  Rests on 6 claims, 3 of them in this topic

• AvoidDocumentedDEV-REN-04

  Do not block JavaScript, CSS or API endpoints that pages need for rendering in robots.txt

  Rests on 7 claims, 2 of them in this topic

• ShouldDocumentedDEV-REN-10

  Keep indexable content out of iframes, and check web components in the rendered HTML

  Rests on 4 claims, 2 of them in this topic

• MayDocumentedDEV-IDX-11

  Use the Google-Extended robots.txt token to control Gemini training and grounding

  Rests on 8 claims, 1 of them in this topic

• ShouldDocumentedDEV-MON-04

  Monitor Crawl stats and server logs for verified Googlebot traffic

  Rests on 13 claims, 1 of them in this topic

• ShouldDocumentedDEV-MON-10

  Plan releases and fixes around Google's processing times, and judge results only after them

  Rests on 11 claims, 1 of them in this topic

• ShouldDocumentedDEV-PRF-02

  Make JavaScript-generated content render quickly

  Rests on 5 claims, 1 of them in this topic

• ShouldDocumentedDEV-PRF-04

  Keep each HTML response well under 2 MB and put the main content and JSON-LD early

  Rests on 2 claims, 1 of them in this topic

• MustDocumentedDEV-URL-01

  Make every navigational link an <a> element whose href holds a real URL

  Rests on 6 claims, 1 of them in this topic

Sources 11

• Understand the JavaScript SEO basics Google Search Central · checked 3 October 2026
• In-depth guide to how Google Search works Google Search Central · checked 3 October 2026
• Inside Googlebot: demystifying crawling, fetching, and the bytes we process Search Central blog (31 March 2026) · checked 3 October 2026
• Crawling December: The how and why of Googlebot crawling Search Central blog (3 December 2024) · checked 2 October 2026
• Fix Search-related JavaScript problems Google Search Central · checked 2 October 2026
• Mobile site and mobile-first indexing best practices Google Search Central · checked 2 October 2026
• Fix lazy-loaded content Google Search Central · checked 2 October 2026
• March 2023 Google SEO office hours Google Search Central (SEO office hours transcript, March 2023) · checked 2 October 2026
• Introduction to robots.txt Google Search Central · checked 4 October 2026
• Pagination, incremental page loading, and their impact on Google Search Google Search Central · checked 3 October 2026
• Dynamic rendering as a workaround Google Search Central · checked 2 October 2026