Rendering

Rendering is the step where a search engine runs a page’s code, including JavaScript, to build the version of the page a user would see in a browser. Google needs to render many modern pages before it can understand their full content, links and layout.

Written by Paul Hoda, SEO consultant since 2005. Last updated 8 November 2026.

Why rendering matters

In the early web, all content sat in the HTML that the server sent. Today many websites build parts of the page in the browser using JavaScript frameworks such as React, Vue or Angular. If the important text, links or images only appear after JavaScript runs, Google has to render the page to see them. If rendering fails or is delayed, that content may be ignored.

How Google renders pages

Google uses an up-to-date version of the Chrome browser, called the Web Rendering Service, to render pages. The process works in stages:

  1. Crawl: Googlebot fetches the raw HTML.
  2. Initial processing: Google reads what is already in the HTML, including links.
  3. Render queue: pages that need JavaScript are queued for rendering.
  4. Render: Google runs the JavaScript and captures the final page.
  5. Index: the rendered content is used for Indexing.

Rendering usually happens quickly, but it uses more resources than simple crawling, so problems are more likely on large or slow sites.

Server-side vs client-side rendering

  • Server-side rendering (SSR): the server sends complete HTML. Search engines and users see content immediately. This is the safest option for SEO.
  • Client-side rendering (CSR): the browser builds the page with JavaScript. Search engines must render it to see the content.
  • Static generation and hydration: pages are pre-built as HTML and then made interactive. This combines good SEO with modern features.
  • Dynamic rendering: serving pre-rendered HTML to bots and JavaScript to users. Google now treats this as a workaround rather than a recommended solution.

Common rendering problems

  • Content or links that only load after a user clicks, scrolls or interacts.
  • JavaScript or CSS files blocked by Robots.txt, so Google cannot run them.
  • Scripts that time out or throw errors.
  • Links created with click events instead of normal href attributes.
  • Important text injected late by third-party scripts.
  • Meta tags, such as canonical or noindex, that change after JavaScript runs, sending mixed signals.

AI crawlers used by tools such as ChatGPT often do not run JavaScript at all, so content that depends on it may be invisible to them. This makes server-rendered content even more important for AI search visibility.

How to test rendering

  • Use the URL Inspection tool in Google Search Console and view the rendered HTML and screenshot.
  • Use the Rich Results Test, which also shows rendered HTML.
  • Compare “view source” (raw HTML) with the browser’s inspected DOM. Anything only in the DOM depends on JavaScript.
  • Crawl the site with JavaScript rendering both on and off to spot differences.

Best practices

  1. Put essential content, headings and links in the initial HTML wherever possible.
  2. Use server-side rendering or static generation for important pages.
  3. Do not block resources Google needs to render the page.
  4. Keep JavaScript lean to help Page Speed and Core Web Vitals.
  5. Use real anchor links with href attributes for navigation.

For more detail on frameworks and single-page applications, read the JavaScript SEO entry.

Key Takeaways

  • Rendering is when Google runs a page’s code to see the final content.
  • Content and links that depend on JavaScript are at greater risk.
  • Server-side rendering or static generation is safest for SEO.
  • Many AI crawlers do not run JavaScript at all.
  • Compare raw HTML with the rendered page to find gaps.

Related Terms

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