# JavaScript frameworks

Category: [Rendering & JavaScript](https://seo-geo-glossary.com/en/glossary/category/rendering-javascript/) › [JavaScript & frameworks](https://seo-geo-glossary.com/en/glossary/category/rendering-javascript/javascript-frameworks/)

**JavaScript frameworks** such as React, Angular, and Vue are toolkits for building interactive web interfaces from reusable components. MDN describes them as tried-and-tested tools for scalable, interactive web applications. For SEO the key question is where a framework builds the HTML, on the server or in the browser.

## Which frameworks are there?

MDN lists React, Angular, Ember, Svelte, and Vue as options. Strictly speaking, React is a library, but it is usually grouped with the frameworks. Meta-frameworks such as Next.js, Nuxt, or Astro build on top of these and add routing and server-side rendering.

## Why do they matter for SEO?

A framework often delivers a nearly empty HTML document and creates the content once the JavaScript has run. Google processes such pages in three phases, crawling, rendering, and indexing, and uses a headless Chromium to execute the scripts. Content that only exists after rendering can be indexed, but it depends on the render step succeeding.

Google still recommends server-side rendering or pre-rendering, because it makes a site faster for users and crawlers and not all bots run JavaScript. web.dev compares three approaches. Server-side rendering can increase time to first byte. Static rendering needs the URLs to be known in advance. Client-side rendering tends to ship more JavaScript as an app grows, which can hurt performance on mobile devices.

Google's JavaScript guide adds a few rules for framework sites:

- Use the History API for routing instead of URL fragments.
- Return real status codes (404) or add a noindex robots meta tag to error views, otherwise soft 404s can be indexed.
- Add content hashes to file names, for example `main.2bb85551.js`, because Googlebot caches resources aggressively.

## Example

A React app without server-side rendering delivers this HTML:

```html
<div id="root">
<script src="/static/main.2bb85551.js"></script>
```

Title, text, and links appear only after the script has run. With a meta-framework the same project can place that content in the first HTML response.

## Common mistakes

- Error pages that return status 200, so Google treats them as normal pages.
- Navigation through URL fragments (`#/page`), which does not give each view its own URL.
- Key content that a render failure or a blocked script file hides from Google.
- File names without a content hash. Googlebot caches aggressively and its rendering service may ignore caching headers, so outdated JavaScript or CSS files can be used.
- A canonical URL set by JavaScript that differs from the value in the original HTML.

## FAQ

**Which JavaScript frameworks are most common?** MDN names React, Angular, Ember, Svelte, and Vue. Rankings shift often, so check a current developer survey.

**Are JavaScript frameworks bad for SEO?** The framework alone does not decide this. What counts is whether the important content is in the rendered HTML, ideally already in the first response.

*Diagram: Where the HTML is created: CSR, SSR, SSG.* What matters for crawlers is whether the content is already in the first HTML response. Google recommends server-side rendering or prerendering and calls dynamic rendering a workaround, not a long-term solution.

## Related terms

- [JavaScript SEO](https://seo-geo-glossary.com/en/glossary/javascript-seo/index.md)
- [JavaScript redirect](https://seo-geo-glossary.com/en/glossary/javascript-redirect/index.md)
- [Rendering](https://seo-geo-glossary.com/en/glossary/rendering/index.md)
- [Server-side rendering](https://seo-geo-glossary.com/en/glossary/server-side-rendering/index.md)
- [Client-side rendering](https://seo-geo-glossary.com/en/glossary/client-side-rendering/index.md)
- [Hydration](https://seo-geo-glossary.com/en/glossary/hydration/index.md)

## Sources

- [JavaScript frameworks and libraries - MDN Web Docs](https://developer.mozilla.org/en-US/docs/Learn_web_development/Core/Frameworks_libraries)
- [JavaScript SEO basics - Google Search Central](https://developers.google.com/search/docs/crawling-indexing/javascript/javascript-seo-basics)
- [Rendering on the Web - web.dev](https://web.dev/articles/rendering-on-the-web)

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Last updated: October 8, 2026
URL: https://seo-geo-glossary.com/en/glossary/javascript-frameworks/