# What Is Server-Side Rendering (SSR) vs CSR? > Server-side rendering builds each page as HTML on the server, so visitors and AI crawlers get the full content at once. How SSR compares with CSR and SSG. Source: https://pentaclay.com/glossary/server-side-rendering Glossary # What is server-side rendering (SSR)? Server-side rendering (SSR) is a way of delivering web pages in which the server builds the complete HTML for a page when it is requested, so the browser, search engines and AI crawlers receive the full content straight away. Also called SSR ## SSR vs CSR With client-side rendering (CSR), the server sends a nearly empty HTML file and a JavaScript bundle; the browser runs the JavaScript to build the page. With SSR, the server runs that work first and sends finished HTML, and JavaScript then makes the page interactive, a step called hydration. The difference is invisible to a person on a fast laptop. It matters a lot to anything that reads the raw HTML without running JavaScript. ## Why it matters for AI crawlers Googlebot can run JavaScript, though rendering may happen later than the first crawl. Many AI crawlers do not. A December 2024 analysis of crawler traffic by Vercel and MERJ found that the crawlers used by OpenAI, Anthropic and Perplexity fetched JavaScript files but did not execute them. So a client-side rendered page can look complete in a browser while ChatGPT, Claude or Perplexity see an empty shell with a loading spinner. SSR, or static generation, puts the content in the HTML they actually read. ## When to use SSR - Pages that change per visitor or per request, such as personalized or logged-in views - Content that changes too often to rebuild, such as live inventory or listings - Pages behind search or filters that must still be crawlable - For content that is the same for everyone, static generation is usually simpler and faster ## Example A product comparison page built as a client-side React app shows “Loading…” in its HTML. Rendered on the server, the same page’s HTML contains the table, headings and prices, so any crawler can read it. ## How we handle it Every page we build delivers its main content in the HTML, whether through static generation, SSR or a visual builder that pre-renders. When we take over a browser-only React site, such as one made with an AI app builder, we move it to server or static rendering first. See [Next.js development](https://pentaclay.com/services/nextjs-development). Read next - [Next.js development](https://pentaclay.com/services/nextjs-development) - [AI search optimization](https://pentaclay.com/services/ai-search-optimization) Last updated 15 November 2026 Related terms ## Terms that go with server-side rendering - [Client-side rendering (CSR) Client-side rendering (CSR) is a way of building web pages in which the server sends a mostly empty HTML file and the visitor’s browser runs JavaScript to fetch the content and draw the page.](https://pentaclay.com/glossary/client-side-rendering) - [Static site generation (SSG) Static site generation (SSG) is a way of building a website in which every page is turned into a finished HTML file ahead of time, during a build step, so the server only has to send ready-made files when someone visits.](https://pentaclay.com/glossary/static-site-generation) - [Next.js Next.js is an open-source framework, built on React and maintained by Vercel, for building websites and web applications that can render pages on the server, at build time or in the browser.](https://pentaclay.com/glossary/nextjs) - [Generative engine optimization (GEO) Generative engine optimization (GEO) is the practice of making a website’s content easy for AI systems that write answers, such as ChatGPT, Perplexity, Gemini and Google’s AI Overviews, to find, understand and cite as a source.](https://pentaclay.com/glossary/generative-engine-optimization) [All glossary terms](https://pentaclay.com/glossary) ## Questions about server-side rendering ### Can’t find your answer? Book a call and let’s talk. [Book a call](https://cal.com/pentaclay/discovery-call) Or email us at [contact@pentaclay.com](mailto:contact@pentaclay.com) Is SSR better for SEO than client-side rendering? Generally, yes. With SSR, the content is in the HTML on the first request, so every search engine and AI crawler can read it without running JavaScript. How can I tell if my site is client-side rendered? Open a page, choose View Page Source in the browser, and search for a sentence from the page. If the text is missing from the source but visible on screen, it is rendered in the browser. Are Framer and Webflow sites server-rendered? They publish pre-rendered HTML for each page, so the main content is in the source. Content loaded later by custom scripts or embeds may not be. Does SSR make a site slower? It can add server work on each request, which caching usually offsets. Visitors often see content sooner than with client-side rendering, because the browser does not have to build the page first. ## Your business grew up. Your website should too If customers need a demo just to understand what you sell, your website isn’t doing its job. - We sign an NDA on request. - You own the site, the code and every account once it’s paid. - Your first call is with Erfan, the founder. **Kazi Mohammed Erfan** Founder Don’t want to fill in the form? [Book a call directly](https://cal.com/pentaclay/discovery-call) ## Not sure? Ask AI about Pentaclay ### Pentaclay, in short Updated 17 Oct 2026 Pentaclay is a B2B website design agency for AI companies that sell to enterprises. We write, design and build marketing websites in Framer, Webflow and Next.js, and stay to help after launch. Pentaclay LLC is registered in New Mexico, USA; our team works from Dhaka, Bangladesh, with calls until 12:30pm US Eastern. Founded in 2023 by Kazi Mohammed Erfan, who brings 12 years of design experience.