Google has released a new episode of its Search Central Lightning Talks, which focuses on rendering strategies, an important topic for web developers.
In this video, Martin Splitt, a Developer Advocate at Google, explains the intricacies of different rendering methods and how these approaches impact website performance, user experience, and search engine optimization (SEO).
This episode also connects to recent discussions about the overuse of JavaScript and its effects on AI search crawlers, a topic previously addressed by Search Engine Journal.
Splitt’s insights offer practical guidance for developers who want to optimize their websites for modern search engines and users.
What Is Rendering?
Splitt begins by explaining what rendering means in the context of websites.
He explains rendering in simple terms, saying:
“Rendering in this context is the process of pulling data into a template. There are different strategies as to where and when this happens, so let’s take a look together.”
In the past, developers would directly edit and upload HTML files to servers.
However, modern websites often use templates to simplify the creation of pages with similar structures but varying content, such as product listings or blog posts.
Splitt categorizes rendering into three main strategies:
- Pre-Rendering (Static Site Generation)
- Server-Side Rendering (SSR)
- Client-Side Rendering (CSR)
1. Pre-Rendering
Screenshot from: YouTube.com/GoogleSearchCentral, January 2025.Pre-rendering, also known as static site generation, generates HTML files in advance and serves them to users.
Splitt highlights its simplicity and security:
“It’s also very robust and very secure, as there isn’t much interaction happening with the server, and you can lock it down quite tightly.”
However, he also notes its limitations:
“It also can’t respond to interactions from your visitors. So that limits what you can do on your website.”
Tools such as Jekyll, Hugo, and Gatsby automate this process by combining templates and content to create static files.
Advantages:
- Simple setup with minimal server requirements
- High security due to limited server interaction
- Robust and reliable performance
Disadvantages:
- Requires manual or automated regeneration whenever content changes
- Limited interactivity, as pages cannot dynamically respond to user actions
2. Server-Side Rendering (SSR): Flexibility with Trade-Offs
Screenshot from: YouTube.com/GoogleSearchCentral, January 2025.Server-side rendering dynamically generates web pages on the server each time a user visits a site.
This approach enables websites to deliver personalized content, such as user-specific dashboards and interactive features, like comment sections.
Splitt says:
“The program decides on things like the URL, visitor, cookies, and other things—what content to put into which template and return it to the user’s browser.”
Splitt also points out its flexibility:
“It can respond to things like a user’s login status or actions, like signing up for a newsletter or posting a comment.”
But he acknowledges its downsides:
“The setup is a bit more complex and requires more work to keep it secure, as users’ input can now reach your server and potentially cause problems.”
Advantages:
- Supports dynamic user interactions and tailored content
- Can accommodate user-generated content, such as reviews and comments
Disadvantages:
- Complex setup and ongoing maintenance
- Higher resource consumption, as pages are rendered for each visitor
- Potentially slower load times due to server response delays
To alleviate resource demands, developers can use caching or proxies to minimize redundant processing.
3. Client-Side Rendering (CSR): Interactivity with Risks
Screenshot from: YouTube.com/GoogleSearchCentral, January 2025.Client-side rendering uses JavaScript to fetch and display data in the user’s browser.
This method creates interactive websites and web applications, especially those with real-time updates or complex user interfaces.
Splitt highlights its app-like functionality:
“The interactions feel like they’re in an app. They happen smoothly in the background without the page reloading visibly.”
However, he cautions about its risks:
“The main issue with CSR usually is the risk that, in case something goes wrong during transmission, the user won’t see any of your content. That can also have SEO implications.”
Advantages:
- Users enjoy a smooth, app-like experience without page reloads.
- It allows features like offline access using progressive web apps (PWAs).
Disadvantages:
- It depends heavily on the user’s device and browser.
- Search engines may have trouble indexing JavaScript-rendered content, leading to SEO challenges.
- Users might see blank pages if JavaScript fails to load or run.
Splitt suggests a hybrid approach called “hydration ” to improve SEO.
In this method, the server initially renders the content, and then client-side rendering handles further interactions.
Screenshot from: YouTube.com/GoogleSearchCentral, January 2025.How to Choose the Right Rendering Strategy
Splitt points out that there is no one-size-fits-all solution for website development.
Developers should consider what a website needs by looking at specific factors.
Splitt says:
“In the end, that depends on a bunch of factors, such as what does your website do? How often does the content change? What kind of interactions do you want to support? And what kind of resources do you have to build, run, and maintain your setup?”
He provides a visual summary of the pros and cons of each approach to help developers make informed choices.
Screenshot from: YouTube.com/GoogleSearchCentral, January 2025.Connecting the Dots: Rendering and JavaScript Overuse
This episode continues earlier discussions about the drawbacks of excessive JavaScript use, especially regarding SEO in the age of AI search crawlers.
As previously reported, AI crawlers like GPTBot often have difficulty processing websites that rely heavily on JavaScript, which can decrease their visibility in search results.
To address this issue, Splitt recommends using server-side rendering or pre-rendering to ensure that essential content is accessible to both users and search engines. Developers are encouraged to implement progressive enhancement techniques and to limit JavaScript usage to situations where it genuinely adds value.
See the video below to learn more about rendering strategies.
Featured Image: Screenshot from: YouTube.com/GoogleSearchCentral, January 2025
