Detects if website uses Client-Side or Server-Side Rendering
Evaluates whether a website is Client-Side Rendered (CSR) or Server-Side Rendered (SSR) by comparing HTML content with JavaScript enabled vs disabled.
This checker evaluates whether a website is Client-Side Rendered (CSR) or Server-Side Rendered (SSR) by making two requests to the same URL: one with JavaScript enabled and one with JavaScript disabled. It then compares the HTML content from both requests to determine the rendering approach. The checker uses a size-based comparison algorithm that calculates the percentage difference between the HTML sizes. If the size difference is more than 20%, the site is considered CSR.
| Status | Description | Test Logic |
|---|---|---|
| SUCCESS | Website is Server-Side Rendered (SSR). Content is pre-rendered on the server. | The checker compares HTML content size with JavaScript enabled vs disabled. If the size difference is ≤ 20%, the site is considered SSR. This indicates that most content is pre-rendered on the server and doesn't require JavaScript to display properly. |
| WARNING | Website is Client-Side Rendered (CSR). Content is dynamically generated by JavaScript. | The checker detects a size difference > 20% between HTML with JavaScript enabled vs disabled. This indicates that significant content is generated dynamically by JavaScript, making the site dependent on client-side rendering. |
| ERROR | Technical error occurred during checking (Playwright/browser issues). | Browser automation fails due to network issues, timeout, or Playwright exceptions. The checker includes retry logic for transient crashes but will return ERROR for persistent technical problems. |
| FAIL | Unexpected error or all retry attempts exhausted. | Fallback status when all retry attempts fail or an unexpected error occurs that doesn't fit into the ERROR category. This is a catch-all for system-level failures. |
Ignoring CSR/SSR warnings can lead to several risks: SEO Impact - CSR sites may have poor search engine visibility as crawlers prefer pre-rendered content; Performance Issues - CSR sites often have slower initial page loads and poor Core Web Vitals scores; Accessibility Problems - Content that requires JavaScript may be inaccessible to users with disabilities or those using assistive technologies; Crawler Compatibility - Search engine crawlers may not execute JavaScript properly, leading to incomplete content indexing; User Experience - Users on slow connections or with JavaScript disabled may see blank or broken pages.
Add this checker to your monitoring setup and start identifying issues on your websites today.