Nuxt 3 & Brotli Compression: A Deep Dive Into Hydration Mismatch Solutions

🧠 Understanding Hydration Mismatch

• Hydration mismatch occurs when there's a discrepancy between the initial HTML sent by the server and the client-rendered content.
• During server-side rendering, Nuxt sends a pre-rendered HTML along with JavaScript code to the client.
• This HTML is then "hydrated" by the client-side JavaScript, turning it into interactive components.

However, if there are differences between the initial HTML and the client-rendered content, a mismatch arises. This can happen due to various reasons, including:

• Incorrect HTML code. Using div tag inside p tag is invalid. ( This is the most common and easy to solve )
• Cloudflare Brotli Compression Settings - 😨 ( We will talk about this reason in this article Since this is not much common and it is difficult sometimes to strike )

✨ Example Scenarios

• Let's consider a scenario where a Nuxt application uses Cloudflare's aggressive Brotli compression.
• The server-side rendered HTML contains certain DOM nodes and JavaScript code.
• However, due to the high compression settings, the JavaScript code received on the client side might be slightly altered.
• As a result, when the client-side rendering kicks in, it doesn't match the initial HTML, leading to a hydration mismatch.

      <!-- Server-side rendered HTML -->
  <div id="app">
  <!--  Just observe below line Client Side -->
    <div v-if="isReady"></div>  
    <p>Hello from server!</p>
  </div>
  <script>
    // JavaScript code
  </script>
  

     <!-- Client Side -->
  <div id="app">
  <!--  Here lies the problem -->
    <!--[-->  
    <p>Hello from server!</p>
  </div>
  <script>
    // JavaScript code
  </script>
  

🤔 Problem

• One of the problems associated with Cloudflare's Brotli compression settings is the removal of comments from the source code during compression.
• This can lead to discrepancies between the comments present in the server-side code and what the client-side JavaScript receives.

🔧 Solution

• Turn off Compression

Helpful Resources

• Cloudflare Documentation
• Stackoverflow
• Nuxt Rendering Modes

🚀 Conclusion

• Hydration mismatch issues can be frustrating for both developers and users.
• While Cloudflare's Brotli compression settings can provide substantial performance gains, they can inadvertently trigger discrepancies between server and client rendering.
• By understanding the impact of Brotli compression, adjusting settings wisely, and following best practices
• Happy coding! 💻🌟