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  3. 304 Not Modified

304 Not Modified

304 Not Modified is an HTTP status code that tells a browser it can use a saved version of a file instead of downloading it again.

When someone visits your website, their browser often saves (or “caches”) certain files like images, scripts, or stylesheets. If the visitor returns later, the browser checks with your website to see if anything has changed.

If nothing has changed, the server responds with a 304 Not Modified code. This tells the browser:

“No need to download the file again — you already have the most up-to-date version.”

Why Is 304 Important?

This status code helps improve your website’s performance in several key ways:

Benefits of 304 Not Modified:

  • 🚀 Faster loading — Pages open quicker because the browser uses cached content.
  • 💾 Saves bandwidth — Reduces the amount of data sent between your site and visitors.
  • 🔧 Lowers server load — Your server doesn’t have to resend files that haven’t changed.
  • 📈 Supports better SEO — Faster websites improve user experience and can help your rankings in search engines.

How Does It Work?

Here’s a simple step-by-step explanation:

  1. A visitor opens your site. The browser stores some files locally.
  2. When they come back, the browser checks with the server:
    “Has this file changed since last time?”
  3. If it hasn’t changed, the server replies:
    “304 Not Modified.”
  4. The browser uses the saved (cached) version instead of downloading it again.

Example in Real Life

Let’s say you visited a blog yesterday. Your browser saved the logo image. When you return today:

  • The browser asks the server if the logo has changed.
  • The server responds with 304 Not Modified.
  • The browser shows you the saved image instantly — no new download needed.

Do You Need to Worry About 304?

No! Seeing 304 status codes is a good thing. It means caching is working properly on your site.

However, if your website still loads slowly despite many 304 responses, it may be time to:

  • Check your caching settings.
  • Use a caching plugin (for WordPress, options like WP Rocket or LiteSpeed Cache help).
  • Ask your hosting provider for support — many handle caching automatically.
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