HTTP 304 Not Modified — Browser Cache Still Valid

HTTP 304 Not Modified tells the browser its cached version is still current. No data is transferred. This guide covers everything you need to know about this topic, including common causes, step-by-step solutions, and answers to frequently asked questions.

Here are the key things to understand: Status: 304 Not Modified. Category: 3xx Redirection. Cached version is still valid. No response body — saves bandwidth. Understanding these fundamentals will help you diagnose and resolve this issue more effectively.

The most common reasons this occurs include: Browser sent If-None-Match with ETag. Browser sent If-Modified-Since header. Resource has not changed since last request. Cache validation succeeded. Identifying the root cause is the first step toward finding the right solution.

To resolve this, follow these recommended steps: Use the cached version — no action needed. Check ETag headers for cache validation. Verify Last-Modified headers are set correctly. Configure proper cache headers on the server. If these steps do not resolve the issue, consider consulting additional resources or a qualified professional.

This article is part of our HTTP Status Codes collection on Error Codes Wiki. We provide comprehensive, up-to-date information to help you find solutions quickly.