Redirection (3xx)

HTTP 304304 Not Modified

Indicates that the resource has not been modified since the version specified by the request headers If-Modified-Since or If-None-Match.

Common Causes & Diagnoses
  • Browser sends ETag or If-Modified-Since and server verifies content is unchanged.
Spesifikasyon & Kategori
Status Code:304
Category:Redirection (3xx)
RFC Standard:RFC 9110 / HTTP/1.1 & HTTP/2
Multi-Language Code Implementations

How to Handle, Return & Test HTTP 304

Status: 304 304 Not Modified
server.js / handler.ts
// Express.js Server Response
app.get('/api/resource', (req, res) => {
  return res.status(304).json({ success: true, status: 304 });
});

// Client-side fetch error check
const response = await fetch('/api/resource');
if (response.status === 304) {
  console.warn('Received HTTP 304 304 Not Modified');
}
💡 Pro Tip: Ensure appropriate error handling middleware or proxy interceptors are enabled so client applications receive structured JSON responses for HTTP 304.
How to Fix / Practical Code Solutions

ETag Cache Hit

Return empty body with 304 status to save bandwidth.

Other Popular HTTP Status Codes
Frequently Asked Questions

Common Questions About HTTP 304 to RFC Standard

Everything you need to know regarding specifications, syntax, and security best practices.

Indicates that the resource has not been modified since the version specified by the request headers If-Modified-Since or If-None-Match. In Turkish: İstenen kaynak tarayıcının önbelleğindeki sürümden bu yana değişmedi.