Client Error (4xx)
HTTP 409 — 409 Conflict
Indicates that the request could not be processed because of conflict in the current state of the resource, such as an edit conflict between multiple concurrent updates.
Common Causes & Diagnoses
- •Unique constraint violation (duplicate username/email), git merge conflict.
Spesifikasyon & Kategori
Status Code:409
Category:Client Error (4xx)
RFC Standard:RFC 9110 / HTTP/1.1 & HTTP/2
Multi-Language Code Implementations
How to Handle, Return & Test HTTP 409
Status: 409 409 Conflict
server.js / handler.ts
// Express.js Server Response
app.get('/api/resource', (req, res) => {
// Returning 409 409 Conflict
return res.status(409).json({
error: '409 Conflict',
statusCode: 409,
timestamp: new Date().toISOString()
});
});
// Client-side fetch error check
const response = await fetch('/api/resource');
if (response.status === 409) {
console.warn('Received HTTP 409 409 Conflict');
}💡 Pro Tip: Ensure appropriate error handling middleware or proxy interceptors are enabled so client applications receive structured JSON responses for HTTP 409.
How to Fix / Practical Code Solutions
Handle Duplicate Key Error
Catch unique constraint error and return 409 with explanatory message.
Other Popular HTTP Status Codes
Frequently Asked Questions
Common Questions About HTTP 409 to RFC Standard
Everything you need to know regarding specifications, syntax, and security best practices.
Indicates that the request could not be processed because of conflict in the current state of the resource, such as an edit conflict between multiple concurrent updates. In Turkish: Kaynak durumunda çakışma oluştu (örn. veritabanında zaten kayıtlı benzersiz e-posta).