422 Unprocessable Content

What This Error Means

The request was well-formed but contains semantic errors.

Request syntax is correct but semantically invalid.

Common Causes

• Invalid field values
• Business logic validation failure
• Required field missing
• Data type mismatch

How to Fix It (For Visitors)

• Check form inputs
• Verify required fields

How to Fix It (For Developers/Admins)

• Validate request data
• Check business rules
• Return detailed validation errors
• Verify data types and formats

Code Examples

Here's how to return a 422 status code in various programming languages:

Python (Flask)

from flask import Flask, jsonify

app = Flask(__name__)

@app.route('/endpoint')
def endpoint():
    return jsonify({"message": "Unprocessable Content"}), 422

Node.js (Express)

const express = require('express');
const app = express();

app.get('/endpoint', (req, res) => {
    res.status(422).json({ message: 'Unprocessable Content' });
});

PHP

<?php
http_response_code(422);
header('Content-Type: application/json');
echo json_encode(['message' => 'Unprocessable Content']);
?>

Go

package main

import (
    "encoding/json"
    "net/http"
)

func handler(w http.ResponseWriter, r *http.Request) {
    w.Header().Set("Content-Type", "application/json")
    w.WriteHeader(422)
    json.NewEncoder(w).Encode(map[string]string{
        "message": "Unprocessable Content",
    })
}

Java (Spring Boot)

@GetMapping("/endpoint")
public ResponseEntity<Map<String, String>> endpoint() {
    Map<String, String> response = new HashMap<>();
    response.put("message", "Unprocessable Content");
    return ResponseEntity.status(422).body(response);
}

Ruby (Sinatra)

get '/endpoint' do
    status 422
    json message: 'Unprocessable Content'
end

Browser Compatibility

Browser	Support	Notes
Chrome	✓ Full Support	All versions
Firefox	✓ Full Support	All versions
Safari	✓ Full Support	All versions
Edge	✓ Full Support	All versions

Official Specification

This status code is defined in RFC 4918.

View on IANA HTTP Status Code Registry →