PHP http_response_code Function

last modified April 4, 2025

The PHP http_response_code function gets or sets the HTTP response status code. It's essential for proper HTTP communication.

Basic Definition

http_response_code sets or retrieves the HTTP response code. It sends proper headers to the client when setting a new status code.

Syntax: http_response_code(int $response_code = null): int|bool. Returns current code if no parameter, or true/false when setting a code.

Setting a 404 Not Found Response

This example demonstrates setting a 404 status for missing resources.

not_found.php

<?php

declare(strict_types=1);

http_response_code(404);
echo "The requested resource was not found";
exit;

This sets the proper 404 status before outputting content. Browsers and crawlers understand this means the resource doesn't exist. Always exit after setting error codes to prevent further execution.

Getting Current Response Code

This shows how to retrieve the current HTTP response status code.

get_code.php

<?php

declare(strict_types=1);

$code = http_response_code();
echo "Current HTTP response code: $code";

When called without parameters, it returns the current status code. Default is 200 if no code was set. Useful for debugging and logging.

API Error Response

This example shows proper error handling in a JSON API response.

api_error.php

<?php

declare(strict_types=1);

header('Content-Type: application/json');
http_response_code(400);

echo json_encode([
    'error' => true,
    'message' => 'Invalid request parameters'
]);
exit;

APIs should use proper HTTP codes with error messages. This sets 400 (Bad Request) with a JSON error payload. Always set content-type header for APIs.

Redirect with 301 Status

This demonstrates a permanent redirect using HTTP 301 status code.

redirect.php

<?php

declare(strict_types=1);

http_response_code(301);
header('Location: https://new.example.com/page');
exit;

301 redirects tell browsers and search engines the move is permanent. Must include Location header. Always exit after redirect headers.

Custom Maintenance Page

This example shows a maintenance page with 503 Service Unavailable status.

maintenance.php

<?php

declare(strict_types=1);

http_response_code(503);
header('Retry-After: 3600'); // 1 hour
?>
<!DOCTYPE html>
<html>
<head>
    <title>Maintenance</title>
</head>
<body>
    <h1>Down for Maintenance</h1>
    <p>We'll be back soon!</p>
</body>
</html>

503 indicates temporary unavailability. Retry-After suggests when to check back. Useful for planned maintenance windows. Can include HTML content.

Best Practices

Early Execution: Set status codes before any output
Termination: Consider exiting after error codes
Validation: Use standard HTTP status codes
Headers: Combine with other relevant headers
Documentation: Document expected codes in APIs

Source

PHP http_response_code Documentation

This tutorial covered the PHP http_response_code function with practical examples for web development and API responses.

Author

My name is Jan Bodnar, and I am a passionate programmer with extensive programming experience. I have been writing programming articles since 2007. To date, I have authored over 1,400 articles and 8 e-books. I possess more than ten years of experience in teaching programming.

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