PHP header_remove Function

last modified April 4, 2025

The PHP header_remove function removes previously set HTTP headers. It’s useful for modifying response headers before sending to clients.

Basic Definition

header_remove removes HTTP headers that were set with header(). It can remove specific headers or all headers if no name is provided.

Syntax: header_remove(?string $name = null): void. Returns nothing. Must be called before any output is sent to browser.

Removing a Specific Header

This example shows how to remove a specific HTTP header from the response.

remove_specific_header.php

<?php

declare(strict_types=1);

header(‘X-Powered-By: PHP/8.1’); header(‘X-Custom-Header: Test’);

// Remove only the X-Powered-By header header_remove(‘X-Powered-By’);

// Output remaining headers header(‘Content-Type: text/plain’); echo “Headers after removal:\n”; print_r(headers_list());

This code first sets two headers, then removes the X-Powered-By header. The remaining headers are displayed to show the removal was successful.

Removing All Headers

This demonstrates removing all previously set HTTP headers at once.

remove_all_headers.php

<?php

declare(strict_types=1);

header(‘X-Powered-By: PHP/8.1’); header(‘X-Custom-Header: Test’); header(‘Cache-Control: no-cache’);

// Remove all headers header_remove();

// Output remaining headers header(‘Content-Type: text/plain’); echo “Headers after removal:\n”; print_r(headers_list());

This example sets multiple headers then removes them all with one call. Only headers set after removal will appear in the final response.

Conditional Header Removal

This shows how to conditionally remove headers based on application logic.

conditional_removal.php

<?php

declare(strict_types=1);

$isProduction = false;

header(‘X-Debug-Info: Enabled’); header(‘X-Environment: Development’);

if ($isProduction) { header_remove(‘X-Debug-Info’); header_remove(‘X-Environment’); header(‘X-Environment: Production’); }

header(‘Content-Type: text/plain’); echo “Current headers:\n”; print_r(headers_list());

This removes debug headers in production while keeping them in development. Conditional removal helps maintain different header sets per environment.

Removing Content-Type Header

This example demonstrates removing and replacing the Content-Type header.

content_type_removal.php

<?php

declare(strict_types=1);

header(‘Content-Type: text/html’);

// Remove the existing Content-Type header_remove(‘Content-Type’);

// Set a new Content-Type header(‘Content-Type: application/json’);

echo json_encode([‘status’ => ‘success’, ‘message’ => ‘Content-Type changed’]);

This shows how to completely replace a header by first removing it. The Content-Type header is special as it affects how browsers interpret content.

Error Handling with Header Removal

This example shows proper error handling when working with header removal.

error_handling.php

<?php

declare(strict_types=1);

// Check if headers were already sent if (headers_sent()) { die(‘Cannot remove headers - output already started’); }

try { header(‘X-Test-Header: Value’); header_remove(‘X-Test-Header’);

if (in_array('X-Test-Header', array_map('strtolower', array_keys(headers_list())))) {
    throw new Exception('Header removal failed');
}

echo "Header successfully removed";

} catch (Exception $e) { error_log(“Header error: " . $e->getMessage()); echo “An error occurred while processing headers”; }

This demonstrates checking for headers_sent() and verifying removal success. Proper error handling ensures robust header manipulation in production.

Best Practices

• Timing: Call before any output to avoid headers_sent errors

• Case Sensitivity: Header names are case-insensitive

• Verification: Check headers_list() after removal

• Performance: Minimize header manipulation when possible

Source

PHP header_remove Documentation

This tutorial covered the PHP header_remove function with practical examples for HTTP header manipulation in various scenarios.

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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