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.
<?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.
<?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.
<?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.
<?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.
<?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.