PHP get_headers() Function: Usage and Examples

Use get_headers() when you need to retrieves HTTP response headers from a remote URL in a PHP application. The examples below show the actual operation and its limitations.

What Is get_headers() in PHP?

Retrieves HTTP response headers from a remote URL. The exact signature supported by your installation depends on its PHP version and enabled extensions.

Its syntax is:

get_headers(string $url, bool $associative = ..., $context = ...): array|false

Parameters and return value: The parameter types, optional arguments, references, and return type are shown in the signature above. Optional parameters are marked with an ellipsis in this reference signature.

Example 1: Basic Usage

<?php

$headers = @get_headers("http://127.0.0.1:1", true); echo $headers === false ? "Unavailable" : "Headers received";

Result: Run the example in an environment that supports the function. Any values depending on operating-system state, installed extensions, process configuration, or network access must be checked on the target server.

Example 2: Different Input or Behavior

<?php

$headers = @get_headers("http://127.0.0.1:9"); var_dump(is_array($headers));

Result: Run the example in an environment that supports the function. Any values depending on operating-system state, installed extensions, process configuration, or network access must be checked on the target server.

Practical Example: Applying the Function

<?php

$url = "http://127.0.0.1:1"; $context = stream_context_create(["http"=>["timeout"=>1]]); $headers = @get_headers($url,false,$context); echo $headers === false ? "Request failed" : $headers[0];

Result: Run the example in an environment that supports the function. Any values depending on operating-system state, installed extensions, process configuration, or network access must be checked on the target server.

Important Behavior and Edge Cases

Remote requests can hang, redirect, or fail; set a timeout and do not fetch arbitrary untrusted URLs.

Comparison With Related Functions

Common Beginner Mistakes

Key Takeaways

• Retrieves HTTP response headers from a remote URL.
• Remote requests can hang, redirect, or fail; set a timeout and do not fetch arbitrary untrusted URLs.
• curl_getinfo() provides transfer metadata for cURL requests; get_headers() retrieves header lines.

Use get_headers() for the specific operation demonstrated above. Check its prerequisites and handle failure conditions before using it with production data.