Postman向PHP发送POST请求失效问题咨询

Hey there, let's break down why your POST request isn't working in Postman while GET works perfectly. First, here's your code for reference:

<?php 
if(isset($_POST["test"])) echo $_POST["test"]; 
if(isset($_GET["test"])) echo $_GET["test"]; 
?>

Common Causes & Fixes #

• Postman Request Format Mismatch
  PHP's $_POST superglobal only parses data sent in form-encoded formats (like application/x-www-form-urlencoded or multipart/form-data). If you're sending raw JSON without setting the right headers, $_POST will be empty.

  • If you use form-data or x-www-form-urlencoded: Double-check that your parameter name is exactly test (case-sensitive!) and that you've added it correctly in the request body.
  • If you send raw JSON: You'll need to read the request body directly since PHP doesn't auto-parse JSON into $_POST. Modify your code like this:

    <?php
    // Handle JSON POST data
    $rawPost = file_get_contents('php://input');
    $postData = json_decode($rawPost, true);
    
    if(isset($postData["test"])) echo $postData["test"];
    if(isset($_GET["test"])) echo $_GET["test"];
    ?>
    

    And make sure to set Content-Type: application/json in Postman's Headers tab.

• PHP Configuration Issues

  • Check your php.ini file for post_max_size: If your POST request body exceeds this value, PHP will discard the data entirely, leaving $_POST empty. Increase it if needed (e.g., post_max_size = 8M).
  • Ensure enable_post_data_reading is set to On: This directive controls whether PHP reads POST data into $_POST—if it's off, $_POST will always be empty.

• Debug with Error Reporting
  Add error reporting to the top of your script to catch any hidden issues (like permission errors or configuration problems):

  <?php
  error_reporting(E_ALL);
  ini_set('display_errors', 1);
  
  if(isset($_POST["test"])) echo $_POST["test"]; 
  if(isset($_GET["test"])) echo $_GET["test"]; 
  ?>
  

  Also, replace your echo with var_dump($_POST); temporarily to see exactly what data PHP is receiving—this will tell you if the issue is missing data or a parameter name typo.

• Case Sensitivity Check
  Remember: PHP's superglobals are case-sensitive! If you accidentally sent Test instead of test in Postman, isset($_POST["test"]) will return false. Double-check your parameter spelling and capitalization.

内容的提问来源于stack exchange，提问作者Luis Miguel Molina Betancourt