JSON in PHP: Complete Guide

json_decode and json_encode

PHP has built-in JSON functions available since PHP 5.2:

<?php
$json = '{"name": "Alice", "age": 30}';

// Decode to object
$obj = json_decode($json);
echo $obj->name; // Alice

// Decode to associative array
$arr = json_decode($json, true);
echo $arr['name']; // Alice

// Encode PHP to JSON
$data = ['name' => 'Bob', 'scores' => [95, 87]];
echo json_encode($data);
// {"name":"Bob","scores":[95,87]}
?>

json_encode Options

<?php
// Pretty print + unescaped slashes
echo json_encode($data, JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE);

// Throw exception on error (PHP 7.3+)
echo json_encode($data, JSON_THROW_ON_ERROR);
?>

Error Handling (PHP 7.3+)

<?php
try {
    $result = json_decode($json, true, 512, JSON_THROW_ON_ERROR);
} catch (JsonException $e) {
    echo 'JSON error: ' . $e->getMessage();
}
?>

JSON API Response in PHP

<?php
header('Content-Type: application/json');
$users = [['id' => 1, 'name' => 'Alice']];
echo json_encode(['data' => $users, 'meta' => ['total' => 1]], JSON_PRETTY_PRINT);
?>

Common json_encode Pitfalls

FAQ