我知道这有点晚了，但答案很旧，我想我的基准测试可能会有帮助，因为我刚刚在PHP 7.4中测试过

Serialize/Unserialize比JSON快得多，占用的内存和空间更少，在PHP 7.4中完全胜出，但我不确定我的测试是最有效或最好的。

我基本上创建了一个PHP文件，它返回一个数组，我编码，序列化，然后解码和反序列化。

$array = include __DIR__.'/../tests/data/dao/testfiles/testArray.php';

//JSON ENCODE
$json_encode_memory_start = memory_get_usage();
$json_encode_time_start = microtime(true);

for ($i=0; $i < 20000; $i++) { 
    $encoded = json_encode($array);
}

$json_encode_time_end = microtime(true);
$json_encode_memory_end = memory_get_usage();
$json_encode_time = $json_encode_time_end - $json_encode_time_start;
$json_encode_memory = 
$json_encode_memory_end - $json_encode_memory_start;


//SERIALIZE
$serialize_memory_start = memory_get_usage();
$serialize_time_start = microtime(true);

for ($i=0; $i < 20000; $i++) { 
    $serialized = serialize($array);
}

$serialize_time_end = microtime(true);
$serialize_memory_end = memory_get_usage();
$serialize_time = $serialize_time_end - $serialize_time_start;
$serialize_memory = $serialize_memory_end - $serialize_memory_start;


//Write to file time:
$fpc_memory_start = memory_get_usage();
$fpc_time_start = microtime(true);

for ($i=0; $i < 20000; $i++) { 
    $fpc_bytes = 
    file_put_contents(
        __DIR__.'/../tests/data/dao/testOneBigFile',
        '<?php return '.var_export($array,true).' ?>;'
    );
}

$fpc_time_end = microtime(true);
$fpc_memory_end = memory_get_usage();
$fpc_time = $fpc_time_end - $fpc_time_start;
$fpc_memory = $fpc_memory_end - $fpc_memory_start;


//JSON DECODE
$json_decode_memory_start = memory_get_usage();
$json_decode_time_start = microtime(true);

for ($i=0; $i < 20000; $i++) { 
    $decoded = json_encode($encoded);
}

$json_decode_time_end = microtime(true);
$json_decode_memory_end = memory_get_usage();
$json_decode_time = $json_decode_time_end - $json_decode_time_start;
$json_decode_memory = 
$json_decode_memory_end - $json_decode_memory_start;


//UNSERIALIZE
$unserialize_memory_start = memory_get_usage();
$unserialize_time_start = microtime(true);

for ($i=0; $i < 20000; $i++) { 
    $unserialized = unserialize($serialized);
}

$unserialize_time_end = microtime(true);
$unserialize_memory_end = memory_get_usage();
$unserialize_time = $unserialize_time_end - $unserialize_time_start;
$unserialize_memory = 
$unserialize_memory_end - $unserialize_memory_start;


//GET FROM VAR EXPORT:
$var_export_memory_start = memory_get_usage();
$var_export_time_start = microtime(true);

for ($i=0; $i < 20000; $i++) { 
    $array = include __DIR__.'/../tests/data/dao/testOneBigFile';
}

$var_export_time_end = microtime(true);
$var_export_memory_end = memory_get_usage();
$var_export_time = $var_export_time_end - $var_export_time_start;
$var_export_memory = $var_export_memory_end - $var_export_memory_start;

结果:

Var输出长度:11447 序列化长度:11541 Json编码长度:11895 文件放内容字节:11464

Json编码时间:1.9197590351105 序列化时间:0.160325050354 FPC时间:6.2793469429016

Json编码内存:12288 序列化内存:12288 FPC内存:0

JSON解码时间:1.7493588924408 UnSerialize Time: 0.19309520721436 Var导出和包括:3.1974139213562

JSON解码内存:16384 反序列化内存:14360 Var Export and Include: 192

Y刚刚测试了serialized和json的encode和decode，加上它将把字符串存储的大小。

JSON encoded in 0.067085981369 seconds. Size (1277772)
PHP serialized in 0.12110209465 seconds. Size (1955548)
JSON decode in 0.22470498085 seconds
PHP serialized in 0.211947917938 seconds
json_encode() was roughly 80.52% faster than serialize()
unserialize() was roughly 6.02% faster than json_decode()
JSON string was roughly 53.04% smaller than Serialized string

我们可以得出结论，JSON编码更快，结果字符串更小，但unserialize解码字符串更快。

如果总结一下人们在这里所说的话，json_decode/encode似乎比序列化/反序列化BUT更快 如果执行var_dump，序列化对象的类型将被更改。 如果出于某种原因想要保留类型，请使用serialize!

(例如stdClass vs array)

序列化/非系列化:

Array cache:
array (size=2)
  'a' => string '1' (length=1)
  'b' => int 2
Object cache:
object(stdClass)[8]
  public 'field1' => int 123
This cache:
object(Controller\Test)[8]
  protected 'view' => 

JSON 编码/解码

Array cache:
object(stdClass)[7]
  public 'a' => string '1' (length=1)
  public 'b' => int 2
Object cache:
object(stdClass)[8]
  public 'field1' => int 123
This cache:
object(stdClass)[8]

正如你所看到的json_encode/decode将所有转换为stdClass，这不是很好，对象信息丢失…所以根据需要来决定，特别是如果它不仅仅是数组……

JSON比PHP的序列化格式更简单、更快，除非:

你正在存储深度嵌套数组: json_decode(): "如果JSON编码的数据大于127个元素，此函数将返回false。" 您存储的对象需要被反序列化为正确的类 您正在与不支持json_decode的旧PHP版本进行交互

我已经在一个相当复杂、嵌套简单、包含各种数据(字符串、NULL、整数)的多散列上对此进行了非常彻底的测试，序列化/反序列化最终比json_encode/json_decode快得多。

在我的测试中，json的唯一优势是它的“打包”大小更小。

这些都是在PHP 5.3.3下完成的，如果你想了解更多细节，请告诉我。

下面是测试结果，然后是生成它们的代码。我不能提供测试数据，因为它会泄露一些我不能公开的信息。

JSON encoded in 2.23700618744 seconds
PHP serialized in 1.3434419632 seconds
JSON decoded in 4.0405561924 seconds
PHP unserialized in 1.39393305779 seconds

serialized size : 14549
json_encode size : 11520
serialize() was roughly 66.51% faster than json_encode()
unserialize() was roughly 189.87% faster than json_decode()
json_encode() string was roughly 26.29% smaller than serialize()

//  Time json encoding
$start = microtime( true );
for($i = 0; $i < 10000; $i++) {
    json_encode( $test );
}
$jsonTime = microtime( true ) - $start;
echo "JSON encoded in $jsonTime seconds<br>";

//  Time serialization
$start = microtime( true );
for($i = 0; $i < 10000; $i++) {
    serialize( $test );
}
$serializeTime = microtime( true ) - $start;
echo "PHP serialized in $serializeTime seconds<br>";

//  Time json decoding
$test2 = json_encode( $test );
$start = microtime( true );
for($i = 0; $i < 10000; $i++) {
    json_decode( $test2 );
}
$jsonDecodeTime = microtime( true ) - $start;
echo "JSON decoded in $jsonDecodeTime seconds<br>";

//  Time deserialization
$test2 = serialize( $test );
$start = microtime( true );
for($i = 0; $i < 10000; $i++) {
    unserialize( $test2 );
}
$unserializeTime = microtime( true ) - $start;
echo "PHP unserialized in $unserializeTime seconds<br>";

$jsonSize = strlen(json_encode( $test ));
$phpSize = strlen(serialize( $test ));

echo "<p>serialized size : " . strlen(serialize( $test )) . "<br>";
echo "json_encode size : " . strlen(json_encode( $test )) . "<br></p>";

//  Compare them
if ( $jsonTime < $serializeTime )
{
    echo "json_encode() was roughly " . number_format( ($serializeTime / $jsonTime - 1 ) * 100, 2 ) . "% faster than serialize()";
}
else if ( $serializeTime < $jsonTime )
{
    echo "serialize() was roughly " . number_format( ($jsonTime / $serializeTime - 1 ) * 100, 2 ) . "% faster than json_encode()";
} else {
    echo 'Unpossible!';
}
    echo '<BR>';

//  Compare them
if ( $jsonDecodeTime < $unserializeTime )
{
    echo "json_decode() was roughly " . number_format( ($unserializeTime / $jsonDecodeTime - 1 ) * 100, 2 ) . "% faster than unserialize()";
}
else if ( $unserializeTime < $jsonDecodeTime )
{
    echo "unserialize() was roughly " . number_format( ($jsonDecodeTime / $unserializeTime - 1 ) * 100, 2 ) . "% faster than json_decode()";
} else {
    echo 'Unpossible!';
}
    echo '<BR>';
//  Compare them
if ( $jsonSize < $phpSize )
{
    echo "json_encode() string was roughly " . number_format( ($phpSize / $jsonSize - 1 ) * 100, 2 ) . "% smaller than serialize()";
}
else if ( $phpSize < $jsonSize )
{
    echo "serialize() string was roughly " . number_format( ($jsonSize / $phpSize - 1 ) * 100, 2 ) . "% smaller than json_encode()";
} else {
    echo 'Unpossible!';
}

这取决于你的优先级。

如果性能是你的绝对驾驶特点，那么无论如何要用最快的。在你做出选择之前，一定要充分了解它们之间的差异

Unlike serialize() you need to add extra parameter to keep UTF-8 characters untouched: json_encode($array, JSON_UNESCAPED_UNICODE) (otherwise it converts UTF-8 characters to Unicode escape sequences). JSON will have no memory of what the object's original class was (they are always restored as instances of stdClass). You can't leverage __sleep() and __wakeup() with JSON By default, only public properties are serialized with JSON. (in PHP>=5.4 you can implement JsonSerializable to change this behavior). JSON is more portable

可能还有其他一些不同之处，我现在想不出来。

一个简单的速度测试来比较两者

<?php

ini_set('display_errors', 1);
error_reporting(E_ALL);

// Make a big, honkin test array
// You may need to adjust this depth to avoid memory limit errors
$testArray = fillArray(0, 5);

// Time json encoding
$start = microtime(true);
json_encode($testArray);
$jsonTime = microtime(true) - $start;
echo "JSON encoded in $jsonTime seconds\n";

// Time serialization
$start = microtime(true);
serialize($testArray);
$serializeTime = microtime(true) - $start;
echo "PHP serialized in $serializeTime seconds\n";

// Compare them
if ($jsonTime < $serializeTime) {
    printf("json_encode() was roughly %01.2f%% faster than serialize()\n", ($serializeTime / $jsonTime - 1) * 100);
}
else if ($serializeTime < $jsonTime ) {
    printf("serialize() was roughly %01.2f%% faster than json_encode()\n", ($jsonTime / $serializeTime - 1) * 100);
} else {
    echo "Impossible!\n";
}

function fillArray( $depth, $max ) {
    static $seed;
    if (is_null($seed)) {
        $seed = array('a', 2, 'c', 4, 'e', 6, 'g', 8, 'i', 10);
    }
    if ($depth < $max) {
        $node = array();
        foreach ($seed as $key) {
            $node[$key] = fillArray($depth + 1, $max);
        }
        return $node;
    }
    return 'empty';
}