My PHP Performance Benchmarks

PHP version 7.4.33 is running on this server. The benchmarks are done live. Reload the page to get fresh numbers. You are free to use the source for whatever you want. Giving credits to me (Thiemo Mättig) would be nice.

Please note that these are micro benchmarks. Micro benchmarks are stupid. I created this comparison to learn something about PHP and how the PHP compiler works. This can not be used to compare PHP versions or servers.

Check if a String is empty

Method Undefined Null False Empty string String '0' String '1' Long string Summary Index
if (!$var)6 ms>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms6 ms6675
if (empty($var))>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms100
if ($var == '')>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms1 ms630
if ('' == $var)>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms1 ms640
if ($var === '')>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms509
if ('' === $var)>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms514
if (strcmp($var, '') == 0)>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms1 ms826
if (strcmp('', $var) == 0)>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms1 ms847
if (strlen($var) == 0)>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms1 ms656
if (!strlen($var))>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms1 ms594

My conclusion: In most cases, Do not use empty() because it does not trigger a warning when used with undefined variables. Note that empty('0') returns true. Use strlen() if you want to detect '0'. Try to avoid == at all because it may cause strange behaviour (e.g. '9a' == 9 returns true). Prefer === over == and !== over != if possible because it does compare the variable types in addition to the contents.

Check if an Array is empty

Method Empty array 100 elements Summary Index
count($array) === 0 //by reference>0 ms>0 ms>0 ms188
count($array) === 0 //by value>0 ms>0 ms>0 ms358
$array === []>0 ms>0 ms>0 ms100
empty($array)>0 ms>0 ms>0 ms100
(bool)$array>0 ms>0 ms>0 ms195

My conclusion: Why count if you don't care about the exact number?

Compare two Strings

Method Equal First character not equal Last character not equal Summary Index
$a == $b>0 ms>0 ms>0 ms>0 ms265
$a === $b>0 ms>0 ms>0 ms>0 ms100
!strcmp($a, $b)>0 ms>0 ms>0 ms1 ms477
strcmp($a, $b) == 0>0 ms>0 ms>0 ms1 ms487
strcmp($a, $b) === 0>0 ms>0 ms>0 ms1 ms484
strcasecmp($a, $b) === 0>0 ms>0 ms1 ms1 ms949

My conclusion: Use what fits your needs.

Check if a String contains another String

Method Not found Found at the start Found in the middle Found at the end Summary Index
strstr($haystack, $needle)>0 ms>0 ms>0 ms>0 ms>0 ms207
strpos($haystack, $needle) !== false>0 ms>0 ms>0 ms>0 ms>0 ms100
strstr($haystack, $needle) !== false>0 ms>0 ms>0 ms>0 ms>0 ms169
stristr($haystack, $needle)2 ms2 ms2 ms2 ms8 ms7247
preg_match("/$needle/", $haystack)>0 ms>0 ms>0 ms>0 ms1 ms950
preg_match("/$needle/i", $haystack)>0 ms>0 ms>0 ms>0 ms1 ms1096
preg_match("/$needle/S", $haystack)>0 ms>0 ms>0 ms>0 ms1 ms921

My conclusion: It does not matter if you use strstr() or strpos(). Use the preg…() functions only if you need the power of regular expressions. Never use the ereg…() functions.

Check if a String starts with another String

Method Not found Found at the start Found in the middle Found at the end Summary Index
$haystack[0] === 'n'>0 ms>0 ms>0 ms>0 ms>0 ms115
strncmp($haystack, $needle, strlen($needle)) === 0>0 ms>0 ms>0 ms>0 ms>0 ms119
strncmp($haystack, 'needle', 6) === 0>0 ms>0 ms>0 ms>0 ms>0 ms100
strncasecmp($haystack, $needle, strlen($needle)) === 0>0 ms>0 ms>0 ms>0 ms>0 ms100
strpos($haystack, $needle) === 0>0 ms>0 ms>0 ms>0 ms>0 ms217
substr($haystack, 0, strlen($needle)) === $needle>0 ms>0 ms>0 ms>0 ms>0 ms160
strcmp(substr($haystack, 0, strlen($needle)), $needle) === 0>0 ms>0 ms>0 ms>0 ms>0 ms155
substr_compare($haystack, $needle, 0, strlen($needle))>0 ms>0 ms>0 ms>0 ms>0 ms128
substr_compare($haystack, $needle, 0)>0 ms>0 ms>0 ms>0 ms>0 ms105
preg_match('/^' . preg_quote($needle, '/') . '/', $haystack)>0 ms>0 ms>0 ms>0 ms>0 ms441

My conclusion: strpos() is very fast and can be used in almost all cases. strncmp() is good if you are looking for a constant length needle.

Check if a String ends with another String

Method Not found Found at the start Found in the middle Found at the end Summary Index
$haystack[strlen($haystack) - 1] === 'n'>0 ms>0 ms>0 ms>0 ms>0 ms162
substr($haystack, strlen($haystack) - strlen($needle)) === $needle>0 ms>0 ms>0 ms>0 ms>0 ms144
substr($haystack, -strlen($needle)) === $needle>0 ms>0 ms>0 ms>0 ms>0 ms126
substr($haystack, -1) === 'n'>0 ms>0 ms>0 ms>0 ms>0 ms100
strcmp(substr($haystack, -strlen($needle)), $needle) === 0>0 ms>0 ms>0 ms>0 ms>0 ms232
substr_compare($haystack, $needle, -strlen($needle), strlen($needle))>0 ms>0 ms>0 ms>0 ms>0 ms222
substr_compare($haystack, $needle, -strlen($needle))>0 ms>0 ms>0 ms>0 ms>0 ms221
preg_match('/' . preg_quote($needle, '/') . '$/', $haystack)>0 ms>0 ms>0 ms>0 ms1 ms5026

My conclusion: Using substr() with a negative position is a good trick.

Replace a (>1 Character) String inside another String

Method Not found Found at the start Found in the middle Found at the end Summary Index
str_replace($search, $replace, $subject)>0 ms>0 ms>0 ms>0 ms>0 ms135
preg_replace("/$search/", $replace, $subject)>0 ms>0 ms>0 ms>0 ms>0 ms263
preg_replace("/$search/S", $replace, $subject)>0 ms>0 ms>0 ms>0 ms>0 ms255
strtr($subject, array($search => $replace))>0 ms>0 ms>0 ms>0 ms>0 ms100

My conclusion: Never use the ereg…() functions.

Replace a Character inside a String

Method Not found Found at the start Found in the middle Found at the end Summary Index
str_replace($fromChar, $toChar, $subject)>0 ms>0 ms>0 ms>0 ms>0 ms124
strtr($subject, $fromChar, $toChar)1 ms7 ms2 ms1 ms11 ms3124
strtr($subject, array($fromChar => $toChar))>0 ms>0 ms>0 ms>0 ms>0 ms100

My conclusion: Since PHP 7.0 strtr() can sometimes beat str_replace().

Trim Characters from the Beginning and End of a String

Method Not found Found at start Found at end Found at both sides Summary Index
trim($string, ',')>0 ms>0 ms>0 ms>0 ms>0 ms100
preg_replace('/^,*|,*$/', '', $string)>0 ms>0 ms>0 ms>0 ms1 ms3848
preg_replace('/^,*|,*$/m', '', $string)1 ms1 ms1 ms1 ms5 ms24457
preg_replace('/^,+|,+$/', '', $string)>0 ms>0 ms>0 ms>0 ms>0 ms537
preg_replace('/^,+|,+$/m', '', $string)>0 ms>0 ms>0 ms>0 ms>0 ms414
preg_replace('/^,+/', '', preg_replace('/,+$/', '', …))>0 ms>0 ms>0 ms>0 ms>0 ms585

My conclusion: Always benchmark your regular expressions! In this case, with .* you also replace nothing with nothing which takes time because there is a lot of “nothing” in every string.

Split a String into an Array

Method Empty string Single occurrence Multiple occurrences Summary Index
explode(',', $string)>0 ms>0 ms>0 ms1 ms100
preg_split('/,/', $string)>0 ms>0 ms1 ms1 ms180
preg_match_all('/[^,]+/', $string, $matches)>0 ms>0 ms1 ms2 ms281

My conclusion: Don't use split(). It got deprecated in PHP 5.3 and removed from PHP 7.0.

Loop a numerical indexed Array of Strings

Method Summary Index
for ($i = 0; $i < count($array); $i++) //by reference>0 ms234
for ($i = 0; $i < count($array); $i++) //by value>0 ms200
for ($i = 0, $count = count($array); $i < $count; $i++)>0 ms100
for ($i = count($array) - 1; $i >= 0; $i--)>0 ms124
for ($i = count($array) - 1; $i >= 0; --$i)>0 ms130
$i = count($array); while ($i--)>0 ms150

My conclusion: count() could have been horribly slow in PHP 5 and below when copy-on-write accidentally kicked in. Always precalculate it, if possible.

Get Elements from an Array

Method Summary Index
$array[0]2 ms101
$array['key']2 ms100

My conclusion: I like associative arrays.

Implode an Array

Method Summary Index
implode(' ', $array)>0 ms100
"$array[0] $array[1] $array[2]">0 ms107
$array[0] . ' ' . $array[1] . ' ' . $array[2]>0 ms104
sprintf('%s %s %s', $array[0], $array[1], $array[2])1 ms2093
vsprintf('%s %s %s', $array)1 ms2219

My conclusion: String concatenation is a cheap operation in PHP. Don't waste your time benchmarking this.

The single vs. double Quotes Myth

Method Summary Index
'contains no dollar signs'>0 ms102
"contains no dollar signs">0 ms102
'$variables $are $not $replaced'>0 ms101
"\$variables \$are \$not \$replaced">0 ms114
"$variables $are $replaced">0 ms103
$variables . ' ' . $are . ' ' . $replaced>0 ms100
$variables . " " . $are . " " . $replaced>0 ms100

My conclusion: It does not matter if you use single or double quotes at all. The inclusion of variables has a measurable effect, but that's independent from the quotes.

© Thiemo Mättig, created in September 2008, updated in August 2017
More PHP experiments »