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 (!$var)1 ms>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms1 ms552
if (empty($var))>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms100
if ($var == '')1 ms>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms1 ms532
if ('' == $var)1 ms>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms1 ms612
if ($var === '')1 ms>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms1 ms480
if ('' === $var)>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms1 ms475
if (strcmp($var, '') == 0)1 ms>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms2 ms1071
if (strcmp('', $var) == 0)1 ms>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms1 ms970
if (strlen($var) == 0)>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms1 ms361
if (!strlen($var))>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms1 ms339

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($array) === 0 //by reference>0 ms>0 ms>0 ms226
count($array) === 0 //by value>0 ms>0 ms>0 ms183
$array === []>0 ms>0 ms>0 ms100
empty($array)>0 ms>0 ms>0 ms103
(bool)$array>0 ms>0 ms>0 ms216

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 ms245
$a === $b>0 ms>0 ms>0 ms>0 ms100
!strcmp($a, $b)1 ms1 ms1 ms2 ms1489
strcmp($a, $b) == 01 ms1 ms1 ms2 ms1534
strcmp($a, $b) === 01 ms1 ms1 ms2 ms1506
strcasecmp($a, $b) === 01 ms1 ms1 ms3 ms1808

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, $needle)>0 ms>0 ms>0 ms>0 ms>0 ms163
strpos($haystack, $needle) !== false>0 ms>0 ms>0 ms>0 ms>0 ms100
strstr($haystack, $needle) !== false>0 ms>0 ms>0 ms>0 ms>0 ms223
stristr($haystack, $needle)2 ms3 ms3 ms3 ms10 ms6255
preg_match("/$needle/", $haystack)>0 ms>0 ms>0 ms>0 ms1 ms464
preg_match("/$needle/i", $haystack)>0 ms>0 ms>0 ms>0 ms1 ms492
preg_match("/$needle/S", $haystack)>0 ms>0 ms>0 ms>0 ms1 ms390

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
$haystack[0] === 'n'>0 ms>0 ms>0 ms>0 ms>0 ms100
strncmp($haystack, $needle, strlen($needle)) === 0>0 ms>0 ms>0 ms>0 ms>0 ms331
strncmp($haystack, 'needle', 6) === 0>0 ms>0 ms>0 ms>0 ms>0 ms603
strncasecmp($haystack, $needle, strlen($needle)) === 0>0 ms>0 ms>0 ms>0 ms>0 ms315
strpos($haystack, $needle) === 0>0 ms>0 ms>0 ms>0 ms>0 ms547
substr($haystack, 0, strlen($needle)) === $needle>0 ms>0 ms>0 ms>0 ms>0 ms313
strcmp(substr($haystack, 0, strlen($needle)), $needle) === 0>0 ms>0 ms>0 ms>0 ms>0 ms585
substr_compare($haystack, $needle, 0, strlen($needle))>0 ms>0 ms>0 ms>0 ms>0 ms366
substr_compare($haystack, $needle, 0)>0 ms>0 ms>0 ms>0 ms>0 ms409
preg_match('/^' . preg_quote($needle, '/') . '/', $haystack)>0 ms>0 ms>0 ms>0 ms>0 ms1350

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 ms100
substr($haystack, strlen($haystack) - strlen($needle)) === $needle>0 ms>0 ms>0 ms>0 ms>0 ms229
substr($haystack, -strlen($needle)) === $needle>0 ms>0 ms>0 ms>0 ms>0 ms245
substr($haystack, -1) === 'n'>0 ms>0 ms>0 ms>0 ms>0 ms209
strcmp(substr($haystack, -strlen($needle)), $needle) === 0>0 ms>0 ms>0 ms>0 ms>0 ms497
substr_compare($haystack, $needle, -strlen($needle), strlen($needle))>0 ms>0 ms>0 ms>0 ms>0 ms299
substr_compare($haystack, $needle, -strlen($needle))>0 ms>0 ms>0 ms>0 ms>0 ms287
preg_match('/' . preg_quote($needle, '/') . '$/', $haystack)>0 ms>0 ms>0 ms>0 ms1 ms2086

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, $subject)>0 ms>0 ms>0 ms>0 ms>0 ms142
preg_replace("/$search/", $replace, $subject)>0 ms>0 ms>0 ms>0 ms>0 ms223
preg_replace("/$search/S", $replace, $subject)>0 ms>0 ms>0 ms>0 ms>0 ms220
strtr($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, $subject)>0 ms>0 ms>0 ms>0 ms1 ms100
strtr($subject, $fromChar, $toChar)1 ms3 ms2 ms1 ms7 ms1263
strtr($subject, array($fromChar => $toChar))>0 ms>0 ms>0 ms>0 ms1 ms113

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($string, ',')>0 ms>0 ms>0 ms>0 ms>0 ms100
preg_replace('/^,*|,*$/', '', $string)>0 ms>0 ms>0 ms>0 ms1 ms1135
preg_replace('/^,*|,*$/m', '', $string)2 ms2 ms2 ms2 ms7 ms8788
preg_replace('/^,+|,+$/', '', $string)>0 ms>0 ms>0 ms>0 ms>0 ms272
preg_replace('/^,+|,+$/m', '', $string)>0 ms>0 ms>0 ms>0 ms>0 ms206
preg_replace('/^,+/', '', preg_replace('/,+$/', '', …))>0 ms>0 ms>0 ms>0 ms>0 ms417

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 ms1 ms1 ms100
preg_split('/,/', $string)>0 ms>0 ms1 ms1 ms178
preg_match_all('/[^,]+/', $string, $matches)>0 ms>0 ms8 ms8 ms1005

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); $i++) //by reference>0 ms305
for ($i = 0; $i < count($array); $i++) //by value>0 ms195
for ($i = 0, $count = count($array); $i < $count; $i++)>0 ms100
for ($i = count($array) - 1; $i >= 0; $i--)>0 ms133
for ($i = count($array) - 1; $i >= 0; --$i)>0 ms119
$i = count($array); while ($i--)>0 ms148

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]3 ms111
$array['key']2 ms100

My conclusion: I like associative arrays.

Implode an Array

Method Summary Index
implode(' ', $array)1 ms1868
"$array[0] $array[1] $array[2]">0 ms100
$array[0] . ' ' . $array[1] . ' ' . $array[2]>0 ms118
sprintf('%s %s %s', $array[0], $array[1], $array[2])1 ms2286
vsprintf('%s %s %s', $array)2 ms2564

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 ms121
"contains no dollar signs">0 ms100
'$variables $are $not $replaced'>0 ms101
"\$variables \$are \$not \$replaced">0 ms104
"$variables $are $replaced">0 ms134
$variables . ' ' . $are . ' ' . $replaced>0 ms103
$variables . " " . $are . " " . $replaced>0 ms102

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 »