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 (!$var)>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms1 ms445
if (empty($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 ms562
if ('' == $var)1 ms>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms1 ms714
if ($var === '')>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms1 ms467
if ('' === $var)>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms1 ms392
if (strcmp($var, '') == 0)1 ms>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms2 ms1173
if (strcmp('', $var) == 0)1 ms>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms2 ms1179
if (strlen($var) == 0)>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms1 ms467
if (!strlen($var))>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms>0 ms1 ms492

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($array) === 0 //by reference>0 ms>0 ms>0 ms215
count($array) === 0 //by value>0 ms>0 ms>0 ms157
$array === []>0 ms>0 ms>0 ms105
empty($array)>0 ms>0 ms>0 ms100
(bool)$array>0 ms>0 ms>0 ms181

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 ms216
$a === $b>0 ms>0 ms>0 ms>0 ms100
!strcmp($a, $b)1 ms1 ms1 ms2 ms1197
strcmp($a, $b) == 01 ms1 ms1 ms2 ms1354
strcmp($a, $b) === 01 ms1 ms1 ms2 ms1342
strcasecmp($a, $b) === 01 ms1 ms2 ms4 ms1989

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, $needle)>0 ms>0 ms>0 ms>0 ms>0 ms154
strpos($haystack, $needle) !== false>0 ms>0 ms>0 ms>0 ms>0 ms100
strstr($haystack, $needle) !== false>0 ms>0 ms>0 ms>0 ms>0 ms172
stristr($haystack, $needle)3 ms3 ms3 ms3 ms12 ms4778
preg_match("/$needle/", $haystack)>0 ms>0 ms>0 ms>0 ms1 ms438
preg_match("/$needle/i", $haystack)>0 ms>0 ms>0 ms>0 ms1 ms450
preg_match("/$needle/S", $haystack)>0 ms>0 ms>0 ms>0 ms1 ms455

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 ms209
strncmp($haystack, 'needle', 6) === 0>0 ms>0 ms>0 ms>0 ms>0 ms221
strncasecmp($haystack, $needle, strlen($needle)) === 0>0 ms>0 ms>0 ms>0 ms>0 ms190
strpos($haystack, $needle) === 0>0 ms>0 ms>0 ms>0 ms>0 ms374
substr($haystack, 0, strlen($needle)) === $needle>0 ms>0 ms>0 ms>0 ms>0 ms194
strcmp(substr($haystack, 0, strlen($needle)), $needle) === 0>0 ms>0 ms>0 ms>0 ms>0 ms357
substr_compare($haystack, $needle, 0, strlen($needle))>0 ms>0 ms>0 ms>0 ms>0 ms207
substr_compare($haystack, $needle, 0)>0 ms>0 ms>0 ms>0 ms>0 ms200
preg_match('/^' . preg_quote($needle, '/') . '/', $haystack)>0 ms>0 ms>0 ms>0 ms>0 ms708

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)) === $needle>0 ms>0 ms>0 ms>0 ms>0 ms204
substr($haystack, -strlen($needle)) === $needle>0 ms>0 ms>0 ms>0 ms>0 ms235
substr($haystack, -1) === 'n'>0 ms>0 ms>0 ms>0 ms>0 ms189
strcmp(substr($haystack, -strlen($needle)), $needle) === 0>0 ms>0 ms>0 ms>0 ms>0 ms337
substr_compare($haystack, $needle, -strlen($needle), strlen($needle))>0 ms>0 ms>0 ms>0 ms>0 ms233
substr_compare($haystack, $needle, -strlen($needle))>0 ms>0 ms>0 ms>0 ms>0 ms216
preg_match('/' . preg_quote($needle, '/') . '$/', $haystack)>0 ms>0 ms>0 ms>0 ms2 ms2572

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, $subject)>0 ms>0 ms>0 ms>0 ms>0 ms133
preg_replace("/$search/", $replace, $subject)>0 ms>0 ms>0 ms>0 ms1 ms235
preg_replace("/$search/S", $replace, $subject)>0 ms>0 ms>0 ms>0 ms1 ms216
strtr($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, $toChar)3 ms5 ms3 ms3 ms14 ms1224
strtr($subject, array($fromChar => $toChar))>0 ms>0 ms1 ms>0 ms1 ms105

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($string, ',')>0 ms>0 ms>0 ms>0 ms>0 ms100
preg_replace('/^,*|,*$/', '', $string)>0 ms>0 ms>0 ms>0 ms1 ms827
preg_replace('/^,*|,*$/m', '', $string)2 ms2 ms2 ms2 ms7 ms5077
preg_replace('/^,+|,+$/', '', $string)>0 ms>0 ms>0 ms>0 ms>0 ms161
preg_replace('/^,+|,+$/m', '', $string)>0 ms>0 ms>0 ms>0 ms>0 ms120
preg_replace('/^,+/', '', preg_replace('/,+$/', '', …))>0 ms>0 ms>0 ms>0 ms>0 ms260

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 ms2 ms208
preg_match_all('/[^,]+/', $string, $matches)>0 ms>0 ms2 ms2 ms298

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); $i++) //by reference>0 ms209
for ($i = 0; $i < count($array); $i++) //by value>0 ms189
for ($i = 0, $count = count($array); $i < $count; $i++)>0 ms100
for ($i = count($array) - 1; $i >= 0; $i--)>0 ms120
for ($i = count($array) - 1; $i >= 0; --$i)>0 ms116
$i = count($array); while ($i--)>0 ms138

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 ms101
$array['key']3 ms100

My conclusion: I like associative arrays.

Implode an Array

Method Summary Index
implode(' ', $array)1 ms2657
"$array[0] $array[1] $array[2]">0 ms106
$array[0] . ' ' . $array[1] . ' ' . $array[2]>0 ms100
sprintf('%s %s %s', $array[0], $array[1], $array[2])2 ms2987
vsprintf('%s %s %s', $array)2 ms3047

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 ms100
"contains no dollar signs">0 ms100
'$variables $are $not $replaced'>0 ms102
"\$variables \$are \$not \$replaced">0 ms124
"$variables $are $replaced">0 ms100
$variables . ' ' . $are . ' ' . $replaced>0 ms110
$variables . " " . $are . " " . $replaced>0 ms114

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
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