3v4l.org

run code in 300+ PHP versions simultaneously
<?php $str = "racecar"; $pal = ""; for($a=0; $a<strlen($str); $a++) { for($z=0; $z<strlen($str); $z++) { $subs = substr($str, $a, $z); if( $subs == strrev($subs) and strlen($subs) > strlen($pal) ) { $pal = $subs; } } } echo $pal;

Here you find the average performance (time & memory) of each version. A grayed out version indicates it didn't complete successfully (based on exit-code).

VersionSystem time (s)User time (s)Memory (MiB)
8.3.60.0120.00916.75
8.3.50.0090.01316.40
8.3.40.0080.00818.44
8.3.30.0110.00318.55
8.3.20.0090.00018.48
8.3.10.0000.00920.48
8.3.00.0050.00319.26
8.2.180.0080.00616.32
8.2.170.0110.00422.96
8.2.160.0090.00618.82
8.2.150.0080.00024.18
8.2.140.0050.00324.66
8.2.130.0070.00726.16
8.2.120.0060.00321.11
8.2.110.0030.00620.93
8.2.100.0030.00917.84
8.2.90.0060.00317.84
8.2.80.0040.00817.97
8.2.70.0000.00818.05
8.2.60.0050.00518.22
8.2.50.0040.00418.10
8.2.40.0040.00819.22
8.2.30.0040.00419.12
8.2.20.0060.00317.62
8.2.10.0030.00517.67
8.2.00.0000.00817.73
8.1.280.0100.01025.92
8.1.270.0060.01223.99
8.1.260.0040.01126.35
8.1.250.0000.00728.09
8.1.240.0030.00623.77
8.1.230.0080.00322.82
8.1.220.0030.00517.76
8.1.210.0030.00618.85
8.1.200.0000.00817.35
8.1.190.0030.00617.22
8.1.180.0050.00318.10
8.1.170.0000.00818.40
8.1.160.0070.00018.92
8.1.150.0040.00418.82
8.1.140.0040.00417.43
8.1.130.0000.00717.86
8.1.120.0070.00017.47
8.1.110.0000.00917.36
8.1.100.0040.00417.41
8.1.90.0000.00817.34
8.1.80.0030.00317.44
8.1.70.0000.00617.41
8.1.60.0000.00917.54
8.1.50.0050.00317.32
8.1.40.0000.00817.50
8.1.30.0060.00317.57
8.1.20.0000.00817.70
8.1.10.0030.00517.52
8.1.00.0070.00017.45
8.0.300.0040.00419.68
8.0.290.0040.00416.75
8.0.280.0000.00718.30
8.0.270.0040.00417.29
8.0.260.0060.00016.72
8.0.250.0030.00316.89
8.0.240.0090.00016.98
8.0.230.0030.00316.98
8.0.220.0070.00016.94
8.0.210.0050.00316.94
8.0.200.0060.00016.82
8.0.190.0040.00416.82
8.0.180.0070.00016.93
8.0.170.0080.00316.79
8.0.160.0040.00416.90
8.0.150.0030.00616.79
8.0.140.0110.00016.78
8.0.130.0030.00313.27
8.0.120.0030.00516.84
8.0.110.0040.00416.73
8.0.100.0000.00716.79
8.0.90.0000.00716.84
8.0.80.0000.01516.79
8.0.70.0000.00816.92
8.0.60.0000.00816.77
8.0.50.0030.00316.91
8.0.30.0100.01017.30
8.0.20.0120.00717.23
8.0.10.0070.00017.07
8.0.00.0140.00816.67
7.4.330.0000.00612.97
7.4.320.0030.00316.50
7.4.300.0000.00716.47
7.4.290.0000.00716.54
7.4.280.0030.00316.50
7.4.270.0030.00316.40
7.4.260.0000.00613.26
7.4.250.0080.00016.53
7.4.240.0000.00716.52
7.4.230.0000.00716.61
7.4.220.0120.01016.61
7.4.210.0090.01216.67
7.4.200.0000.00716.57
7.4.190.0060.00016.44
7.4.160.0090.00616.30
7.4.150.0110.00816.36
7.4.140.0070.01016.38
7.4.130.0030.01416.53
7.4.120.0120.00616.65
7.4.110.0060.01216.57
7.4.100.0070.01016.51
7.4.90.0110.00716.49
7.4.80.0120.00619.39
7.4.70.0130.00316.30
7.4.60.0160.00316.46
7.4.50.0050.00016.19
7.4.40.0070.00716.45
7.4.30.0090.00616.61
7.4.00.0040.01014.68
7.3.330.0000.00713.07
7.3.320.0080.00013.14
7.3.310.0070.00016.42
7.3.300.0070.00016.36
7.3.290.0090.00616.37
7.3.280.0070.00916.36
7.3.270.0060.01216.57
7.3.260.0070.01016.44
7.3.250.0100.00716.43
7.3.240.0090.01216.36
7.3.230.0070.01016.57
7.3.210.0140.00316.44
7.3.200.0030.01716.48
7.3.190.0070.01016.32
7.3.180.0100.00616.38
7.3.170.0100.01116.38
7.3.160.0090.00616.37
7.3.120.0080.00814.99
7.3.110.0030.01614.75
7.3.100.0060.01314.85
7.3.90.0070.00714.59
7.3.80.0060.00914.84
7.3.70.0100.00714.78
7.3.60.0030.00614.80
7.3.50.0000.01414.72
7.3.40.0060.00914.67
7.3.30.0060.00514.29
7.3.20.0070.00716.66
7.3.10.0040.01216.49
7.3.00.0080.00416.73
7.2.330.0060.01216.61
7.2.320.0100.01416.68
7.2.310.0110.00716.57
7.2.300.0030.01316.61
7.2.290.0080.00816.76
7.2.250.0090.00915.01
7.2.240.0060.01014.90
7.2.230.0030.01314.90
7.2.220.0040.01115.22
7.2.210.0070.01014.69
7.2.200.0040.01114.98
7.2.190.0000.01514.94
7.2.180.0110.00715.04
7.2.170.0140.00314.87
7.2.160.0060.00614.97
7.2.150.0090.00616.75
7.2.140.0030.00816.98
7.2.130.0040.01216.81
7.2.120.0030.01216.62
7.2.110.0070.00716.91
7.2.100.0130.00016.89
7.2.90.0000.01216.72
7.2.80.0060.00916.87
7.2.70.0000.01916.87
7.2.60.0160.00916.95
7.2.50.0110.00516.81
7.2.40.0030.00916.89
7.2.30.0030.01416.66
7.2.20.0120.00016.84
7.2.10.0000.01216.84
7.2.00.0060.01018.23
7.1.330.0030.01415.82
7.1.320.0070.00715.79
7.1.310.0090.00916.10
7.1.300.0100.00315.45
7.1.290.0040.01115.63
7.1.280.0100.00315.86
7.1.270.0110.00315.73
7.1.260.0030.01415.73
7.1.250.0000.01415.57
7.1.240.0040.01115.83
7.1.230.0060.00315.50
7.1.220.0070.00715.73
7.1.210.0030.01015.86
7.1.200.0020.01115.80
7.1.190.0060.01015.59
7.1.180.0040.01215.69
7.1.170.0070.00415.51
7.1.160.0000.01215.76
7.1.150.0070.01015.91
7.1.140.0070.00315.74
7.1.130.0030.00815.60
7.1.120.0060.00315.72
7.1.110.0060.00615.91
7.1.100.0060.01215.89
7.1.90.0030.01215.70
7.1.80.0000.01415.63
7.1.70.0030.00616.59
7.1.60.0020.01116.60
7.1.50.0030.01516.25
7.1.40.0120.00315.60
7.1.30.0030.01315.48
7.1.20.0060.01015.69
7.1.10.0100.00315.70
7.1.00.0010.02319.03
7.0.330.0080.00815.40
7.0.320.0040.00815.08
7.0.310.0030.00715.53
7.0.300.0030.01015.38
7.0.290.0030.00915.48
7.0.280.0070.00715.45
7.0.270.0080.00415.43
7.0.260.0030.00615.22
7.0.250.0100.00615.53
7.0.240.0040.00415.48
7.0.230.0000.01115.43
7.0.220.0030.01015.40
7.0.210.0000.01415.00
7.0.200.0010.01216.13
7.0.190.0040.00715.44
7.0.180.0060.00915.40
7.0.170.0030.00715.34
7.0.160.0090.00315.32
7.0.150.0050.00515.38
7.0.140.0020.04418.85
7.0.130.0070.00415.41
7.0.120.0030.04118.69
7.0.110.0090.00315.39
7.0.100.0000.00815.11
7.0.90.0030.01215.49
7.0.80.0100.00315.55
7.0.70.0070.00715.26
7.0.60.0080.02017.50
7.0.50.0070.03416.59
7.0.40.0070.03716.77
7.0.30.0160.05116.74
7.0.20.0230.04016.93
7.0.10.0070.02416.72
7.0.00.0060.04516.83
5.6.400.0100.00714.21
5.6.390.0130.00314.44
5.6.380.0060.00614.28
5.6.370.0100.00314.18
5.6.360.0070.00314.46
5.6.350.0000.01114.48
5.6.340.0070.00414.36
5.6.330.0060.00614.00
5.6.320.0060.00614.15
5.6.310.0030.00914.20
5.6.300.0030.01013.74
5.6.290.0030.00613.86
5.6.280.0000.04417.56
5.6.270.0080.00414.31
5.6.260.0040.01214.20
5.6.250.0000.01114.05
5.6.240.0090.00014.27
5.6.230.0040.01113.96
5.6.220.0070.00714.34
5.6.210.0030.02717.45
5.6.200.0070.04316.10
5.6.190.0030.05217.41
5.6.180.0380.03017.31
5.6.170.0150.02517.45
5.6.160.0080.03517.15
5.6.150.0060.02316.32
5.6.140.0070.04216.19
5.6.130.0100.03616.13
5.6.120.0090.02317.76
5.6.110.0080.04817.55
5.6.100.0050.02717.61
5.6.90.0050.04917.73
5.6.80.0030.04617.24
5.6.70.0070.00414.31
5.6.60.0070.00714.19
5.6.50.0070.00314.15
5.6.40.0060.00614.04
5.6.30.0080.00314.24
5.6.20.0050.00514.17
5.6.10.0080.00013.87
5.6.00.0000.00814.38
5.5.380.0110.00414.40
5.5.370.0050.00914.03
5.5.360.0060.00913.98
5.5.350.0020.04717.41
5.5.340.0020.02716.19
5.5.330.0050.04917.27
5.5.320.0130.04517.11
5.5.310.0170.02017.36
5.5.300.0020.02715.92
5.5.290.0040.02816.06
5.5.280.0030.02517.46
5.5.270.0110.03017.39
5.5.260.0070.04717.55
5.5.250.0090.04617.49
5.5.240.0080.04117.13
5.5.230.0030.01314.14
5.5.220.0040.01214.03
5.5.210.0060.00314.11
5.5.200.0060.00613.99
5.5.190.0000.01213.88
5.5.180.0040.00713.93
5.5.170.0000.01114.06
5.5.160.0060.00613.89
5.5.150.0000.00914.14
5.5.140.0040.00713.85
5.5.130.0030.01014.11
5.5.120.0070.00614.18
5.5.110.0000.00914.23
5.5.100.0000.00814.09
5.5.90.0080.00414.11
5.5.80.0030.00713.77
5.5.70.0130.00013.96
5.5.60.0000.01414.18
5.5.50.0030.00714.09
5.5.40.0090.00313.83
5.5.30.0040.00814.12
5.5.20.0000.01614.06
5.5.10.0150.00013.97
5.5.00.0040.01113.84
5.4.450.0110.03815.21
5.4.440.0060.04015.27
5.4.430.0060.03815.13
5.4.420.0060.04315.15
5.4.410.0050.04315.07
5.4.400.0080.03714.96
5.4.390.0050.04315.00
5.4.380.0090.03814.96
5.4.370.0080.02014.87
5.4.360.0020.02915.03
5.4.350.0050.02315.08
5.4.340.0070.04314.80
5.4.330.0080.00010.90
5.4.320.0040.02714.77
5.4.310.0050.02514.98
5.4.300.0030.02514.83
5.4.290.0040.03914.90
5.4.280.0110.02414.94
5.4.270.0070.04214.72
5.4.260.0020.04215.05
5.4.250.0050.03014.79
5.4.240.0050.03915.03
5.4.230.0100.03714.90
5.4.220.0060.03114.91
5.4.210.0080.02714.98
5.4.200.0040.03414.98
5.4.190.0050.02214.98
5.4.180.0050.02314.89
5.4.170.0030.02714.88
5.4.160.0050.03514.78
5.4.150.0080.03314.96
5.4.140.0050.01913.73
5.4.130.0080.02813.62
5.4.120.0000.03313.75
5.4.110.0120.03513.68
5.4.100.0000.02913.48
5.4.90.0030.02013.62
5.4.80.0080.04013.62
5.4.70.0080.03713.71
5.4.60.0110.03513.53
5.4.50.0130.03313.67
5.4.40.0060.02313.47
5.4.30.0050.03913.68
5.4.20.0070.02813.49
5.4.10.0100.03813.57
5.4.00.0030.03913.27
5.3.290.0120.03712.45
5.3.280.0030.04412.46
5.3.270.0070.03012.57
5.3.260.0030.02512.53
5.3.250.0050.02712.35
5.3.240.0070.04012.42
5.3.230.0080.03812.53
5.3.220.0080.03712.47
5.3.210.0080.03012.38
5.3.200.0070.04012.31
5.3.190.0050.04112.47
5.3.180.0020.03512.54
5.3.170.0040.02812.49
5.3.160.0070.03812.51
5.3.150.0060.02112.46
5.3.140.0050.03812.47
5.3.130.0090.02112.39
5.3.120.0070.04312.47
5.3.110.0060.04112.40
5.3.100.0050.03312.06
5.3.90.0050.03812.21
5.3.80.0010.03512.13
5.3.70.0040.02812.05
5.3.60.0090.03812.16
5.3.50.0080.03612.11
5.3.40.0030.02512.09
5.3.30.0020.02712.16
5.3.20.0050.04012.03
5.3.10.0080.03511.80
5.3.00.0070.03511.92
5.2.170.0070.05311.02
5.2.160.0030.06311.05
5.2.150.0000.06011.07
5.2.140.0030.05711.02
5.2.130.0030.06011.04
5.2.120.0070.04311.07
5.2.110.0070.06311.02
5.2.100.0070.05311.03
5.2.90.0000.05310.92
5.2.80.0000.03710.98
5.2.70.0030.06311.02
5.2.60.0030.06310.95
5.2.50.0000.07011.17
5.2.40.0100.03010.98
5.2.30.0030.07010.96
5.2.20.0070.05711.03
5.2.10.0030.05310.84
5.2.00.0070.05310.61
5.1.60.0070.0309.98
5.1.50.0000.0439.97
5.1.40.0070.0509.88
5.1.30.0100.04710.29
5.1.20.0030.04010.39
5.1.10.0030.05010.01
5.1.00.0170.04310.06
5.0.50.0030.0478.61
5.0.40.0070.0308.42
5.0.30.0130.0238.33
5.0.20.0000.0408.33
5.0.10.0000.0308.33
5.0.00.0100.0578.33
4.4.90.0000.0238.33
4.4.80.0070.0278.33
4.4.70.0000.0208.33
4.4.60.0070.0308.33
4.4.50.0000.0208.33
4.4.40.0070.0508.33
4.4.30.0000.0278.33
4.4.20.0030.0338.33
4.4.10.0000.0378.33
4.4.00.0000.0408.33
4.3.110.0030.0208.33
4.3.100.0100.0278.33
4.3.90.0030.0208.33
4.3.80.0000.0338.33
4.3.70.0000.0278.33
4.3.60.0030.0208.33
4.3.50.0030.0178.33
4.3.40.0030.0338.33
4.3.30.0000.0208.33
4.3.20.0000.0378.33
4.3.10.0000.0338.33
4.3.00.0030.0208.33

preferences:
45.79 ms | 401 KiB | 5 Q