3v4l.org

run code in 300+ PHP versions simultaneously
<?php $n =0; for($i=0;$i<10;$i++){ echo $i.$i; }
Output for 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.27, 8.2.0 - 8.2.17, 8.3.0 - 8.3.4
00112233445566778899

preferences:
133.74 ms | 402 KiB | 150 Q