3v4l.org

run code in 300+ PHP versions simultaneously
<?php $arr=[ 'foo'=>"\xFF" ]; var_dump(json_encode($arr,JSON_PARTIAL_OUTPUT_ON_ERROR));
Output for 5.5.0 - 5.5.38, 5.6.0 - 5.6.40, 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
string(12) "{"foo":null}"

preferences:
213.12 ms | 404 KiB | 330 Q