3v4l.org

run code in 300+ PHP versions simultaneously
<?php mb_internal_encoding('UTF-8'); echo 'Subject: ', mb_encode_mimeheader('訂購網', 'UTF-8', 'B');
Output for 5.4.0 - 5.4.45, 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
Subject: =?UTF-8?B?6KiC6LO857ay?=
preferences:
273.45 ms | 404 KiB | 376 Q