run code in 200+ php & hhvm versions
Bugs & Features
<?php mb_internal_encoding('UTF-8'); echo 'Subject: ', mb_encode_mimeheader('→', 'UTF-8', 'B');

Shows result from various feature-branches currently under review from the php developers. Contact me to have additional branches featured.

Output for Typed properties v2
Subject: =?UTF-8?B?4oaS?=
Output for Array change keys
Subject: =?UTF-8?B?4oaS?=
Output for Lexical anon
Subject: =?UTF-8?B?4oaS?=

Archived branches

Once feature-branches are merged or declined, they are no longer available. Their functionality (when merged) can be viewed from the main output page