In this post I explain why Yoast SEO will soon warn people whose website runs on an older, unsupported, version of PHP to upgrade their PHP version. We’re doing this mainly to improve the security and speed of those websites. This post is long, but I’ll explain:
what the problem is;
why we want to fix it;
why we burden the user with it;
and how web hosts can work with us.
PHP? Versions? What are you talking about?
WordPress, (like Yoast SEO), is built in large part in a programming language called PHP. This language, as WordPress itself, has gradually improved over time. Web developers all over the world are enjoying the new features that newer versions of PHP have brought. Also, more importantly, everyone all over the world enjoys the increased security these new versions bring. Unfortunately, WordPress developers do not get to join in.
Compared to WordPress, PHP has a rather aggressive update path. PHP 5.6 will receive security patches for just under two more years, but nothing else, and no other PHP 5 version receives security updates. PHP 7 is the future (and boy is it nice and fast).
Ever since July 2011, the minimum PHP required for WordPress is PHP version 5.2. Here