Shifter is a static site generator SaaS. So some plugins for WordPress (e.g. contact forms, e-commerce, site searches) won't work. When generating the static files, Shifter will automatically disable unsupported plugins. Here's a list of what's unsupported along with some alternatives.
For more information, read our blog post about this topic.
List of unsupported plugins and default features
Comments in WordPress need to be switched to the following external services:
Here's documentation that can help you integrate your site with Disqus.
BBS and messageboards
BBpress needs to be replaced with something like Zendesk and the documentation (with images) to do this is here.
BuddyPress or other membership plugins which work dynamically with PHP won't work on Shifter.
Our WP Serverless Forms plugin to work with ContactForm7! Please check below document for setting up with Basin!
Using WP Serverless Forms WordPress Plugin with Basin
You (and we!) love the Rest API, but it is not for Shifter. REST API will work when you are logged in to your admin dashboard, but not when end-users are on the static site. There's no alternative for this, unfortunately.
Maintenance mode, Under construction mode or Coming soon
Shifter will not cover these kind of plugins, and no alternatives.