When comparing Discourse vs Flarum, the Slant community recommends Flarum for most people. In the question“What are the best web forum software packages?” Flarum is ranked 1st while Discourse is ranked 2nd.
Ranked in these QuestionsQuestion Ranking
Pro Has a built-in immune system from trolls, spammers and bad actors
Discourse has a simple user trust system that makes moderating the forum a lot easier. Users gain more permissions as they gain more trust, which limits the amount of damage spammers and trolls can do. Discourse co-founder Jeff Atwood also founded StackExchange, which is the gold standard for gamification/moderation systems so you can also expect Discourse to get better and better at moderation.
Pro Modern & polished UI/UX with lots of great smaller features
The best feature is its design: discourse is designed to aid in the creation of high quality online conversations. Flat discussions with well implemented quoting systems, expandable/collapsible replies, infinite scroll, clean UI and many more features come together to form a highly polished forum experience that makes legacy forums show their age.
Pro Effective search
Pro 100% free and fully open source
Discourse is powered by Ruby on Rails, Ember.js, PostgreSQL and Redis. The code is licensed under GPL and available on GitHub.
Pro Good to go out of the box yet infinitely tweakable
Discourse has sane, safe out of the box defaults, but a million dials and knobs to tweak.
Pro Helpful community
Discourse has a comprehensive forum culture support hub at meta.discourse.org.
Pro Official Akismet Anti-Spam Plugin
Official Akismet plugin vets posts by new users to make sure they don’t look spammy before they hit your site. Akismet key purchase required.
Pro Live preview while editing the post
The post editor has a synchronized side-by-side preview of the Markdown rendering of the post.
Pro Hosted and self-hosted solutions
You can host it yourself in a $5 cloud server or on any Linux server you already have. And if you don't want to deal with this, you can use the hosting platform from the development team.
Pro User selectable themes
Users can choose between the themes made avaliable on their instances, and even use different themes on different devices (mobile vs desktop, for example).
Pro Easy one-click upgrade
Discourse can upgrade itself with one click in the admin panel. Not the same can be said about MyBB, or most other forums.
Pro Discussions can be organized in categories and tagged
Discussions can be tagged with an arbitrary number of tags, separately from categories. Categories are hierarchical and don't scale; tags do.
Runs in modern browsers and works identically on desktop and tablet and smartphone without the need for a native app.
Pro Extensible via plugins
Pro Export your posts
Pro Good on-boarding experience for new users
New users are greeted withe the disco bot which has an interactive experience to teach the basics of using Discourse.
Pro Very fast loading time
Pro Based on (but not built with) Laravel
Flarum was originally based on Laravel and uses the Eloquent ORM. But it is not a traditional Laravel software.
Pro Easily expandable
Pro Open Source
Pro Great community
The community building flarum is fantastic and very helpful!
Pro Lots of features
The developers do a great job adding new bells and whistles.
Pro Modern UI
Pro Mobile Friendly UI
Con Complicated setup
Compared to standard PHP+MySQL apps, Discourse is more complicated - the app lives in a Docker container. However, a Docker image is available, which reduces the setup time to about 30 minutes.
Con Leaves out users with shared hosting
Discourse requires sudo, which is only available on a VPS.
Con Bad noscript support
When using a Discourse forum without scripts the experience is greatly reduced. It's really hard to use and is read-only, meaning that one can't comment or create threads without scripts.
Con It is more "Free to Try" than really free
Con Extremely expensive hosting
Discourse hosting is very expensive. Almost nobody would pay for it.
Con Slow development
Development moves at a glacial pace.
Con Complicated installation process on shared hosts
PHP Composer is used as a dependency manager. Because of that SSH access is needed which makes Flarum harder to install than, for instance, Vanilla or phpBB. Especially on shared hosts where no SSH access is available or where shell access is severely limited.