The best Flat UI alternatives
3 tools that do a similar job to Flat UI, 3 of them open source. Each entry says what it does and who it suits, so you can pick the one that fits instead of the most famous.
You're replacing
Flat UIA flat-style visual theme and component set built on Bootstrap, for ready-made web pages.
- 1

Bootstrap
Open source · MIT · ★ 175k
A free front-end toolkit of ready-made CSS and JavaScript for building responsive websites.
Best for: Developers building responsive websites or web app interfaces quickly; Teams that want a common design system with ready-made components
- 2

Tabler
Open source · MIT · ★ 42k
Free, open source Bootstrap 5 admin dashboard UI kit with dark mode and RTL support.
Best for: Developers building internal admin panels or dashboards quickly; Teams already comfortable with Bootstrap who want ready-made components
- 3

AdminLTE
Open source · MIT · ★ 45.7k
Free Bootstrap 5 admin dashboard template with responsive layouts and dark mode.
Best for: Developers building an internal admin panel or back-office tool quickly; Teams that already use Bootstrap and want a consistent dashboard look
How we pick: tools in the same category that solve the same problem, projects that name each other as alternatives, and open-source projects that describe themselves as an alternative to Flat UI. We don't take payment for placement.