Fluid UI vs Principle
| Fluid UI | Principle | |
|---|---|---|
| Free plan | Yes | No |
| Free trial | Yes | No |
| Paid from | $8.25/mo | $99/mo |
| Open source | No | No |
| Platforms | Android, iOS, Linux, macOS, Web, Windows | Web, macOS, iOS |
| Free plan | Yes | No |
| Real time collaboration | Yes | — |
| Interactive prototyping | Yes | Yes |
| Design systems | Yes | Yes |
| Desktop app | Yes | Yes |
| Prototype sharing | Yes | Yes |
Both are listed in Best UI Design Tools, Best Game UI Design Software, Best Prototyping Software. On Samsung Mobile US Press, Fluid UI scores higher on our published basis.