Free & Open Source Best for: Quick, free, and open-source GUI prototyping and diagramming for desktop users.
Always free, open-source with GNU General Public License v3.0.
✓ Pros
- Free and open-source
- Easy to use for quick mockups and wireframing
- Available on multiple desktop platforms (Windows, macOS, Linux)
- Includes a wide range of built-in shape collections for desktop and mobile UI (Android, iOS)
- Supports diagram drawing and flowcharts
- Exports designs to various formats (PNG, SVG, HTML, PDF, ODT)
- Ability to find and import cliparts from the internet
- Supports inter-page linking to define UI flow
✕ Cons
- Limited tools for creating custom shapes easily
- User experience can sometimes feel underwhelming
- Not as feature-rich as some commercial mockup tools
- Difficulty in switching pages between different projects without manual file editing
- Potentially limited community support compared to commercial alternatives
- No browser-based version, only a desktop application