Comparing OSS
UI toolkits.
Slint, Qt, Flutter, LVGL and Electron side by side
| Criterion | Slint | Qt | Flutter | Electron | LVGL |
|---|---|---|---|---|---|
| Reach, one codebase | MCU/MPU · desktop · mobile · web | MPU · desktop · mobile | Mobile · desktop | Desktop | MCU |
| Languages | Rust · C++ · JS · Python | C++ / QML | Dart | JS · HTML · CSS | C |
| Memory-safe language | ✓ Rust | ✗ C++ | ✓ via GC | ✓ via GC | ✗ C |
| Functional safety | ✓ | ✗ | ✗ | ✗ | ✗ |
| Runtime footprint | <300 KiB | Large | Large | Very large | Tiny |
Is Slint a good alternative to Qt, Flutter, LVGL, and Electron?
Yes. Slint is a declarative GUI toolkit that spans embedded, desktop, mobile, and web from a single codebase. It has a smaller footprint than Qt, Flutter, and Electron, real microcontroller support those three lack, and a declarative language with multi-language bindings that LVGL's C API doesn't offer.
How much lighter is Slint than Electron or Flutter?
Slint compiles to native machine code and does not bundle a browser engine or a large runtime. Its runtime fits in under 300 KiB of RAM, so binaries and memory use are a fraction of an equivalent Electron or Flutter app.
Which languages does Slint support compared to these toolkits?
Slint provides official APIs for Rust, C++, JavaScript/TypeScript, and Python, so you keep your existing toolchain instead of adopting Dart (Flutter), QML and C++ (Qt), or C (LVGL).
Does Slint run on microcontrollers like LVGL?
Yes. Slint runs on resource-constrained microcontrollers with a runtime under 300 KiB of RAM, and unlike LVGL it also scales up to desktop, mobile, and web from the same UI codebase.
How does Slint's licensing compare to Qt's?
Slint is available under an open-source GPLv3 license, a royalty-free license for proprietary desktop, mobile, and web apps, and a paid commercial license with support, a simpler model than Qt's.
What can Slint do that Qt, Flutter, LVGL, and Electron can't?
Slint is targetable end-to-end by an AI coding agent through its MCP server and llms.txt, so an agent can write, run, and verify a Slint UI. None of the others expose the project to AI agents that way. Slint also covers functional safety with Slint SC, in the same language and tooling, where Flutter and Electron offer nothing and Qt and LVGL rely on separate products (Qt Safe Renderer, LVGL Safe).
Deeper Dives
Memory-safe, much lighter, and a UI language that reads more easily than QML. Licensing is simpler too.
Slint vs Qt →C++, Rust, Python or JavaScript in place of Dart, a far smaller footprint, and real microcontroller support.
Slint vs Flutter →Native and small instead of a bundled browser, with the same quick edit and reload while you build.
Slint vs Electron →The same small footprint on microcontrollers, plus a UI language, live preview and a path to desktop, mobile and web.
Slint vs LVGL →A UI language designers can work in rather than Rust code, with bindings for other languages and embedded reach.
Declarative Rust GUI →