Best FLTK Alternatives & Competitors in 2025

Powerful, flexible and easy to use, Qt will help you not only meet your tight deadline, but also reduce the maintainable code by an astonishing percentage.

Key Qt features:

Cross-Platform Development Rich Documentation Mature and Stable Comprehensive UI Components

Open Source

GTK+ is a multi-platform toolkit for creating graphical user interfaces.

Key GTK features:

Cross-Platform Compatibility Rich Widget Set Open Source Language Bindings

Open Source

As the only API powered by the Prince HTML-to-PDF engine, DocRaptor provides the best support for complex PDFs with powerful support for headers, page breaks, page numbers, flexbox, watermarks, accessible PDFs, and much more.

Key DocRaptor features:

Ease of Use Customizable High-Quality Rendering Compliance

Try for free paid Free Trial $15.0 / Monthly (125+ Documents)

wxWidgets: Cross-Platform GUI Library.

Key wxWidgets features:

Cross-Platform Native Look and Feel Wide Range of Widgets Extensive Documentation

Open Source

A multi-platform .NET UI framework.

Key Avalonia features:

Cross-Platform MVVM Support Rich Styling System Open Source

Open Source

Build beautiful native apps in record time 🚀.

Key Flutter features:

Cross-Platform Development Hot Reload Rich Set of Pre-Built Widgets Performance

Open Source

Build Mobile, Desktop and WebAssembly apps with C# and XAML.

Key Uno Platform features:

.NET IDEs Cross-Platform Development Hot Reload Native Performance

Open Source free

Dear ImGui: Bloat-free Graphical User interface for C++ with minimal dependencies.

Key Dear ImGui features:

Immediate Mode GUI Lightweight Cross-Platform Customizable and Extendable

gtkmm is the official C++ interface for the popular GUI library GTK+.

Lara Web Engine is a C# Web UI framework supporting web component development and reactive programming. - integrativesoft/lara.

Key Lara features:

Open Source Community Support Customization Transparency

Open Source

SPA front-end on steroids.

Key Quasar Framework features:

Versatile UI Components Cross-Platform Development Performance Optimization Developer-Friendly

Build cross platform desktop apps with web technologies.

Key Electron features:

Cross-Platform Compatibility Web Technologies Rich Ecosystem Auto-Update Mechanism

Open Source

IUP is a multi-platform toolkit for building graphical user interfaces.

A free and modular front-end framework for developing fast and powerful user experiences.

Key Maui Project (MauiKit) features:

Cross-Platform Compatibility Consistent UI/UX Open Source Ease of Use