🎨 The open-source Claude Design alternative. 🖥️ Local-first desktop app. 🖼️ Your coding agent becomes the design engine: prototypes, landing pages, dashboards, slides, images & video — real files, HTML/PDF/PPTX/MP4 export. 🤖 Claude Code / Codex / Cursor / Gemini / OpenCode / Qwen & 20+ CLIs via BYOK.

Penpot: The open-source design platform for Product teams that need scalable collaboration.

Collection of custom elements that appear hand drawn. Great for wireframes or a fun look.

The Pencil Project's unique mission is to build a free and opensource tool for making diagrams and GUI prototyping that everyone can use.

Design and prototype customized UI, interaction, navigation, transition and animation for App Store ready Apps in Interface Builder with IBAnimatable.

Mockoon is the easiest and quickest way to run mock APIs locally. No remote deployment, no account required, open source.

🎨 React application prototyping tool for developers and designers 🏗️

Run Claude Design locally as an Agent Skill — Cursor, Claude Code & more. Produce polished UI mockups, prototypes, decks & wireframes as self-contained HTML, without claude.ai/design. Best with Opus 4.8.

dnd visual editor - mockups and code in one go!

Turn Python scripts into handouts with Markdown and figures

DEPRECATED: Multiplatform GUI Prototyping/Wireframing

Quickly try out any Swift pod or framework in a playground

A Ruby DSL for prototyping card games.

✔️ Mock data for your prototypes and demos. Remote deployments to Zeit now.

Browser-based MDX editor

Mmock is an HTTP mocking application for testing and fast prototyping

Charm: A Framework for Rapidly Prototyping Cryptosystems

🚧 Build web pages with Vuse, the next-gen interactive page builder powered with Vue.js.

Flexible layout tool for creating UI on any platform

Web based diagramming app that lets you build interactive diagrams and prototypes