In simple English
Pencil is a free program for drawing user interfaces and diagrams. You can sketch how a website or phone app will look before you write any code. It runs on your computer and helps you drag and drop shapes to build visual mockups. The project is open source and costs nothing to use. It has been around for years, so some parts of the code are older.
What it is
Pencil is a desktop application built on Electron (a way to run a program inside its own sealed box, so it cannot break anything else on your server) for creating mockups and wireframes. It provides built-in shape collections for drawing app layouts, diagrams, and user interfaces.
What it is good for
Solo builders who need to sketch out an app screen or layout quickly before starting to code will find this helpful. It keeps your design drafts organised in one place without requiring an ongoing monthly subscription.
- Completely free and open source to download and use.
- Runs locally on your computer without needing an internet connection.
- Includes built-in shapes for sketching websites and mobile apps.
- The latest release is older, so some dependencies may require attention.
- Export options and printing can occasionally behave inconsistently on modern operating systems.
- The user interface feels dated compared to newer web-based design tools.
Figma or paid mockup software for basic wireframing
Inkscape for vector graphics and detailed logo work
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git clone https://github.com/evolus/pencil.git cd pencil npm install npm start