Pencil is a free and open-source tool for making diagrams and GUI prototyping.

Is Pencil open source?

Yes. Pencil is open source under the GPL-2.0 licence. Its source code is on GitHub at evolus/pencil and is written mainly in JavaScript.

Yes. Pencil is open source, so the software itself is free to use.

Can I self-host Pencil?

Yes. Pencil can be self-hosted on your own server or infrastructure.

What is Pencil an alternative to?

Pencil is an open-source alternative to Uizard, Visily, Lucidchart and Balsamiq. Other open-source alternatives to Uizard include Penpot and OpenPencil.

Is Pencil actively maintained?

Yes. The most recent commit to Pencil was on 13 October 2026, and the latest release is v3.1.1, published on 1 January 2023. The project has 9.9k stars on GitHub.

Pencil: open-source alternative to Uizard, Visily

About Pencil

Pencil is an open-source GUI prototyping tool available for all platforms. It is designed for creating mockups and diagrams. The tool is intended for anyone who needs to build user interface prototypes.

Key features

Free and open-source
Available for all platforms
Used for making diagrams and GUI prototyping
Stability fixes and new features in version 3.1.1

Built with: JavaScript tools; Node.js tools; Electron tools
Tags: gui prototyping; mockups; diagrams; open-source; cross-platform

Pencil: questions and answers

What is Pencil?: Pencil is a free and open-source tool for making diagrams and GUI prototyping.
Is Pencil open source?: Yes. Pencil is open source under the GPL-2.0 licence. Its source code is on GitHub at evolus/pencil and is written mainly in JavaScript.
Is Pencil free?: Yes. Pencil is open source, so the software itself is free to use.
Can I self-host Pencil?: Yes. Pencil can be self-hosted on your own server or infrastructure.
What is Pencil an alternative to?: Pencil is an open-source alternative to Uizard, Visily, Lucidchart and Balsamiq. Other open-source alternatives to Uizard include Penpot and OpenPencil.
Is Pencil actively maintained?: Yes. The most recent commit to Pencil was on 13 October 2026, and the latest release is v3.1.1, published on 1 January 2023. The project has 9.9k stars on GitHub.