In previous article, I have mentioned Free Adobe Photoshop Alternative but now in this article, I have mentioned best free and open-source UI mockup tool, which a UI or Graphic designer, can use to create mock-ups or wireframe for free.

1. Pencil Project

Pencil project is an open-source GUI prototyping tool that's available for ALL platforms (Windows, Mac or Linux).

Pencil is built for the purpose of providing a free and open-source GUI prototyping tool that people can easily install and use to create mockups in popular desktop platforms.


  • Easy GUI Prototyping
  • Provides built-in shapes, Pencil provides various built-in shapes collection for drawing different types of user interface ranging from desktop to mobile platforms.
  • Diagram Drawing Support
  • You can have your drawing exported as a set of rasterized PNG files or as a web page that can be delivered to the viewers
  • Pencil has a clipart browser tool that integrates with to let users easily find cliparts by keywords and added them into the drawing by a simple drag-and-drop operation
  • Elements in a drawing can be linked to a specific page in the same document. This helps user define the UI flow when creating application or website mockups


open-source-ui-tools-graphic-designer-min.png is a completely free and open-source wireframing software that feels similar in UI to Google Docs.


  • Users can export designs to their Google Drive, Microsoft OneDrive, their desktop.
  • Integrations with Gliffy, Lucidchart and more.
  • Free and Browser based.

3. is one of the most popular wireframe open source tools out there that can be accessed by visiting its web source.


  • You can draw a new element by clicking and dragging your mouse cursor across the canvas and selecting a stencil from a pop-up menu.
  • Enabling the smart guides allows you to draw with greater precision and speed.
  • You can export wireframes to a PDF file or a series of PNG files.
  • Create master pages, so you don't need to create same elements in multiples pages
  • Pages can be linked

4. Framebox


Framebox is also another completely free wireframing tool on this list.


  • It is a drag-and-drop tool that allows designers to sketch wireframes using UI elements.
  • Save progress and History
  • Free and Browser based.
  • Allows you to create custom link and share it with team.

5. Mydraft.CC is a completely open source and free wireframing tool that is accessible anywhere you can use a browser.


  • Free and browser based, so this is also cross-platform
  • Drag and Drop functionality to add button, checkbox etc
  • You can also add icons
  • Can add multiple pages and link them

That's it, these were some of the top free and open-source UI tools or you can say free and open-source wireframe tools for Graphic designers.

You may also like to read:

Best Notion alternatives (open source and free)

Best Free Alternatives for Obs Studio

Best AnyDesk Alternatives (Open-Source and Free)

Best Free Datagrip alternatives (Open Source)