Gaphor

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Score7.0

Rank#6 of 24

PriceFree

Free planYes

Runs onLinux, macOS, Windows

Summary

Gaphor is a free desktop modeling application for UML, SysML, RAAML, and C4, used to visualize and document applications and systems. It implements a UML 2 data model and the UML, SysML, and RAAML OMG standards, and supports C4. Users can create diagrams such as Class, Interaction, State Machine, Block Definition, and Requirements diagrams, mix diagram items, and customize styling with its built-in engine. Diagrams export to SVG, PNG, PDF, or EPS, and models can be batch-exported. Gaphor can also produce a self-contained, static, interactive, read-only HTML model report that needs no server or backend to view. As a Python library, it can inspect, generate, or update models through scripts or Jupyter notebooks. A Sphinx extension embeds diagrams in reStructuredText or Markdown documentation. Gaphor is open source under the Apache 2 license and runs on Windows, macOS, and Linux. Windows installation options include an installer, portable version, or Winget; macOS 10.15 or newer is required. Linux options include Flatpak, Arch, and Debian/Ubuntu packages.

Who it is for

Gaphor suits people documenting or visualizing software and systems with UML, SysML, RAAML, or C4. It also fits users who want to script model changes or include diagrams in documentation.

What is good

Supports UML, SysML, RAAML, and C4.
Exports diagrams as SVG, PNG, PDF, or EPS.
Batch-exports all diagrams in a model.
Generates a self-contained HTML model report.
Available on Windows, macOS, and Linux.

What to know first

macOS requires version 10.15 or newer.
It is a desktop application, not a web service.

Verdict

Gaphor brings standards-based modeling, multiple export formats, and Python scripting into a free desktop application. Its report generation and documentation integration may suit users who need model diagrams beyond the application itself.

Gaphor plans and pricing

All plans

Gaphor Free 100% open source · Apache 2 license gaphor.org · 29 Sept 2026

Compared on UML modeling software

Free plan: Yesgaphor.org
UML diagram types: Class, Component, Action, Sequence, Interaction, State Machine, Use Case, Deployment, Information Flowgaphor.org
Code generation: Yesgaphor.org
Team collaboration: Yesgaphor.org
Deployment: desktopgaphor.org
Supported platforms: Windows, macOS, Linuxgaphor.org
Model repository: Yesgaphor.org

Facts

Purpose: Gaphor is a modeling application for UML, SysML, RAAML, and C4 used to visualize and document applications and systems.gaphor.org · 29 Sept 2026
Modeling standards: Gaphor implements a fully compliant UML 2 data model and the UML, SysML, and RAAML OMG standards, and supports the C4 model.gaphor.org · 29 Sept 2026
Diagram types: It supports diagrams including Class, Interaction, State Machine, Block Definition, and Requirements diagrams, and lets users mix diagram items.gaphor.org · 29 Sept 2026
Model styling: Users can customize diagrams with a built-in styling engine.gaphor.org · 29 Sept 2026
Extensibility: Gaphor can be extended with plugins and users can access their own extensions through the GUI or CLI.gaphor.org · 29 Sept 2026
Export: Gaphor exports diagrams as SVG, PNG, PDF, or EPS and can batch-export every diagram in a model.docs.gaphor.org · 29 Sept 2026
HTML reports: It can generate a self-contained, static, interactive, read-only HTML report of a model that requires no server or backend to view.docs.gaphor.org · 29 Sept 2026
Scripting: Gaphor can be used as a Python library with scripts or Jupyter notebooks to inspect, generate, or update models.docs.gaphor.org · 29 Sept 2026
Documentation integration: Gaphor provides a Sphinx extension for embedding its diagrams in reStructuredText or Markdown documentation.docs.gaphor.org · 29 Sept 2026
Support: The project provides community contact through Matrix chat and accepts issue reports through GitHub.gaphor.org · 29 Sept 2026
Windows distribution: Windows users can download an installer or portable version, or install Gaphor with Winget.gaphor.org · 29 Sept 2026
macOS requirement: The download page says Gaphor requires macOS 10.15 or newer and provides ARM and Intel installers.gaphor.org · 29 Sept 2026
Linux distribution: The download page recommends Flatpak for Linux and also lists Arch and Debian/Ubuntu packages.gaphor.org · 29 Sept 2026