Diagrams vs Mermaid
Which should you use? A side-by-side look at what each one does, who it suits, what it costs, how hard it is to set up, and where each falls short.
Open source · MIT
Python code that draws cloud architecture diagrams, rendered with Graphviz.
Open source · MIT
Generate diagrams from Markdown-like text, for docs and code.
The short answer
Choose Diagrams if you need…
- Engineers who want to sketch a cloud architecture quickly without a drawing tool
- Teams that keep architecture docs in git and want diagrams to diff and review
- People documenting an existing cloud setup from code
- Users comfortable with basic Python
Choose Mermaid if you need…
- Developers who want diagrams stored as text alongside their code and docs
- Teams whose documentation is written in Markdown and needs diagrams
- Non-programmers who want to make diagrams using the Live Editor
- Projects that generate documentation as part of a build or production script
Side-by-side
| Diagrams | Mermaid | |
|---|---|---|
| Type | Library | Dev tool |
| Price | Free and open source | Free and open source |
| Licence | MIT | MIT |
| GitHub stars | 42.8k | 91k |
| Setup difficulty | Beginner | Beginner |
| How you get it | Install with a package manager | Install with a package manager |
| Main language | Python | TypeScript |
| Last code update | 4 days ago | 4 days ago |
What each one is
Diagrams
Diagrams is a Python library where you describe a system architecture in code and it renders a diagram image. It includes icons for major cloud providers such as AWS, Azure, GCP and Kubernetes, plus on-premises, SaaS and programming nodes. Because the diagram is code, it can be tracked in version control and changed like any other source file. It does not touch real cloud resources or generate Terraform or CloudFormation.
Mermaid
Mermaid is a JavaScript tool that turns short text descriptions into diagrams such as flowcharts and sequence diagrams. You write the diagram in a Markdown-inspired syntax and the renderer draws it, so the diagram can be edited as plain text. Its stated purpose is to keep documentation up to date with development.
Best for
Diagrams
- Engineers who want to sketch a cloud architecture quickly without a drawing tool
- Teams that keep architecture docs in git and want diagrams to diff and review
- People documenting an existing cloud setup from code
- Users comfortable with basic Python
Mermaid
- Developers who want diagrams stored as text alongside their code and docs
- Teams whose documentation is written in Markdown and needs diagrams
- Non-programmers who want to make diagrams using the Live Editor
- Projects that generate documentation as part of a build or production script
Strengths
Diagrams
- Diagrams are plain Python code that can be versioned and reviewed
- Supports many providers and node types out of the box
- MIT licensed and actively maintained, with a browser playground for trying it
Mermaid
- Diagrams are plain text, so they are easy to edit, diff, and version-control
- Works inside tools such as GitHub, according to the README
- Large, active open-source project with a published documentation site
Not ideal for
Diagrams
- People who need to deploy or manage cloud resources, since it only draws diagrams and does not control infrastructure
- Anyone who wants a drag-and-drop visual editor, since diagrams are written in code
- Users who cannot install Graphviz or Python 3.9+
Mermaid
- People who need pixel-precise, freeform illustration; the README describes it as text-defined diagrams rendered by a renderer
- Users who need a visual drag-and-drop editor as their main workflow, since the README centers on text input via the Live Editor
Trade-offs
Diagrams
- Rendering depends on Graphviz being installed separately
- Layout is determined automatically, so fine positioning control is limited
- Does not read live cloud state or generate infrastructure code
Mermaid
- Layout and styling are controlled by the renderer, so fine visual control is limited by what the syntax supports
- Requires learning the Mermaid syntax for each diagram type
Getting started
Diagrams
Install with pip
pip install diagramsInstall with pipenv
pipenv install diagramsFrequently asked questions
What is the difference between Diagrams and Mermaid?
Diagrams: Python code that draws cloud architecture diagrams, rendered with Graphviz. Mermaid: Generate diagrams from Markdown-like text, for docs and code. Diagrams suits engineers who want to sketch a cloud architecture quickly without a drawing tool, while Mermaid suits developers who want diagrams stored as text alongside their code and docs.
Are Diagrams and Mermaid free?
Diagrams: Free and open source. Mermaid: Free and open source.
Is Diagrams or Mermaid more popular?
Mermaid has more GitHub stars (91k) than Diagrams (42.8k). Popularity isn't the same as fit — check which one matches your use case above.
Keep comparing
Built from our catalogue entries for both products: open-source details come from each project's README (AI-assisted, refreshed weekly) and GitHub data; AI-tool details are editorial. Spotted something wrong? Let us know from either product's page.