Architecture Diagram Generator — Free Online Tool

Create Mermaid architecture diagrams offline from services and dependency lists for system design, cloud architecture, DevOps handoffs, and runbooks.

Use this free online Architecture Diagram Generator directly in your browser. No signup required, no data leaves your device. Part of Utilier — a collection of 133+ developer utilities.

What is Architecture Diagram Generator?

Architecture Diagram Generator turns simple service and dependency lists into Mermaid flowcharts. It helps developers, system architects, DevOps engineers, and cloud operations teams document system shape without leaving the browser.

  • Service mapping: Describe services as id, label, and group to build grouped architecture diagrams.
  • Dependency flow: Describe edges as source -> target with optional labels such as protocol or data flow.
  • Mermaid output: Copy or download Mermaid text for README files, design docs, ADRs, and runbooks.

Why use architecture diagram generator?

Architecture diagrams become stale when they require heavy tooling. This generator makes lightweight diagrams fast enough to keep close to code.

  • Offline: Runs entirely in the browser and does not send system details anywhere.
  • Portable: Mermaid works in many documentation systems including GitHub, GitLab, and internal wikis.
  • Operational: Useful for incident runbooks, onboarding, and cloud handoff documents.

When to use architecture diagram generator

Use when you need a quick, maintainable system diagram.

  • Documenting services before a design review.
  • Creating diagrams for architecture sections in README or docs.
  • Capturing dependencies during incident analysis or migration planning.

How to use architecture diagram generator

Enter services and dependencies, then generate Mermaid.

  1. List services: Use one service per line in the format id | label | group.
  2. List dependencies: Use one edge per line in the format source -> target : label.
  3. Generate: Copy or download the Mermaid diagram for documentation.

Key features

  • Grouped diagrams: Service groups become Mermaid subgraphs.
  • Direction control: Choose LR, TD, TB, or RL layout direction.
  • Documentation-ready: Generated output can be pasted into markdown Mermaid blocks.

Privacy and availability

  • Runs entirely in your browser — zero server processing
  • No signup or account required
  • Works offline once loaded
  • Fast, lightweight, no external dependencies
  • Available as a browser extension for Chrome and Firefox