Free editor / free UML editor
free UML editor

Free UML editor for software diagrams online

Use diagram.now when a software design needs a diagram before it needs a formal tooling decision. Draft UML class diagrams, sequence diagrams, component diagrams, deployment diagrams, and architecture sketches in the browser.

Start a free UML diagram Use in Confluence

Best first template

UML sequence diagram for login, token refresh, and service authorization.

Free-first funnel

Send search visitors to the browser editor first. Ask for Marketplace install only after they know the diagram is useful.

Confluence upgrade

When the diagram belongs in a spec, runbook, ADR, or process page, install diagram.now so it stays editable beside the docs.

Make design reviews easier to scan

A UML diagram helps reviewers understand structure and flow before they debate implementation details. Keep the first version simple: the classes, services, dependencies, or sequence that matter for the decision.

UML diagrams that belong in docs

Use UML for API auth flows, service boundaries, deployment topology, domain models, major classes, state transitions, and integration contracts.

Move long-lived UML into Confluence

If the diagram becomes part of an ADR, RFC, implementation plan, or onboarding page, use the Confluence app so teammates can update the visual where the discussion already happens.

Start free, then bring it into Confluence

Use the browser editor for the first draft. If the diagram becomes team documentation, install diagram.now from Atlassian Marketplace and keep it editable inside Confluence.

Start drawing free Install from Atlassian Marketplace

FAQ

What UML diagrams can I create?

Use diagram.now for common UML-style diagrams including class, sequence, component, deployment, package, activity, and state-oriented visuals.

Is the UML editor free?

The web editor should be positioned as the free entry point. If a team wants Confluence-native editing, point them to the Atlassian Marketplace app.

What is the fastest UML diagram to start with?

Start with a sequence diagram for one user action or a class/domain model for one bounded part of the system.

Related free diagram pages