Class / UML
Class diagram generator — UML classes from text
Describe your types and how they relate, and ChartCraft draws the UML class diagram — attributes, methods, inheritance, and associations — no XML and no manual layout.
Prose in. Diagram out.
You type
An Animal has a name and can makeSound(). Dog and Cat both inherit from Animal. A Shelter holds many Animals and has an address.
ChartCraft draws
How it works
Describe it
Write what you want in plain English — no syntax to learn.
ChartCraft compiles
It parses your description, builds the structure, and runs an automatic layout.
Refine & export
Tweak with follow-up messages, then export clean SVG or PNG.
Why ChartCraft
Attributes & methods
Each class shows its fields and operations with visibility, laid out in standard UML compartments.
Inheritance & relations
Generalisation, association, and composition rendered with the right UML connectors.
No XML headache
Skip PlantUML syntax and hand-editing — describe the model and get the diagram.
The notation, in 30 seconds
The UML class box and the five arrows that matter. Arrowheads carry the meaning — hollow triangle for “is-a”, diamonds for “owns”.
| Element | What it means |
|---|---|
| Class box | Three stacked compartments: name, attributes (name: type), methods (call()). |
| Inheritance (hollow triangle) | “Is-a”. Dog ▷ Animal. The triangle touches the parent. |
| Realization (dashed + triangle) | “Implements”. A class fulfilling an interface's contract. |
| Association (plain line) | “Knows about”. Add multiplicities at the ends: 1, 0..1, *. |
| Aggregation (hollow diamond) | “Has, but doesn't own” — parts survive the whole. Team ◇ Player. |
| Composition (filled diamond) | “Owns” — parts die with the whole. Order ◆ OrderLine. |
Real examples, generated the same way
From the public examples gallery — every one produced from a plain-English description. Open one to see its prompt.
Questions
How do I generate a UML class diagram?
Describe your classes, their attributes and methods, and how they relate. ChartCraft renders a UML class diagram, automatically laid out.
Does it show inheritance?
Yes — inheritance, associations, and composition are drawn with standard UML notation.
Is it free to use?
Yes — 3 diagrams free with no account, then 5 a month on a free account.
What's the difference between aggregation and composition?
Both are “has-a” diamonds. Composition (filled) means exclusive ownership — delete the Order and its OrderLines go with it. Aggregation (hollow) means the parts live independently — disband a Team and the Players remain.
Should every class in my codebase appear in the diagram?
No. A useful class diagram tells one story about the domain — 5 to 12 classes. Generate separate diagrams for separate subsystems rather than one wall-sized chart.