AI tools by job · DiagramForge Studio

UML diagram maker

Type what the system does, like "a library where members borrow books and librarians manage stock", and DiagramForge draws the UML for it. Ask for a class diagram and you get classes with their fields and methods, joined by proper inheritance and composition arrows. Ask for a sequence diagram and you get the people and services across the top, with every message in order. State and use case diagrams work the same way. If you just say "UML diagram", it makes a class diagram.

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1 credit · guests get 2 free credits a day, free accounts get 5

Who it's for

Computer science students with UML assignments
Developers planning a feature before writing code
Teams explaining a system in a design doc
Teachers making examples for a class

What you get

Class diagrams with fields, methods, interfaces and the right arrow ends
Sequence diagrams with lifelines and every call in order, replies dashed
State diagrams with start and end dots and labelled events
Use case diagrams with actors inside a system boundary
SVG, PNG and Mermaid code for GitHub, Notion or a report

How it works

Describe the system and say which diagram you want, or leave it and it picks one.
In Adjust you can choose the type (UML class, UML sequence, state or use case) and the look.
Press Draw diagram (1 credit). Drag boxes, edit any class or message for free, and use Walk to go through it step by step.
Download SVG or PNG for your report, or copy the Mermaid code.

Example request

“Sequence diagram of a user logging in with a one-time code sent by SMS”

What comes back

The user, web app, login service, code store and SMS gateway across the top
Every message in order, from typing the phone number to opening the dashboard
Replies drawn as dashed arrows
A message for when the code is wrong or has expired

Tips for a better result

Name the main parts of your system so they become the classes or participants.
For a sequence diagram, describe one action from start to finish, like logging in or placing an order.
Use Walk to check each class or message before you hand it in.
Copy the Mermaid code if your course or team writes in Markdown.

Questions

Is it free?

Drawing a diagram costs 1 credit, and guests get 2 free credits every day (5 with a free account). Moving boxes, editing text, fields and methods, and every download are free. Asking the AI for a change costs 1 credit.

Which UML diagrams can it make?

Class, sequence, state and use case diagrams. It also makes activity diagrams, which are flowcharts with a start dot and end dots.

Can I change the diagram?

Yes. Drag any box, rename it, edit a class's fields and methods, add or remove arrows, or type a change in the box below the board.

Does it export Mermaid or PlantUML?

Mermaid, for class, sequence and state diagrams. There is no PlantUML export yet. SVG and PNG work for every diagram.

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