Five diagram modes that know their own rules - so the diagram argues back when the thinking is wrong. Files live on your machine as plain text. No account, no cloud, no subscription.
Lifetime licence · Free updates · Windows and Linux coming soon
diagram modes, each with its own rules
once - no subscription, no seats
accounts, servers or cloud sync
A generic canvas lets you draw a flow chart that could never run. Arity's modes carry the rules of the notation, and tell you the moment a diagram stops making sense.
A decision has exactly two ways out. A process has one. Arity enforces it while you draw, and marks the node that breaks the rule.
Classes, interfaces, abstract methods. Inheritance is checked as you connect: unimplemented methods and cycles surface immediately.
Crow's foot or Chen, switched per file. Entities auto-size to their attributes; keys are marked, not typed by hand.
Buzan's rules, built in. One keyword per branch, colour inherited down the tree, curves that taper as they travel outward.
No rules at all. The hand-drawn canvas for when the thinking has not settled into a shape yet.
Each diagram is a readable .arity file in a folder you chose. Put it in git, on a USB stick, anywhere. Nothing is uploaded.
Open a presentation window and drag it to the projector. The room sees the diagram, its name, and your pointer - never your toolbars, your file tree, or your notes. Everything you draw appears there as you draw it.
Buy Arity - $19.99Buy it once and it stays working - including every update. If you ever stop paying attention to us, nothing stops working, because your diagrams are files you already have.
Your licence key arrives by email. Activate it in Settings → License.
The download is the full app. Unactivated, it keeps three diagrams per folder and marks the presentation window - enough to decide whether it earns its place.