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UMLet vs nomnoml: catalog facts
UMLet	nomnoml
Free Free and open source; donations are accepted through GitHub Sponsors, Patreon and PayPal.	Free Free and open source under the MIT licence.
Windows, macOS, Linux, Web	Web, Command line
Sequence and activity diagrams can be created from plain text Exports to EPS, PDF, JPG, SVG and the clipboard	Readable syntax that resembles the drawn diagram Instant live preview in the browser
Focused on drawing diagrams rather than full model-driven design Plain interface may feel basic next to commercial modelling tools	Web editor stores diagrams only in browser local storage Smaller range of diagram types than PlantUML
Downloadable app, Web application	Downloadable app, Web application
Open source	Open source
License: GPL-3.0-or-later	License: MIT
No account needed	No account needed
Works offline	Not stated if it works offline
Official website Full listing and sources Checked October 2, 2026	Official website Full listing and sources Checked October 2, 2026

Catalog facts only. Anything “not stated” is unconfirmed. Check full listings for details.