draw.io Alternatives

LucidChart is the missing link in online productivity suites. LucidChart allows users to create, collaborate on, and publish attractive flowcharts and other diagrams from a web browser.

yEd is a free desktop application to quickly create, import, edit, and automatically arrange diagrams. It runs on Windows, Mac OS X, and Unix/Linux.

PlantUML is an open-source tool that uses simple textual descriptions to draw UML diagrams.

Open Source

Simplify and communicate complex information using data-linked diagrams.

OmniGraffle is for creating precise graphics like website wireframes, an electrical system designs, or mapping out software class.

Dia is a GTK+ based diagram creation program for GNU/Linux, MacOS X, Unix, and Windows, and is released under the GPL license.

StarUML

UMLGraph is a professional automated drawing tool that allows the designers the declarative specification and drawing of UML class and sequence diagram.

Gliffy is a powerful HTML5 online diagram maker. Create a flow chart, network diagram, UML diagram, organizational chart or wireframe with ease.

An all-in-one diagram software for flowchart, org chart and more.

UMLet - Free UML Tool for Fast UML Diagrams

Umbrello UML Modeller is a Unified Modelling Language diagram programme for KDE.

Graphviz is open source graph visualization software. It has several main graph layout programs.