Top 7 Free Online Diagramming Tools for Network Engineers

Zen Flowchart

Zen Flowchart is a simple, English‑language online tool that requires only a quick email registration. It offers flowchart creation, writing, note‑taking, mind‑mapping, and real‑time collaboration, making it ideal for rapid diagramming.

Online address: https://www.zenflowchart.com/

Excalidraw

Excalidraw is an open‑source virtual whiteboard that lets you draw flowcharts and diagrams in a hand‑drawn style. It supports multiple languages (including Chinese), imports third‑party assets, offers keyboard shortcuts, and allows Excel table pasting. No registration is needed, and it provides end‑to‑end encryption with shareable web links.

Online address: https://excalidraw.com/

draw.io

draw.io (also available at https://www.diagrams.net/) is a widely used, cross‑platform diagramming site that works on Windows, macOS, and browsers. It excels at creating network topology diagrams and integrates with VS Code for extended functionality.

Online address: https://www.draw.io/

xGraph

xGraph is similar to draw.io but adds component and node search, private sharing, and encrypted links with access keys for secure diagram distribution.

ProcessOn

ProcessOn is an online collaborative drawing platform supporting flowcharts, mind maps, org charts, network topologies, BPMN, UML, UI prototypes, and iOS prototypes. It enables real‑time teamwork and sharing via the internet.

Online address: https://www.processon.com/

Liuchengtu (迅捷画图)

Liuchengtu offers a large template library and both online and desktop versions. While many templates require payment, it provides free users with limited files and templates, making it less advantageous compared to fully free alternatives.

Online address: https://www.liuchengtu.com/

Nutstore Drawing (坚果云绘图)

Nutstore Drawing, part of the Nutstore cloud storage service, is a completely free diagramming tool that can be accessed via New → Drawing File → Edit within a Nutstore folder. It supports unlimited diagram storage and real‑time sync for team collaboration.

Online address: (access through Nutstore interface)