Free Online Diagram Tools Every Ops Engineer Should Use

1. Excalidraw

Excalidraw is an open‑source virtual whiteboard that supports flowcharts and sketches. It offers a hand‑drawn style, multi‑language UI (including Chinese), keyboard shortcuts, import of third‑party graphics, and end‑to‑end encryption so drawings never leave the browser. Users can share a web link for real‑time collaboration and paste Excel tables directly.

URL:

https://excalidraw.com/

2. Zen Flowchart

Zen Flowchart provides a simple English interface (browser translation can be used) and requires only a quick email registration. Its main features include online flowchart creation, mind‑map generation (Zen Mind Map), low‑fidelity website wireframes, a free online whiteboard for brainstorming, task management (Zen Task), and real‑time collaborative notes (Zen Notes).

URL:

https://www.zenflowchart.com/

3. Visual Paradigm Online

This service offers a large collection of ready‑made diagram templates and supports many diagram types such as UML, BPMN, ArchiMate, infographics, e‑books, and charts. It also bundles a PDF suite, design editor, resource library, online ebook reader, chart maker, photo editor, publishing tools, real‑time collaboration, form designer, and spreadsheet editor.

URL:

https://online.visual-paradigm.com/cn/

4. draw.io (diagrams.net)

draw.io is a widely‑used, “big‑player” diagramming site that works on Windows, macOS, and any browser. It supports creating flowcharts, mind maps, and network topology diagrams.

URLs: https://www.draw.io/ or

https://www.diagrams.net/

5. 迅捷画图

A domestic Chinese tool praised for its rich template library and ease of use. Drawbacks include many premium templates that require payment. Notable features are cross‑format import/export, real‑time multi‑user editing, full‑platform support, offline editing, customizable shapes and styles, automatic cloud sync every 30 seconds, one‑click sharing with password and expiration options, and version history tracking.

URL:

https://www.liuchengtu.com/

6. ProcessOn

ProcessOn is an online collaborative drawing platform that supports flowcharts, mind maps, org charts, network topologies, BPMN, UML, UI prototypes for both web and iOS, and enables real‑time sharing and collaboration over the internet.

URL: https://www.processon.com/ Which of these tools are you currently using, and do you have other recommendations?