Lucidchart
lucidchart.com
Polished diagramming with real-time collaboration and smart layout
Free tier
Loading page
diagrams.net
Full diagram editor that works without an account or a saved file.
The tool people still call draw.io: flowcharts, network diagrams, ERDs, UML, org charts, floor plans, with shape libraries for AWS, Azure, GCP and Kubernetes included. It asks where to store the file first — device, Google Drive, OneDrive, GitHub — and if you pick device, nothing touches their servers. Exports to PNG, SVG, PDF and a `.drawio` XML file you own. The interface is dense and dated, and it does no layout for you.
AltFTool does this too
If you would rather not leave the site, Flow Chart Maker covers the same job here — free, no account, and it runs in your browser.
Open Flow Chart MakerQuestions
Works the moment the page loads. No account, no email, no trial. No automatic layout — a fifty-box diagram is fifty boxes you positioned yourself.
No. diagrams.net does the work inside your browser, so the file never leaves your device — you can load the page, disconnect from the network, and it still works. That makes it a reasonable choice for material containing personal data.
No automatic layout — a fifty-box diagram is fifty boxes you positioned yourself.
Alternatives
Same category or same task, ordered by how closely they overlap.
lucidchart.com
Polished diagramming with real-time collaboration and smart layout
plantuml.com
Renders UML from a text description, with the source encoded in the URL
mermaid.live
Write a diagram as text and watch it render beside you
sequencediagram.org
Purpose-built editor for sequence diagrams, typed rather than dragged
asciiflow.com
Draws boxes and arrows as plain ASCII you can paste into a comment
excalidraw.com
Hand-drawn-looking whiteboard that opens instantly with no sign-up