How to draw a network diagram
- 1
Add devices
Click a device in the palette to drop it in the middle of the canvas, or drag it to the exact spot. There are ten kinds: router, switch, firewall, PC, server, access point, printer, NAS, hub and a WAN cloud.
- 2
Connect them
Drag from a device's edge dot to another device, or choose Connect and tap both. The ports are picked the way an engineer would pick them — access ports for hosts, uplinks for switches and routers — and any port can be changed in the properties panel.
- 3
Name and address them
Select a device to set its hostname, IP addresses and default gateway. Each setting is typed into the device's console for you, and the panel shows the exact commands. A cable to a router port enables that port.
- 4
Mark it up
Add labels, shaded zones such as Building A or DMZ, and arrows. Tidy lays the network out with upstream devices on top, each one above what it feeds.
- 5
Add shapes, flowcharts and UML
Open a shape library — General, Misc, Advanced, Basic, Arrows, Flowchart, Entity Relation or UML — and click a shape to add it, or drag it into place; double-click a shape to type in it. Pick a connector style, such as an arrow, a UML composition or a crow's-foot one-to-many, then drag from one shape's edge dot to another to join them.
- 6
Export
Download a PNG or SVG image, a PDF with the addressing table, cable schedule and device configs, a draw.io file to keep editing elsewhere, spreadsheet CSVs, every device's configuration as one text file, or a NetForge JSON file.
- 7
Simulate
Press Simulate and the same network opens in the NetForge-AI lab, where you can ping across it and configure it further. The lab runs up to 5 devices without a paid plan; select part of a bigger diagram to simulate just that part.
Export formats
| Format | Best for | What is in it |
|---|---|---|
| PNG | Slides, chats, documents | The diagram as a sharp image, white background |
| SVG | Websites, print, vector editing | Scales to any size; every label stays text |
| Hand-overs and lab reports | The diagram, a device and addressing table, a cable schedule and every device's configuration, via your browser's Save as PDF | |
| TXT | Configuring real gear, change records | Every router, switch, firewall and access point's running-config in one file, with passwords and keys replaced |
| draw.io | Editing in draw.io or diagrams.net | Every device, cable, port label, zone, label, shape and connector, as editable cells |
| CSV | Spreadsheets and label printers | A cable schedule (both ends of every cable) and an addressing table |
| JSON | The NetForge-AI lab | The whole network, ready for the lab's Import |
Draw it, then run it
Most diagram tools draw pictures of networks. Here the drawing is the network: every device is a real simulated device with its real ports, every cable lands on a free port the lab accepts, and every address is configured the way you would configure it by hand. So a diagram can be tested instead of trusted — press Simulate, ping from one PC to another, and you find the wrong gateway or the missing route before anyone builds it.
Drawing has no device limit. Simulating opens the lab, which runs up to 5 devices per topology without a paid plan; to try part of a larger design, select those devices and press Simulate.
New to building networks? The guided builds walk you through a working network one checked step at a time.
Frequently asked questions
Is this network diagram maker really free?
Yes. There is no account, no watermark and no limit on how many devices you draw. Only simulating a diagram in the live lab follows the lab's plan limit: up to 5 devices per topology without a paid plan.
Where is my diagram saved?
In your own browser, on this device. Nothing is uploaded while you draw or export. To keep a copy or move it to another computer, export it as NetForge JSON and open that file here or in the lab.
What does Simulate do?
It opens the same network in the NetForge-AI lab: the same devices, names, cables and addresses, now running on the simulator. You can ping from a PC, watch the packets cross the cables, and keep configuring each device in its console. The lab asks before it replaces anything already on your lab canvas.
Can I keep editing the diagram in draw.io?
Yes. The draw.io export opens in draw.io and diagrams.net with every device, cable, port label, zone and label as an editable shape. For other drawing tools, use the SVG export, which keeps every label as text.
Are the port names and settings real?
They are the simulator's own: the same port numbering, and settings applied by typing the standard interface and host commands, which the properties panel shows you. What you draw is what the lab runs — so a diagram can be checked with a ping instead of trusted on sight.
Does it work on a phone or tablet?
Yes. Tap a device to add it, use Connect and tap two devices to cable them, and pinch to zoom; the properties open as a sheet from the bottom. A bigger screen is easier for large diagrams, and Full screen gives the canvas the whole window.
Can I draw flowcharts, UML or database diagrams too?
Yes. Next to the network devices are eight shape libraries: General, Misc, Advanced, Basic, Arrows, Flowchart (process, decision, data, document, database and the rest), Entity Relation (tables with PK and FK keys, entities, attributes and relationships) and UML (classes, interfaces, packages, components, actors, use cases, states, activities and sequence lifelines). Connectors join them in each notation's style — arrows, UML association, aggregation, composition, generalization and dependency, and crow's-foot one-to-many. Shapes are part of the drawing and every export; Simulate opens only the network in the lab.
What can't it draw?
It draws logical networks — devices, cables, addresses, zones and labels — and general diagrams such as flowcharts, UML and database diagrams. Rack elevations, floor plans and cable lengths are not part of it. Wireless SSIDs and routing protocols are configured in the lab's console after you press Simulate.
Planning the addresses first? Use the subnet calculator or the VLSM planner, then draw the result here.