Open Network Diagram

Open Network Diagram is a self-hosted network mapping and inventory tool for home-lab users who want to keep infrastructure records as structured data. Its combination of topology, IPAM and rack views suits a compact environment, provided you can secure access at the deployment level.

Overview

Rather than keeping infrastructure details in a diagram alone, the application uses JSON as its source of truth. You can back up, reuse and optionally version that data, making it useful as a maintained record of hosts, virtual machines, devices and their relationships. The project is licensed under GNU GPL v3.

Its scope is deliberately centered on network documentation and inventory, rather than broad infrastructure management. That focus makes it a practical fit for a home lab, but the lack of built-in authentication and TLS is a serious limitation for shared or internet-accessible deployments.

Key features

The network view maps topology with Ethernet labels, subnets and VLANs. Hosts & VMs adds machine inventory and service mapping, with expandable VM lists for each machine. Rack view captures managed racks, U positions and equipment height; it also supports side-by-side shelf items and click-through to the editor. These views give a small environment a useful mix of logical and physical context.

The IPAM panel reports subnet utilisation, flags duplicate addresses and suggests the next free IP. That helps with routine address tracking, though it is best understood as part of a documentation tool rather than a standalone network-management system. Cable records can include type, colour and length, with colour-coded connections and hover details to clarify physical links.

In self-hosted mode, changes autosave to JSON, writes persist atomically and rolling backups keep the five latest files. Docker Compose and writable data volumes support deployment; published images support AMD64 and 64-bit ARM, including Raspberry Pi systems. The runtime exposes GET and PUT operations at /api/network-data, and its locally vendored icon catalogue and lack of external API dependencies support offline-friendly use.

Security needs deliberate planning. The project has no authentication or TLS, and topology records may contain host names, addresses, MAC addresses and other sensitive details. Its documentation recommends restricting access to a LAN or VPN, using a firewall, or placing an authenticated TLS-terminating reverse proxy in front. NETWORK_READ_ONLY=true can prevent edits for public demonstrations, but it neither conceals the topology nor authenticates viewers.

Pricing

Open Network Diagram: free. The free plan includes self-hosted Docker deployment under GNU GPL v3, with no separate paid tier described. It is a straightforward choice for users comfortable operating their own deployment; it does not remove the security work that self-hosting entails.

Platforms

Open Network Diagram is available as a web application and API, deployed on a self-hosted Docker setup. Its published images support AMD64 and 64-bit ARM hardware.

Who it's for

Choose it if you run a home lab and want one structured record for network topology, machines, VMs, IP addresses, cabling and rack placement. The JSON model and rolling backups suit users who value portable, locally managed data. It is a poor fit for deployments that require built-in user authentication or encrypted transport without adding infrastructure around the application.

Pros and cons

• Pros: Network, host and rack views bring topology and physical inventory together, including U positions and shelf equipment.
• Pros: IPAM checks duplicate addresses and suggests the next free IP, while reporting subnet utilisation.
• Pros: JSON persistence, atomic writes and five rolling backups help keep the self-hosted record reusable and recoverable.
• Pros: Docker images for AMD64 and 64-bit ARM make deployment possible on common server hardware and Raspberry Pi systems.
• Cons: No built-in authentication or TLS means operators must restrict access or supply a protected proxy themselves.
• Cons: Read-only mode blocks changes but does not hide topology data, so it is not a safe substitute for access control.

Alternatives

For other options, see Network Documentation Software.

• Scanopy is worth considering if you want a freemium alternative with a hosted-platform range spanning Linux, macOS, Windows and web as well as self-hosting; its free Community Edition is limited to one network and one user seat.
• LOGINventory may suit readers prioritizing device inventory: its Forever-Free plan covers up to 20 devices, while Open Network Diagram emphasizes diagrams, IPAM and rack mapping.
• GestióIP is the alternative to consider when IP address management is the primary need; Open Network Diagram combines basic IPAM with topology and inventory views.
• Danbyte is another free, open-source, self-hosted option for readers comparing no-cost tools.
• Nautobot offers an open-source, self-managed Community edition for exploring, initial workflows and limited production deployments.
• Obelinf may appeal if you want a personal plan with stated limits of one user, one organization, one site, four racks and 30 devices.
• ITFlow is a free, open-source self-hosted alternative; hosting and sponsor support are paid services.
• phpIPAM is a free self-hosted option if you want software focused on IP address management.

Verdict

Open Network Diagram is a strong fit for home-lab users who want a free, Docker-based way to maintain network, host and rack records as portable JSON. Its most compelling advantage is the combination of practical mapping views and lightweight IPAM in one self-hosted tool. Look elsewhere—or add a properly secured proxy—if authentication and TLS must be built in rather than managed as part of deployment.