Open Network Diagram
github.com
What it is
Open Network Diagram is a free, self-hosted tool for visualizing and managing home lab and network architecture. It provides network, Hosts & VMs, and rack views for mapping topology and inventory, including subnets, VLANs, virtual machines and rack positions. Connections can record cable type, colour and length. Its IPAM panel reports subnet utilization, detects duplicate addresses and suggests the next free IP. The application keeps JSON as its source of truth; self-hosted changes autosave, writes are persisted atomically, and rolling backups retain the last five files. Deployment is Docker-first, with writable data volumes and Docker Compose support. The runtime exposes GET and PUT operations at /api/network-data, and published Docker images support AMD64 and 64-bit ARM, including Raspberry Pi systems. The project is licensed under GNU GPL v3 and has no runtime dependency on external APIs. It does not include authentication or TLS. The project warns that topology details may expose sensitive infrastructure information and advises restricting access or using an authenticated TLS-terminating reverse proxy.
Spec sheet
- Purpose
- Open Network Diagram is a declarative, self-hosted tool for visualising and managing home lab and network architecture diagrams.Read 2 Oct 2026 · github.com
- Audience
- The project is positioned for home lab users who need an up-to-date map of machines, virtual machines, devices and rack placement.Read 1 Oct 2026 · github.com
- Platforms
- Published Docker images support AMD64 and 64-bit ARM, including Raspberry Pi systems.Read 1 Oct 2026 · github.com
- Deployment
- The project provides Docker and Docker Compose deployment instructions with writable data volume support.Read 2 Oct 2026 · github.com
- API
- The documented runtime API endpoint is GET/PUT /api/network-data.Read 2 Oct 2026 · github.com
- Integrations
- The project says it has no runtime dependency on external APIs and includes a locally vendored icon catalog for offline-friendly behavior.Read 2 Oct 2026 · github.com
- Security
- Open Network Diagram does not include authentication or TLS.Read 1 Oct 2026 · github.com
- License
- The repository identifies the software as GNU GPL v3 licensed.Read 2 Oct 2026 · github.com
- Cabling
- Connections can track cable type, colour and length with colour-coded links and hover details.Read 1 Oct 2026 · github.com
- Data model
- The application keeps a JSON source of truth that can be backed up, reused and optionally versioned.Read 1 Oct 2026 · github.com
- IPAM
- The IPAM panel shows per-subnet utilization, detects duplicate IP conflicts, and suggests the next free IP when adding machines, devices, or VMs.Read 2 Oct 2026 · github.com
- JSON source of truth
- The app documents infrastructure in a visual UI while keeping a JSON source of truth that users can back up, reuse, and optionally version after reviewing for sensitive information.Read 2 Oct 2026 · github.com
- Network and host views
- It provides a network view with Ethernet labels and a Hosts & VMs view for inventory and service mapping.Read 2 Oct 2026 · github.com
- Persistence
- Self-hosted mode autosaves JSON data and keeps the last five rolling backups.Read 1 Oct 2026 · github.com
- Persistence and backups
- In self-hosted mode, changes autosave to JSON, writes are persisted atomically, and rolling backups retain the last five files.Read 2 Oct 2026 · github.com
- Rack inventory
- Rack view supports managed racks with U positions and heights, side-by-side shelf items, and click-through to the editor.Read 2 Oct 2026 · github.com
- Read-only mode
- Optional read-only mode prevents changes and is offered for public demonstrations and sharing.Read 2 Oct 2026 · github.com
- Security limit
- The README advises against exposing a writable deployment directly to the internet and recommends a firewall, LAN or VPN, or an authenticated TLS-terminating reverse proxy.Read 1 Oct 2026 · github.com
- Security limitation
- The project does not include authentication or TLS, and its documentation advises restricting access or using an authenticated reverse proxy that terminates TLS.Read 2 Oct 2026 · github.com
- Sensitive data
- The project notes that topology data may expose host names, addresses, MAC addresses, and other sensitive infrastructure details.Read 2 Oct 2026 · github.com
- Supported image architectures
- Published Docker images support AMD64 and 64-bit ARM, including Raspberry Pi systems.Read 2 Oct 2026 · github.com
- Topology details
- Users can declare subnets and VLANs, track cable type, colour, and length, and expand VM lists per machine.Read 2 Oct 2026 · github.com
- Views
- It provides network, Hosts & VMs, and rack views for infrastructure inventory and topology mapping.Read 1 Oct 2026 · github.com
Plans and prices
Open Network Diagram Free Self-hosted · Docker deployment · GNU GPL v3 Read 2 Oct 2026 · github.com
Strong points and limits
Strong points
- Provides network, Hosts & VMs, and rack views.
- IPAM detects duplicate addresses and suggests a free IP.
- Self-hosted changes autosave with five rolling backups.
- Docker images support AMD64 and 64-bit ARM.
- Free under GNU GPL v3.
Limits
- Does not include authentication or TLS.
- Topology data may expose sensitive infrastructure details.
- Writable public deployments need access restrictions.
Who it suits
Open Network Diagram suits home lab users who want a self-hosted map of hosts, virtual machines, devices and rack placement. It is a poor fit for an internet-exposed writable deployment without separate access protection.
Verdict
The tool combines visual infrastructure views, IPAM and JSON-based persistence in a free, self-hosted package. Its lack of built-in authentication and TLS makes deployment access controls essential.
Where Specifiction places it
- Network Documentation Software#12 of 278.1
