Device42 vs Open Network Diagram

Device42 provides agentless discovery, asset management, and dependency mapping for data center, cloud, and hybrid IT environments. Its scope includes CMDB, DCIM, ITAM, IPAM, password management, and application dependency mapping, in a self-hosted deployment. It can discover network devices through SNMP and cloud resources across AWS, Azure, Google Cloud, Oracle Cloud, and OpenStack.

For data centers, its visual models cover buildings, rooms, racks, cabling, and patch panels, with power and temperature heat maps. Core includes discovery, inventory and asset management, integrations, REST APIs and webhooks, warranty and SSL certificate management, cable and password management, and IPAM. Device42 also tracks software licenses, contracts, and barcodes, and lists more than 30 integrations. Licenses count devices with IP addresses; non-IP assets do not count, and user seats are unlimited. If the device limit is exceeded, the software keeps running but stops collecting additional information until the license is increased. Pricing is available on request, and a free trial is offered.

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.