EVE-NG vs GNS3: which network emulator to use in 2026

EVE-NG and GNS3 run the same kinds of network images, so the choice comes down to how you want to work and what you can spend. This page compares them on cost, hardware, what they run and daily use, with facts from each project's own site and docs as of October 2026.

The short verdict

• Pick GNS3 if you want a free tool with no node limit, a desktop GUI and the widest choice of emulators, and you are happy to set up the GNS3 VM.
• Pick EVE-NG if you want one lab server that you and others reach from a browser, and a 7-node free tier or a paid licence fits your labs.

Both are good tools. Many people learn on one and use the other at work.

At a glance

Cost and licensing

GNS3 is free and open source under GPL-3.0. There is no paid tier and no node limit. The 2.2 branch is the long-running stable line; 3.0 adds a new server API and web UI, and 3.1 is in alpha.

EVE-NG changed its editions in 2026. The download page lists Community Edition 6.2.0-4 as end of support and end of life in June 2026. The current Professional build runs as Freemium until you add a licence. The comparison page lists:

• Freemium: free, 7 running nodes per EVE instance, admin role only.
• Base: 150 EUR, up to 1024 nodes per lab, admin role only.
• RBL: 150 EUR plus added roles, for admins, editors and lab users.

The EVE-NG cookbook says licences are an annual subscription and that the Professional build needs internet access and working DNS to get updates and validate its licence. Freemium has the same feature list as the paid editions. Only the node count and roles differ.

Seven nodes is enough for most single-topic labs: a few routers, a switch and two hosts. A full CCNP-style topology will hit the limit quickly.

Installation and hardware

GNS3

GNS3 installs as a desktop app on Windows, macOS or Linux. On Linux, the server can run the nodes directly. On Windows and macOS, modern images such as IOSv, IOU and ASAv run inside the GNS3 VM. GNS3 recommends VMware for it because VMware supports nested virtualization, and some images are too slow in VirtualBox. You can also point the GUI at a remote GNS3 server.

Most first-day problems live here: the VM version must match the app, KVM must be visible inside the VM, and Hyper-V can get in the way on Windows. Our GNS3 troubleshooting guide covers each one.

EVE-NG

EVE-NG is a full server based on Ubuntu 24.04 LTS, installed from an ISO. The EVE-NG Professional cookbook calls a bare metal install "the most recommended method". It also supports VMware Workstation Pro 16 or later, ESXi 6.7 or later and Google Cloud. Inside a VM, every lab node is nested, which the cookbook says degrades performance but is fine for labs.

The cookbook's minimum for a laptop or desktop is an Intel i7 with 8 logical processors and 16 GB of RAM, in VMware Workstation. It gives rough sizes for that machine: up to about 30 IOL nodes, 8 to 10 vIOS nodes, or 2 to 3 CSR 1000v nodes per lab. It lists AMD Ryzen desktops as supported, and VirtualBox, Hyper-V and Apple M series Macs as not officially supported.

The upside of a server is that you install it once. After that, any machine with a browser is a client.

What each one runs

Both tools run the images most people need for Cisco and multi-vendor study:

• IOL/IOU: Cisco's Linux-based IOS, light enough to run dozens of nodes.
• Dynamips: emulates old Cisco router hardware to run classic IOS images.
• QEMU/KVM: full VMs such as IOSv, CSR 1000v, Catalyst 8000v, vEOS, vMX or Linux. These need hardware virtualization.
• Docker containers: Linux hosts, tools and container network OSes.

GNS3 also drives VirtualBox and VMware VMs directly, which helps if you already have VMs built there. GNS3 runs Docker nodes on Linux only, so on Windows and macOS they run in the GNS3 VM.

Neither tool ships vendor images. GNS3 offers appliance files that describe how to run an image and which files it needs. You still supply the image. The same goes for EVE-NG. Be careful with licences: Cisco's CML-Free page says the images that come with Cisco Modeling Labs are only licensed for use within CML. Using them in GNS3 or EVE-NG needs a licence that covers that use.

Day-to-day use

Building labs

In GNS3 you drag devices onto a canvas in the desktop app, draw links and open consoles in your terminal. The web UI offers the same in a browser. Projects are .gns3 files, which are JSON, and the server has a REST API for scripting.

In EVE-NG you do the same in the browser. Consoles open either as HTML5 consoles in the browser or as native telnet, VNC and RDP clients on your machine. Labs can be exported and imported. The browser UI means nothing to install on the client, which is handy in a classroom.

Several users

EVE-NG is built for shared servers. Every edition supports accounts; the cookbook says the number of simultaneous web sessions per role depends on your licence, and RBL adds editor and user roles with per-folder locks. That is why trainers and teams often choose it.

GNS3 is mostly used as a single-user desktop tool, but several people can share one GNS3 server. The 3.0 server adds users, groups, roles and access control lists.

Link conditions and capture

GNS3 has packet filters on each link: delay and jitter, random packet loss, frequency drop, corruption and BPF filters, and you can combine them. You can also suspend a link to simulate an outage, and start a Wireshark capture on any link.

EVE-NG lists link quality settings (delay, jitter, packet loss) in every edition, along with hot links between running nodes and integrated Wireshark capture.

Which to pick

• You study alone on a laptop and want no limits or costs: GNS3.
• You have a spare x86 server or a home lab host: EVE-NG Freemium is worth a try, and its browser UI works from any device.
• You run a class or a team lab: EVE-NG with RBL, or one GNS3 server if you don't need roles.
• Your labs are larger than 7 nodes and you don't want to pay: GNS3.
• You use an Apple Silicon Mac: neither runs x86 images well on it. Run either one on a separate x86 machine. Our GNS3 on Apple Silicon post explains what does work.

If neither fits, the GNS3 alternatives overview covers Containerlab, CML, Kathará and netlab too.

Where Isothrum fits

Isothrum's editor is a free browser editor that needs no account; its engine runs locally as WebAssembly. It opens GNS3 projects (.gns3), so you can take an existing topology, keep the drawing, and export it as isoloom.yml plus Docker Compose, Vagrant, Proxmox, Kubernetes or cloud files. Cisco routers come from your own images (IOL, IOSv, CSR 1000v, Catalyst 8000v or Dynamips, built with vrnetlab), or you use FRR. The editor does not run labs itself: you run the exported files with those tools, and a desktop app that runs labs locally is coming soon.