NAT type test
Find out whether your router's NAT is open, moderate or strict — the setting that decides whether you can host game sessions, hear everyone in voice chat and connect to other players directly — and what to change if it is not open.
- Xbox
- —
- PlayStation
- —
- PC / Switch
- —
| Check | Result | Detail |
|---|---|---|
| UDP to our STUN server | Waiting | |
| Public UDP address | Waiting | |
| Mapping behavior | Waiting | |
| Port preserved | Waiting | |
| NAT present | Waiting | |
| Carrier-grade NAT | Waiting | |
| Filtering behavior | Not measurable | Open versus moderate (who may send packets to your mapped port) needs a packet sent from a second server address, which a browser cannot request. Consoles measure it; we cannot. |
1. Enable UPnP on the router: consoles and most games use it to open their ports automatically.
2. Or forward the game's ports to the console's fixed local address (DHCP reservation), then verify with the port checker. Open port checker
3. Make sure only one device does NAT: bridge the provider's modem-router or put the second router in access-point mode.
4. If the router's WAN address is in 100.64.0.0/10 or differs from your public address, the provider's CGNAT is in the way: ask for a public IPv4, use IPv6, or a VPN with port forwarding. Check for CGNAT
Browser approximation of what consoles measure: it sees UDP mapping through our own STUN server (never a third party's), not game-specific rules. What NAT is
Your NAT type
The test asks our STUN server how your connection maps addresses and ports from several angles and classifies the result. It is a WebRTC-based approximation of what consoles and games measure: it can tell endpoint-independent (open-style) from address- or port-dependent (strict-style) mapping, and it detects carrier-grade NAT; it cannot see game-specific port rules.
Open (Type 1)
Your device has a public address or a NAT that maps ports consistently and accepts inbound packets: you can host and connect to anyone.
Moderate (Type 2)
Ports are mapped consistently but inbound connections are only allowed from addresses you have already contacted: you can connect to most players and host for some.
Strict (Type 3)
The mapping changes per destination (symmetric NAT) or inbound is blocked: you can only connect to players with open NAT, and you cannot host.
What your NAT type means for gaming
Games and consoles connect players to each other directly whenever they can. Two strict NATs cannot connect at all; strict plus moderate often fails; open connects to everything. The symptoms of strict NAT are empty lobbies, failed invites, missing voices in party chat and being unable to host. Being behind carrier-grade NAT shows as strict no matter what the router does.
How to change NAT type to open
In order: enable UPnP on the router (consoles and most games use it to open ports automatically); if that is not enough or you prefer not to, forward the game's ports to the console's fixed local address; make sure there is only one router doing NAT (bridge the ISP modem or the second router); and if the router's WAN address is in 100.64.0.0/10 or differs from the address on our homepage, ask the provider for a public address or use IPv6.
Port forwarding and UPnP
UPnP lets devices ask the router for a port mapping; it is convenient and the reason most consoles get moderate or open NAT without configuration. Manual forwarding does the same for the ports the game documents and is the safer choice on a network with many devices. Verify with the open port checker.
CGNAT
If your provider shares one public address among customers, no router setting can make inbound connections work; the result here is strict and the CGNAT check confirms it. Options: a public address from the provider (often available on request or for a small fee), IPv6 (games and consoles increasingly support it), or a VPN with port forwarding.
Frequently asked questions
What is NAT type 2?
Moderate: your router maps ports consistently but only accepts inbound packets from addresses you contacted first. Most players can connect to you; some with strict NAT cannot.
How do I check my NAT type?
Run the test on this page from a device on the same network, or check the console's own network test (PlayStation shows NAT Type 1–3; Xbox shows Open/Moderate/Strict in network settings).
What NAT type is best for gaming?
Open. It connects to everyone and lets you host. Moderate is acceptable; strict is the one to fix.
How to change NAT type from strict to open?
Enable UPnP or forward the game's ports to a fixed local address, remove double NAT by bridging the modem, and if you are behind carrier-grade NAT, get a public address or IPv6 from your provider.
WebRTC ICE gathering against stun.checkmyip.com only; candidates stay in your browser and nothing is stored. Mapping behavior follows RFC 4787 terminology (endpoint-independent vs address-and-port-dependent).