Public vs Private IP Addresses: What's the Difference and How to Tell

If you've ever looked at your network settings and seen an IP address that starts with 192.168 or 10.0, and then looked up your IP online and gotten a completely different number, you've already run into the public vs private IP distinction firsthand. It's one of the most common points of confusion in home networking, and it trips up plenty of IT professionals too when they're working across unfamiliar networks. Here's how to check if an IP is public or private, in any situation, without needing to memorize anything.

The short version

A private IP address only works inside your own network, your home Wi-Fi or office LAN. It's how your laptop, phone, printer, and smart TV all talk to each other and to your router. A public IP address is the one your router uses to talk to the internet, and it's visible to any website or service you connect to. Think of it like an apartment building: your private IP is your unit number, meaningful only inside the building, while the public IP is the building's street address, the one that matters to anyone outside trying to reach you. For the full breakdown of how these two relate to each other and why your device shows one while websites see the other, see our guide on public IP vs local IP address.

How to know if my IP is public or private: check the number range

Private IP addresses always fall into one of these reserved ranges, set aside by international standards specifically so they'd never be handed out on the public internet:

• 10.0.0.0 to 10.255.255.255, common on larger networks and many home routers, this is the largest private block by far
• 172.16.0.0 to 172.31.255.255, often used by businesses and some routers, also the default range Docker containers use internally
• 192.168.0.0 to 192.168.255.255, the most common default range for home Wi-Fi, almost every consumer router ships configured somewhere in this block

If an address falls outside all three of these ranges, it's public. This answers the common question "is 172.22.16.71 public or private" without needing any tool at all, just check whether it lands inside one of the three blocks above. In that specific example, 172.22.16.71 sits inside the 172.16.0.0 to 172.31.255.255 block, so it's private.

Two ranges that trip people up

The three ranges above cover most cases, but two additional ranges cause confusion because they don't behave like typical private addresses:

• 127.0.0.0 to 127.255.255.255 (loopback), this refers to your own device, not a network address at all. If you see 127.0.0.1, that's your computer talking to itself, used constantly by local software and development servers, but it never represents a real network connection to anything else.
• 100.64.0.0 to 100.127.255.255 (CGNAT), used by mobile carriers and some ISPs, technically not the same as a standard private range but functions the same way in practice, your device doesn't have a unique public IP of its own, your ISP is sharing one public IP across many customers.

Use a public or private IP checker instead

If you'd rather skip the manual math, especially when you're dealing with an unfamiliar or oddly formatted address, check yours with our public/private IP checker. Paste in any address and it tells you instantly which category it falls into, including the CGNAT and loopback edge cases above that a simple range check can easily miss if you're doing it by eye.

Why your device might show a private IP even though you're online

This is the part that confuses most people asking how to know if their IP is public or private. Your device's network settings show a private IP because that's the address it uses inside your home network, assigned by your router through DHCP. Your router then uses a separate public IP, assigned by your ISP, to represent your entire network to the internet. Both are correct at the same time, they're just answering different questions: one is your device's address on your local network, the other is your network's address as seen from outside. Every device behind your router shares that single public IP when browsing the internet, which is exactly why your phone, laptop, and smart TV can all show the same public IP when you check it, despite having different private IPs on your home network.

Does it matter which type of IP you have?

For everyday browsing, no. Whether your home network sits behind a public IP directly or behind CGNAT rarely affects normal use like streaming, browsing, or video calls. It starts to matter when you're trying to do something that requires an external device or service to reach into your network directly, hosting a game server, setting up remote access to a security camera, or configuring port forwarding for a specific application. In those cases, knowing exactly what type of IP you're working with up front saves a lot of troubleshooting time later.

Quick reference

Have a specific address you're unsure about? Get an instant answer with the IP checker, no need to keep this table bookmarked for later.