Every device connected to a network uses IP addressing to communicate with other devices and services. However, not all IP addresses serve the same purpose. Some are designed for communication across the public internet, while others are used inside private networks such as homes, offices, and businesses.
This is where public IP addresses and private IP addresses come in. Although both are important for networking, they work differently and are used in different situations.
Understanding the difference between a public IP address and a private IP address can help you troubleshoot internet problems, configure your router, manage a local network, and understand how devices communicate over the internet.
In this guide, we will explain the differences between public and private IP addresses with practical examples.
What Is a Public IP Address?
A public IP address is an IP address intended to be globally routable across the public internet. It allows networks and internet-facing services to exchange data with other networks around the world, subject to routing and security policies.
Public IP addresses are commonly associated with internet connections, web servers, hosting services, and other online systems.
For example, 8.8.8.8 is a public IPv4 address used by Google Public DNS.
In a typical home network, your internet service provider (ISP) may assign a public IPv4 address to your router’s WAN interface. Your router can then use Network Address Translation (NAT) to allow multiple devices with private IP addresses to share that public IPv4 address.
However, not every internet connection has a public IPv4 address directly assigned to the customer’s router. Some ISPs use Carrier-Grade NAT (CGNAT), which allows multiple customers to share public IPv4 addresses.
To learn more, read our guide on What Is a Public IP Address?
What Is a Private IP Address?
A private IP address is an IP address used within a private network, such as a home Wi-Fi network, office LAN, or business network. Private IPv4 addresses are not ordinarily routed across the public internet.
For example, your router might assign the following addresses to devices connected to your home network:
- Laptop:
192.168.1.10 - Smartphone:
192.168.1.11 - Smart TV:
192.168.1.12 - Network printer:
192.168.1.13
These devices can communicate with one another when they are on compatible networks and the necessary access permissions are in place.
The three private IPv4 address ranges defined by RFC 1918 are:
| Private IPv4 Range | CIDR Notation |
|---|---|
10.0.0.0 – 10.255.255.255 | 10.0.0.0/8 |
172.16.0.0 – 172.31.255.255 | 172.16.0.0/12 |
192.168.0.0 – 192.168.255.255 | 192.168.0.0/16 |
These addresses can be reused on separate private networks. For example, two households can both use 192.168.1.10 for their laptops without causing an IP address conflict between those separate networks.
For more details, see our guide on What Is a Private IP Address?
Public IP vs. Private IP: Key Differences
The main difference between a public IP address and a private IP address is how each is used and routed.
A public IP address is intended for communication across the public internet, while a private IP address is used for communication within private networks.
The following table summarizes the key differences.
| Feature | Public IP Address | Private IP Address |
|---|---|---|
| Primary purpose | Communication across the public internet | Communication within private networks |
| Internet routing | Globally routable when properly assigned and configured | Not ordinarily routed across the public internet |
| Uniqueness | Globally coordinated within the applicable address system | Can be reused on separate networks |
| Common IPv4 examples | 8.8.8.8, 1.1.1.1 | 192.168.1.10, 10.0.0.5 |
| Assignment | ISP, hosting provider, or network administrator | Router, DHCP server, or network administrator |
| Typical use | Internet-facing services and network connectivity | Home, office, and internal network communication |
| Direct remote access | Depends on routing, firewall rules, and service configuration | Usually requires a VPN, gateway, or another access method from outside the network |
| Address availability | Public IPv4 addresses are limited | RFC 1918 IPv4 addresses can be reused on separate networks |
| Security | Requires suitable security controls | Offers no automatic protection against other devices on the local network |
One important point: a public IP address does not automatically make a device accessible from anywhere, and a private IP address does not mean that remote access is impossible. Network configuration, routing, firewall rules, and access methods determine what can communicate with what.
Examples of Public and Private IP Addresses
Looking at practical examples is one of the easiest ways to understand the difference.
Example 1: A Home Wi-Fi Network
Suppose you have a home internet connection with a router.
Your router’s WAN interface has a public IPv4 address assigned by your ISP, while your laptop and smartphone use private IP addresses on the local network.
For example:
- Router WAN IPv4:
203.0.113.25(documentation example only) - Router LAN IP:
192.168.1.1 - Laptop IP:
192.168.1.10 - Smartphone IP:
192.168.1.11
Here, the WAN address represents the public-facing side of the connection in this simplified example. The LAN addresses allow devices to communicate inside the home network.
The address 203.0.113.25 belongs to a range reserved for documentation, so it is an example rather than a real public address for an internet connection.
When the laptop opens a website, the router may translate the laptop’s private source address to its public IPv4 address using NAT. The website generally sees the public source address used by the connection rather than the laptop’s private LAN address.
Example 2: An Office Network
An office may have dozens or hundreds of computers, printers, servers, and other network devices.
The organization can assign private IP addresses to its internal devices and use a public IP address for internet connectivity.
For example:
- Office gateway:
192.168.10.1 - Employee computer:
192.168.10.20 - Office printer:
192.168.10.30 - Internal file server:
192.168.10.40
These addresses can be used for internal communication according to the network’s subnet and security configuration.
The organization does not need a separate public IPv4 address for every internal device. Its gateway can use NAT to provide internet access, while firewall rules control incoming and outgoing connections.
Example 3: A CCTV Camera and NVR System
Private IP addresses are commonly used for IP cameras and network video recorders.
For example, a CCTV network might have an NVR at 192.168.20.10 and cameras at 192.168.20.11, 192.168.20.12, and 192.168.20.13.
The NVR can communicate with the cameras over the local network when the addresses, routing, and camera settings are configured correctly.
If an administrator needs remote access, a VPN or another secure remote-access method can provide a path into the network. A public IP address alone does not automatically make the NVR or cameras accessible from the internet.
How Do Public and Private IP Addresses Work Together?
Public and private IP addresses are often used together in the same network.
Consider a typical home internet connection:
- Your ISP provides internet connectivity to your router.
- Your router has an upstream IP address, which may be public or may be part of a private or shared-address network operated by the ISP.
- The router assigns private IP addresses to devices on the home LAN.
- Your laptop sends internet-bound traffic through its default gateway.
- If NAT is configured, the router translates the outgoing IPv4 source address as necessary.
- The response returns through the network, and the router forwards it to the appropriate device.
This arrangement allows several devices to share a public IPv4 address.
However, if the ISP uses CGNAT, the router may not have a public IPv4 address directly assigned to its WAN interface. The ISP performs another layer of address translation upstream.
With IPv6, devices may use globally routable IPv6 addresses without relying on the same form of NAT commonly used for IPv4. Firewall rules and other security controls are still essential.
Which Is Better: Public IP or Private IP?
Neither is universally better. Public and private IP addresses are designed for different purposes, so the appropriate choice depends on what you are trying to accomplish.
When Should You Use a Private IP Address?
Private IP addressing is suitable when you need to connect devices inside a home, office, or business network.
Common examples include:
- Connecting computers and smartphones to a local network.
- Managing printers and shared storage.
- Connecting IP cameras to an NVR.
- Running internal servers and applications.
- Organizing networks with subnets and VLANs.
- Allowing multiple devices to share an internet connection.
Private IPv4 addressing is especially useful when devices do not need to be directly reachable through the public internet.
When Is a Public IP Address Needed?
A public IP address may be required when a service needs a globally routable endpoint or when a network requires a stable public address for specific connectivity arrangements.
Common examples include:
- Hosting a website or public-facing service.
- Operating certain VPN endpoints.
- Receiving direct incoming connections.
- Supporting particular remote-access configurations.
- Hosting services that require a reachable public IPv4 address.
A public IP address is not always necessary for remote access. VPN providers, reverse proxies, relay services, and other solutions can provide connectivity in different network environments.
Can a Private IP Address Access the Internet?
Yes. A device with a private IP address can access the internet through a router or gateway when the network is configured to provide that connectivity.
For example, a laptop with the address 192.168.1.10 can browse websites through a home router. The laptop does not need its own public IPv4 address.
For IPv4, the router commonly uses NAT to translate traffic between the private network and the upstream network.
Therefore, private IP addresses are not limited to offline networks. They are widely used in networks that have full internet access.
Can Someone Access My Private IP Address from the Internet?
A private IPv4 address is not directly reachable through ordinary public internet routing. However, authorized remote access can still be possible through a VPN, configured gateway, reverse proxy, or another suitable connection method.
For example, a network administrator can set up a VPN so that an authorized employee can access an internal server using its private IP address.
Also, a device using a private IP address is not automatically protected from threats originating inside its local network. Proper firewall rules, authentication, updates, and network segmentation remain important.
How Can You Check Whether Your IP Address Is Public or Private?
You can check the IP address assigned to your device or router and compare it with the reserved ranges.
For private IPv4 addresses, check whether the address falls within one of these ranges:
10.0.0.0/8172.16.0.0/12192.168.0.0/16
On Windows, open Command Prompt and run:
ipconfig
Look for the IPv4 Address entry under the active network adapter. This normally shows your device’s local address, not necessarily your public IP address.
To check the public-facing address, use a trusted online IP lookup service. You can also sign in to your router and inspect its WAN status.
If the router’s WAN IPv4 address differs from the address shown by the lookup service, your connection may involve CGNAT, another upstream NAT device, or a different routing arrangement.
Keep in mind that an address outside the RFC 1918 ranges is not automatically a public address. Other IPv4 ranges are reserved for special purposes, and some are not globally routable.
Frequently Asked Questions (FAQs)
1. What is the main difference between public IP and private IP?
A public IP address is intended for routing across the public internet, while a private IP address is used within private networks and is not ordinarily routed across the public internet.
2. Can two devices have the same private IP address?
Yes, if the devices are on separate networks, they can use the same private IP address without a conflict between those networks. However, two devices using the same address on the same network can cause an IP address conflict.
3. Does every device need a public IP address?
No. Many devices use private IP addresses and share an upstream public IPv4 address through NAT. IPv6 networks can use globally routable addresses for individual devices, depending on the configuration.
4. Is a private IP address safer than a public IP address?
Private addressing reduces direct reachability through ordinary public internet routing, but it does not guarantee security. Devices still need appropriate firewall rules, updates, authentication, and access controls.
5. Can I access my CCTV system using a private IP address?
Yes, if your computer or viewing device has network connectivity to the CCTV system. For access from outside the local network, you will generally need a VPN or another properly configured remote-access method.
6. Why does my router show a private IP address on its WAN interface?
Your ISP may be using CGNAT or another upstream network arrangement. If the WAN address is in 100.64.0.0/10, it is within the shared IPv4 address range commonly used for CGNAT. An address in an RFC 1918 range can also indicate upstream private addressing.
7. Can a public IP address change?
Yes. A dynamic public IP address may change when the ISP renews an assignment or changes its network configuration. A static public IP address is intended to remain consistent, subject to the provider’s service and configuration.
Conclusion
Public IP addresses and private IP addresses are both essential parts of modern networking, but they serve different purposes.
A public IP address provides a globally routable endpoint for internet communication when it is properly assigned and configured. A private IP address allows devices to communicate within a private network without requiring every device to have its own public IPv4 address.
For most home and office networks, the two work together: devices use private IP addresses internally, while a router or upstream gateway handles internet connectivity.
Once you understand this distinction, it becomes much easier to troubleshoot network problems, configure routers, manage CCTV systems, and decide when a public IP address or a secure remote-access solution is necessary.
