Public vs. Private IP Address: What’s the Difference

Every device on a network needs an IP address to communicate with other devices and services. However, IP addresses are not all used in the same way. Public and private IP addresses serve different purposes depending on whether communication happens over the Internet or within a local network.

A public IP address is used for communication between your network and the Internet, while a private IP address is used to identify individual devices inside a local network. Understanding the difference can help when configuring a network, troubleshooting connectivity, or setting up services that need Internet access.

What Is a Public IP Address?

A public IP address is an Internet-facing address that can be reached over the public Internet. It is generally assigned by an Internet Service Provider (ISP) to a router or directly to an Internet-facing device such as a server.

When devices on a home or office network access the Internet, they commonly share the network’s public IP address. The router uses Network Address Translation (NAT) to manage communication between that public address and the private IP addresses of individual devices.

For example, a laptop may have a private address such as 192.168.1.20, while the router uses a public IP address to communicate with websites and other Internet services.

Public IP addresses are globally unique and can be used for Internet-facing services such as websites, VPN servers, FTP servers, and remote access. Because they are exposed to the Internet, systems using public IP addresses should be protected with appropriate security controls, such as firewalls and restricted network ports.

What Is My Public IP Address?

You can check your public IP address without changing any network settings.

• Open a web browser.
• Search for “What is my IP address?”
• The search results will normally display the public IP address associated with your Internet connection.

The address shown is the public-facing IP visible to websites and other Internet services. Depending on your connection, you may see an IPv4 address, an IPv6 address, or both.

Public IP Ranges

Public IPv4 addresses are globally routable addresses that are not part of the reserved private IPv4 ranges. Unlike private addresses, a public IP address must be globally unique so that Internet traffic can reach the correct destination.

It is generally more useful to identify the reserved private ranges rather than treating every other IPv4 address as a simple public range, because IPv4 also contains special-purpose and reserved address blocks.

What Is a Private IP Address?

A private IP address is used inside a local network such as a home, office, or other private network. A router or DHCP service normally assigns a private IP address to each device connected to the network.

For example, a router might assign:

• Computer: 192.168.1.20
• Printer: 192.168.1.21
• Phone: 192.168.1.22

These devices can communicate with one another using their private IP addresses.

Private IP addresses are not directly routed across the public Internet. When a device needs to access an Internet service, the router normally uses NAT to translate the private address to the network’s public IP address. When the response comes back, the router directs the traffic to the appropriate device using its private IP address.

What Is My Private IP Address?

You can find your private IP address from your device’s network settings.

Windows:

1. Open PowerShell or Command Prompt.
2 Run:
ipconfig

3. Find the active network adapter.
4. Look for IPv4 Address. This is normally the device’s private IPv4 address on the local network.

macOS:

1. Open System Settings or System Preferences, depending on your macOS version.
2. Open Network.
3. Select the active Wi-Fi or Ethernet connection.
4. View the connection details to find the assigned IP address.

Private IP Ranges

There are three reserved private IPv4 address ranges:

These addresses can be reused in different private networks because they are not globally routed on the Internet. For example, your home network and another company’s network can both use 192.168.1.10 without creating a conflict between the two networks.

Difference Between Public and Private IP Addresses

The main difference is where the address can be used and who can reach it.

A public IP address provides Internet-facing connectivity, while a private IP address is used for communication inside a local network. Multiple devices can have different private IP addresses while sharing the same public IP address through NAT.

Category	Public IP Address	Private IP Address
Scope	Global / Internet	Local network
Purpose	Communication with external networks and Internet services	Communication between devices within a private network
Visibility	Visible to Internet services	Normally visible only within the local network
Assignment	Usually assigned by an ISP or hosting/network provider	Usually assigned by a router or DHCP service
Uniqueness	Globally unique	Only needs to be unique within its local network
Address Range	Globally routable addresses, excluding reserved/special ranges	10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16
Example	8.8.8.8	192.168.1.20
Internet Access	Can communicate directly over the public Internet when properly configured	Normally requires NAT or another routing mechanism to access the Internet
Security Exposure	More exposed to Internet-based traffic	Usually less exposed because it is not directly Internet-routable

How to Change Public IP Address

Your ISP normally controls the public IP address assigned to your Internet connection, so you cannot manually change it in the same way you can change a device’s private IP.

Depending on your ISP and connection type, you may receive a different public IP by:

• Reconnecting your Internet connection.
• Connecting to another network.
• Switching from Wi-Fi to mobile data.
• Requesting a different IP from your ISP.
• Using a VPN, which makes websites see the VPN server’s public IP instead of your normal public IP.
• Using a proxy or Tor in situations where those options are appropriate.

If you require an IP address that remains fixed, you can ask your ISP or hosting provider about a static public IP.

Does My Private IP Address Change?

Yes. A private IP address can change when your device reconnects to the network, particularly when the address is assigned automatically through DHCP.

For example, a router might assign 192.168.1.20 to a laptop during one connection and assign another available private address after the device reconnects.

If a device needs to keep the same local address, the network administrator can configure a DHCP reservation or assign a static private IP, depending on the network setup.

How Do I Change My Private IP Address?

On Windows, you can request a new DHCP-assigned private IP address from the router.

1. Open PowerShell or Command Prompt as an administrator.
2. Release the current address:
ipconfig /release

3. Request a new address:
ipconfig /renew

The DHCP server may assign a different private IP address. Whether the address actually changes depends on the network’s DHCP configuration.

On macOS, you can renew the DHCP lease from the network settings:

• Open System Settings or System Preferences.
• Go to Network.
• Select your active connection.
• Open the TCP/IP settings.
• Select Renew DHCP Lease, where available.

The exact menu names may vary between macOS versions.

You can also change the local network configuration from the router’s administration interface, depending on the router model and network setup.

Why Do We Need a Private IP Address?

Private IP addresses allow multiple devices on the same network to communicate without requiring a separate public IP address for every device.

They also help conserve the available IPv4 address space. A home network, for example, can have many devices with private addresses while those devices share the network’s public IP address when accessing the Internet.

Private addresses also reduce direct Internet exposure because they are not normally routable from the public Internet. However, a private IP address should not be considered a complete security solution. Firewalls, authentication, updates, and other security controls are still important.

Why Do We Need a Public IP Address?

A public IP address allows a network or Internet-facing device to communicate with systems outside the local network.

For example, when you open a website, your request needs a routable Internet-facing address so the remote service can return the requested data. Similarly, servers that need to provide services directly over the Internet may require a public IP address.

A typical home or office network does not require every device to have its own public IP. Instead, the router can use NAT so multiple private devices share one public IP.

Who Can See My IP?

Websites and other Internet services can see the public IP address from which your connection reaches them. A public IP can generally be associated with an ISP and an approximate geographic area.

Your private IP address is different. It is normally used only inside your local network and is not directly visible to websites on the public Internet. Devices on the same local network may be able to see one another’s private addresses.

What Information Can Be Obtained from an IP Address?

An IP address can provide information such as the associated ISP and an approximate geographic location. It does not normally reveal your exact home address, phone number, or other personal details by itself.

The information that can be associated with an IP depends on the ISP, available geolocation data, and other information that may be collected alongside the connection.

Does the IP Address Change with Wi-Fi?

It can. When you connect your device to a different Wi-Fi network, the device normally receives a private IP address from the new network. The public IP may also change because the new Wi-Fi network can use a different Internet connection and public IP address.

For example, your laptop may have one private IP address while connected to your home Wi-Fi and receive a different private IP after connecting to an office network.

Can You Hide a Private IP Address?

A private IP address is not normally visible to websites on the public Internet. It is used within the local network. If your goal is to hide your public IP address from websites, services such as VPNs and proxy servers can make the connection appear to originate from another public IP address. Tor can also route traffic through its network, although it may affect connection speed.

Within a local network, other connected devices may still be able to see or communicate with a device’s private IP depending on the network configuration and security settings.

FAQs About Public and Private IP Addresses

1. Public IP Address vs. External IP Address
   Public IP address and external IP address generally mean the same thing. Both refer to the Internet-facing IP address used for communication outside a local network. A public IP can also be described as an outward-facing IP address.
2. Private vs. Local vs. Internal IP Addresses
   The terms private IP, local IP, and internal IP are commonly used to describe an IP address assigned within a private network.
   For example, a local router may assign 192.168.1.25 to a computer. The address allows that computer to communicate with other devices on the same network but is not directly routable across the public Internet.
3. Private vs. Local vs. Internal IP Addresses
   The terms private IP, local IP, and internal IP are commonly used to describe an IP address assigned within a private network.
   For example, a local router may assign 192.168.1.25 to a computer. The address allows that computer to communicate with other devices on the same network but is not directly routable across the public Internet.

Conclusion

Public and private IP addresses work together to handle network communication at different levels. A public IP address provides Internet-facing connectivity, while a private IP address identifies devices within a local network.

In a typical home or office network, multiple devices can use private IP addresses and share a public IP through NAT. The three main private IPv4 ranges are 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16.

Understanding how these addresses work makes it easier to troubleshoot network problems, configure routers, manage servers, and configure VPS Hosting with the right public and private IP addresses.

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