A dynamic IP address is assigned automatically and can change over time, while a static IP address is fixed and stays the same until someone deliberately changes it. Most homes are fine with dynamic addresses; a static IP is mainly worth it if other systems need to find or trust your connection at a known address.
Quick comparison
| Dynamic IP | Static IP | |
|---|---|---|
| How it is assigned | Automatically, usually by DHCP | Manually configured, or permanently reserved by the provider |
| Does it change? | It can, on lease expiry, reboot or network changes | No, unless reconfigured |
| Setup effort | None | Some configuration required |
| Cost (public IP) | Included with most plans | Often an extra charge or business-plan feature |
| Best for | Browsing, streaming, gaming, everyday use | Servers, VPN endpoints, remote access, IP allowlists, email |
It helps to remember that "static or dynamic" applies separately to your public address (assigned by your ISP) and to each device's private address on your home network (assigned by your router). If those terms are unfamiliar, start with Public vs Private IP Addresses Explained.
How dynamic IP addresses work
Dynamic addressing is almost always handled by the Dynamic Host Configuration Protocol (DHCP). When a device joins a network, it goes through a four-step exchange often remembered as DORA:
- Discover: the device broadcasts a request asking whether any DHCP server is available.
- Offer: a DHCP server (your router, at home) offers an unused address from its pool.
- Request: the device asks to use the offered address.
- Acknowledge: the server confirms and records the assignment.
Along with the address, DHCP hands out the subnet mask, the default gateway (your router) and DNS servers. The assignment is a lease with an expiry time. Devices try to renew their lease about halfway through, so in practice a device that stays connected often keeps the same address for a long time. If it is offline when the lease runs out, or the server's pool is reorganised, it may get a different one.
Dynamic public IPs from your ISP
Your ISP uses the same idea on a larger scale to assign your router's public address. How often it changes varies widely between providers. Some keep the same address for months as long as your router stays online; others change it on every reconnection, or on a schedule. Mobile networks tend to change addresses frequently and often place you behind carrier-grade NAT. You can watch for changes by checking your address occasionally on the WhatsMyIPNumber home page.
With IPv6 the ISP typically delegates a whole prefix (often a /56 or /48) rather than a single address. Some ISPs keep that prefix stable; others rotate it, which changes the public IPv6 address of every device in the home.
How static IP addresses work
A static address is simply one that does not change. There are two very different ways to get one, depending on which address you mean.
Static private IP on your home network
For devices such as printers, network storage, home servers or cameras, a fixed local address makes them easier to reach and makes port forwarding rules reliable. You have two options:
- DHCP reservation (recommended): in your router's settings, bind an address to the device's MAC address. The device still uses DHCP, but always receives the same address. Configuration stays in one place, so there is little risk of conflicts. Look for "Address Reservation", "Static Lease" or "DHCP Binding" after you log in to your router.
- Manual configuration on the device: enter the IP address, subnet mask, gateway and DNS servers yourself. Choose an address inside your subnet but outside the router's DHCP pool, or two devices may end up with the same address.
Static public IP from your ISP
A static public address must be provided by your ISP, because only they control which addresses are routed to your connection. Many residential providers do not offer one at all; others offer it as an add-on or include it with business plans. When you get one, the ISP tells you the address (or block of addresses), the gateway and the subnet mask. Some providers configure it automatically through DHCP, while others require you to enter it in your router's WAN settings.
Pros and cons
Advantages of a dynamic IP
- Zero configuration: devices connect and work immediately.
- No extra cost: it is the default on almost every consumer plan.
- Efficient use of addresses: ISPs can reuse scarce IPv4 addresses among customers.
- A small privacy benefit: a changing address makes it slightly harder to link your activity over long periods, although websites have many other ways to recognise you.
Advantages of a static IP
- Reliable inbound access: servers, VPNs, remote desktop and security cameras can always be reached at the same address.
- IP allowlisting: many business systems, cloud firewalls and admin panels only accept connections from approved addresses.
- Email and reputation: running a mail server requires a stable address with matching reverse DNS, which ISPs usually only set up for static addresses.
- Stable DNS records: you can point a domain's A or AAAA record at the address without worrying about it changing.
Drawbacks of a static IP
- Usually costs more, or requires a business plan.
- A permanent public address is a permanent target: anything you expose to the internet will be scanned continuously, so firewalls and updates matter more.
- If the address ends up on a blocklist, you cannot simply reconnect to get a new one.
Which do you need?
You probably do not need a static public IP if you only browse, stream, play games, make video calls or work through your employer's VPN. Dynamic addressing handles all of those.
A static public IP is worth considering if you:
- host a website, game server or mail server from your own connection;
- run a VPN server so you can reach your home or office network remotely;
- need to be allowlisted by a client, bank, cloud provider or SaaS admin console;
- operate business equipment such as VoIP systems or point-of-sale terminals that expect a fixed address.
The middle ground: dynamic DNS
If you only need to find your home connection by name, dynamic DNS (DDNS) is a free or low-cost alternative. A small client on your router or a computer updates a hostname, such as myhome.example-ddns.net, whenever your public IP changes. Many routers have DDNS support built in. DDNS does not help with allowlisting or email reputation, and it will not work if your ISP uses carrier-grade NAT, because you have no public address of your own to point at. Use the open port checker to confirm that inbound connections actually reach you.
Frequently asked questions
How can I tell whether my public IP is static or dynamic?
Your ISP contract or account page will say so; static addresses are almost always an explicit, named feature. You can also note your address on our home page, restart your router, and check again. If it changes, it is definitely dynamic. If it does not, it may still be dynamic with a long lease.
Is a static IP safer than a dynamic one?
Not by itself. Security depends on your firewall, what services you expose and how well they are maintained. A static address simply makes a target easier to find again, so it raises the stakes of poor configuration.
Can I force my dynamic IP to change?
Often, yes: restarting the router or leaving it off for a while may get you a new address, depending on your ISP. Our guide on how to change your IP address covers this and other methods.
Does a VPN give me a static IP?
Usually not. Most VPN services share their exit addresses among many users and may rotate them. Some offer a "dedicated IP" add-on that gives you an address only you use, which can help with allowlisting.