Static IP vs dynamic IP: what is the difference?
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A static IP is a fixed public IP address that does not change when you restart your modem. A dynamic IP is assigned automatically by your internet provider and can change every time you reconnect. Most home and mobile connections use dynamic IPs; you need a static IP to run a server, to be whitelisted, or to have accounts always log in from the same IP.
What is a static IP?
A static IP is an address reserved for one subscriber or server that does not change over time. The internet or infrastructure provider assigns it once, and every connection you make to the internet carries that same address.
Because the address never changes, others can connect to you through it (a website, a camera, a game server), and services can trust it through a whitelist.
What is a dynamic IP?
A dynamic IP is assigned automatically from the provider's address pool, usually over DHCP or PPPoE. When the modem restarts, the connection drops or the lease expires, you may get a different address. 4G/5G networks change IPs even more often.
Many providers also use CGNAT: many subscribers reach the internet through one shared public IP. The IP websites see is then not yours alone, and you cannot accept incoming connections.
Static IP vs dynamic IP comparison table
| Static IP | Dynamic IP | |
|---|---|---|
| Address | Fixed | Can change when you reconnect |
| How it is assigned | Reserved for you | Automatically from the provider's pool |
| Incoming connections | Possible, with open ports | Hard, especially behind CGNAT |
| Shared with others | No | Possibly, when the provider uses CGNAT |
| IP whitelists | Work long term | Need updating every time the IP changes |
| Cost | Usually a paid add-on | Included in the plan |
| Common on | Servers, offices, static proxies | Home and mobile connections |
How to tell whether your IP is static or dynamic
- Open What is my IP and note your public IP.
- Restart your modem, wait for the connection, then check again. A different IP means you have a dynamic IP.
- In the modem's admin page, compare the WAN IP with the one you just saw. If they differ, or the WAN IP is in the
100.64.0.0/10range, your connection goes through CGNAT. - Look the address up in the IP lookup tool to see which provider and ASN own it.
When you need a static IP
- Running a website, game server, NAS or camera that you reach remotely.
- Logging in to systems that only allow a list of IPs (a whitelist), such as admin panels or partner APIs.
- Managing social media, ad or shop accounts that need stable logins from the same place. See running multiple accounts.
- Sending email from your own server, where reputation is tied to the IP address.
How to get a static IP
Order a static IP from your internet provider. Many providers sell static IPs with business internet plans. It is the only option if you need to accept incoming connections on your own line.
Rent a static proxy. A static proxy gives the software you configure a fixed outgoing IP in the country you choose, without changing your internet plan. Note the limit: a proxy only changes the IP of outgoing connections; it does not let you host a server that accepts incoming connections the way a provider's static IP does.
Static residential (ISP) IPs and static datacenter IPs
Static proxies come from two IP sources. ISP IPs are registered to consumer internet providers, so lookup tools show a carrier name instead of a hosting company. Datacenter IPs belong to infrastructure providers; they are cheaper and fast, which suits tools and scraping. Details are in ISP vs datacenter vs residential.
VinaProxy has static ISP proxies in the United States and Vietnam, and private IPv4 proxies in 7 countries. The IP stays the same for the whole rental. For a comparison with proxies that change IP constantly, read static vs rotating proxies.
Frequently asked questions
Is a static IP safer than a dynamic IP?
Not automatically. A static IP is easier to scan over time because the address never changes, so devices on it need a firewall and strong passwords. The benefit of a static IP is stability, not security.
How often does a dynamic IP change?
It depends on the provider. Some keep the IP for days if the modem is not restarted; others change it on every reconnect. Mobile networks usually change it each time you toggle mobile data.
Is a static proxy the same as a static IP from my provider?
It is the same in that the outgoing IP is fixed. It differs in that a proxy only applies to the software you configure and does not accept incoming connections. To host a server at home, you need a static IP from your provider.
How do I get a new dynamic IP?
Restarting the modem, or toggling airplane mode on a phone, is usually enough to get a new IP. If you need an IP in another country, you need a proxy or a VPN; see proxy vs VPN.
Do 4G connections have static IPs?
Regular 4G plans use dynamic IPs and usually go through CGNAT, so many subscribers share one IP. Static IPs on mobile networks are only offered on some business plans.
A static IP in the US or Vietnam, no plan change needed
Static ISP proxies keep one fixed IP for the whole rental, dedicated to you, with username and password authentication.
See static ISP proxies