An IP address is either 32 bits long (IPv4) or 128 bits long (IPv6), which translates to either 4 numbers or 8 groups of numbers separated by colons

When people ask how long an IP address is, they usually mean one of two things: how many characters you see on screen, or how much data the address actually contains. The answer depends on which version of IP you're using.

An IPv4 address — the kind you've probably seen — looks like 192.168.1.1. That's 4 numbers (called octets) separated by dots. Each number ranges from 0 to 255. On screen, an IPv4 address is typically 7 to 15 characters long, depending on whether the numbers are single digits or three digits.

An IPv6 address — the newer standard — looks like 2001:0db8:85a3:0000:0000:8a2e:0370:7334. That's 8 groups of numbers (in hexadecimal, meaning they use letters A through F as well as 0 through 9) separated by colons. On screen, a full IPv6 address is typically 39 characters long, though it can be shortened using compression rules.

Key Takeaways

  • IPv4 addresses contain 32 bits of data and display as four numbers separated by dots, like 192.168.1.1.
  • IPv6 addresses contain 128 bits of data and display as eight groups of hexadecimal numbers separated by colons, like 2001:0db8:85a3::8a2e:0370:7334.
  • The difference in length reflects how many unique addresses each system can create — IPv4 allows about 4.3 billion addresses, while IPv6 allows vastly more.
  • You don't need to memorize or type out your IP address in most situations; your device handles it automatically.

Why IPv4 addresses are only 32 bits

IPv4 was designed in the 1980s when the internet was much smaller. The designers chose 32 bits as a balance between having enough unique addresses and keeping the system simple to implement. With 32 bits, you can create about 4.3 billion unique addresses — which seemed like plenty at the time.

Each of the four numbers in an IPv4 address represents 8 bits. Since 8 bits can represent values from 0 to 255, that's why each number in an IPv4 address is always between 0 and 255. The four numbers together give you 32 bits total.

The problem is that 4.3 billion addresses turned out not to be enough. As more devices connected to the internet, addresses ran out. That's one of the main reasons IPv6 was created.

Why IPv6 addresses are 128 bits

IPv6 uses 128 bits instead of 32, which creates vastly more possible addresses. The exact number is 340 undecillion — a number so large it's difficult to put into perspective, but it's enough that every device on Earth could have multiple unique addresses for centuries.

The 128 bits are divided into 8 groups of 16 bits each. Each group is written in hexadecimal (base 16) rather than decimal (base 10), which is why you see letters mixed in with numbers. Hexadecimal is more compact — it can represent larger values with fewer characters than decimal would.

IPv6 addresses can also be compressed. If a group contains all zeros, you can replace it with a double colon (::), but only once per address. So 2001:0db8:85a3:0000:0000:8a2e:0370:7334 can be shortened to 2001:0db8:85a3::8a2e:0370:7334. This compression makes IPv6 addresses easier to write and read, even though they're longer in their full form.

How the length affects what you can do with an IP address

The length of an IP address doesn't change how you use it in daily life. Whether you're visiting a website, sending an email, or connecting to a printer, your device handles the IP address automatically. You rarely need to type one in or remember it.

The length does matter for network administrators and people setting up home networks. A longer address (IPv6) means more flexibility in how networks are organized and more room for growth. It also means that devices can be assigned addresses more efficiently, without the workarounds that IPv4 networks sometimes need.

For security purposes, the length of an IP address doesn't make it more or less secure. What matters is how the address is protected and what information is logged about where it goes. A longer address doesn't hide your location or activity any better than a shorter one.

When you'll see IPv4 versus IPv6

Most of the internet still runs on IPv4, even though IPv6 has been available since 1998. Your home router probably assigns IPv4 addresses to your devices. When you look up your IP address online, you're usually seeing an IPv4 address.

IPv6 is growing, especially in certain regions and on newer networks. Some internet service providers now assign IPv6 addresses alongside IPv4. Major websites and services like Google, Facebook, and Netflix support IPv6, but many smaller sites still don't.

You might have both an IPv4 and an IPv6 address at the same time. Your device can use whichever one the network or service requires. This dual-stack approach is how the internet is gradually transitioning from IPv4 to IPv6.

How IP address length relates to network masks

When you set up a network, you also use something called a subnet mask or CIDR notation, which tells your device which part of the IP address identifies the network and which part identifies the specific device.

In IPv4, a subnet mask looks like 255.255.255.0 — another set of four numbers. In CIDR notation, you'd write it as /24, meaning the first 24 bits identify the network and the remaining 8 bits identify the device. The length of the address itself doesn't change, but the mask determines how the bits are divided.

IPv6 uses the same CIDR concept. A typical IPv6 network might be written as 2001:0db8:85a3::/48, meaning the first 48 bits identify the network. Again, the full address is still 128 bits; the notation just tells you how those bits are split.

Frequently Asked Questions

Can I shorten an IPv4 address the way you can shorten IPv6?

No. IPv4 addresses don't have a standard compression method like IPv6's double-colon notation. You always write out all four numbers. However, in some technical contexts, leading zeros are dropped (so 192.001.001.001 becomes 192.1.1.1), but that's just removing unnecessary zeros, not true compression.

Does a longer IP address mean slower internet?

No. The length of the address itself doesn't affect your internet speed. IPv6 addresses are longer, but they don't make your connection slower or faster. What matters for speed is your connection type (fiber, cable, DSL) and network congestion, not the address format.

Why do some IP addresses have letters in them?

Those are IPv6 addresses using hexadecimal notation. Hexadecimal uses digits 0-9 and letters A-F to represent values 0-15 in each position. It's more compact than decimal, so it lets you represent more information in fewer characters. IPv4 addresses only use decimal (0-9), so they never have letters.

If I know someone's IP address, can I find out exactly where they are?

An IP address tells you the general location — usually the city or region where the internet service provider is based — but not the exact street address or building. The precision varies depending on the database used. A VPN or proxy will show a different location entirely, masking the real one.

Will my IP address change if I restart my router?

Usually yes, but not always. If your internet service provider assigns addresses dynamically (which most do), restarting your router will often get you a new address. If you have a static address (less common for home users), it will stay the same. You can ask your provider which type you have.