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IP Class Identifier
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IP Class Identifier

Classify any IP — public, private, loopback, link-local, multicast, or reserved — for both IPv4 classes and IPv6 special ranges.

Works Offline100% Free

Processed 100% locally in your browserPrivate & Safe

IP Class Identifier runs entirely on your device using Web API standards. No data is ever uploaded to UtilixVerse servers.

Your Input
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Browser
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Result
No Server UploadsNo Account RequiredWorks OfflineZero Data Logging

IP Address

8.8.8.8IPv4
Legacy Class
Class A
Default Mask
255.0.0.0 (/8)
First Octet (binary)
00001000

Per classful addressing: 126 networks × 16,777,214 hosts each.

Address Type
Public — globally routable

IPv4 Class Reference

ClassRangeDefault MaskNetworksHostsUse
Class A0.0.0.0 – 127.255.255.255255.0.0.012616,777,214Very large networks
Class B128.0.0.0 – 191.255.255.255255.255.0.016,38465,534Medium networks
Class C192.0.0.0 – 223.255.255.255255.255.255.02,097,152254Small networks
Class D224.0.0.0 – 239.255.255.255———Multicast
Class E240.0.0.0 – 255.255.255.255———Reserved

Free IP Class Identifier — Identify IP Class & Address Type

Welcome to the UtilixVerse IP Class Identifier — a free, browser-based tool that identifies the class and type of any IP address in seconds. Enter an IPv4 or IPv6 address and the tool instantly reports its legacy class (A–E), default subnet mask, class statistics, and its special-purpose type — public, private (RFC 1918), loopback, link-local, multicast, CGNAT, documentation, or reserved. Everything runs 100% in your browser — free, private, and offline.

How the IP Class Identifier Works

IPv4 addresses are classified two ways. The legacy classful system (RFC 791) reads the first octet: 1–126 = Class A, 128–191 = Class B, 192–223 = Class C, 224–239 = Class D (multicast), 240+ = Class E (reserved). The special-purpose system (RFC 6890) checks reserved ranges such as10.0.0.0/8, 127.0.0.0/8 and 192.168.0.0/16. IPv6 addresses are typed by their leading bits (2000::/3 global,fe80::/10 link-local, fc00::/7 unique local, ff00::/8 multicast, ::1 loopback).

Quick Reference: IPv4 Classes

Class A 0.0.0.0–127.255.255.255 (mask 255.0.0.0) — 126 networks with 16.7M hosts each. Class B 128.0.0.0–191.255.255.255 (mask 255.255.0.0) — 16,384 networks with 65,534 hosts. Class C 192.0.0.0–223.255.255.255 (mask 255.255.255.0) — 2M networks with 254 hosts. Class D 224.0.0.0/4 multicast. Class E 240.0.0.0/4 reserved.

Who Uses This Tool

Networking students studying for CCNA/Network+ exams,IT professionals auditing address usage, security analysts spotting reserved or non-routable addresses in logs, and developers validating user input all need fast, reliable IP classification. No install, no sign-up, and nothing leaves your device.

Frequently Asked Questions About IP Classes

What are IP address classes?

The original IPv4 addressing scheme (RFC 791, 1981) split addresses into five classes based on the leading bits. Class A (0-127) for enormous networks, Class B (128-191) for medium ones, Class C (192-223) for small ones, Class D (224-239) reserved for multicast, and Class E (240-255) reserved for experiments. Each class had a fixed default subnet mask and a fixed split between network and host bits — a design that was replaced by classless CIDR in 1993.

Why is 192.168.1.10 a private address?

RFC 1918 reserved three ranges that anyone may use inside a private network: 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16. Because 192.168.1.10 falls inside 192.168.0.0/16, it is a private address — it is valid on a LAN but never routed on the public internet. Routers NAT it to a public address when traffic needs to leave the network.

What is the difference between public, private, loopback, and multicast IPs?

Public addresses are globally routable and unique on the internet. Private addresses (RFC 1918) are reusable inside LANs. Loopback addresses (127.0.0.0/8, especially 127.0.0.1) let a device talk to itself. Link-local (169.254.0.0/16) is self-assigned when a device cannot reach DHCP. Multicast (224.0.0.0/4) sends to a group of receivers. This tool flags all of these automatically, plus documentation, CGNAT, and reserved ranges.

Is classful addressing still used today?

Not for routing — since 1993 the internet has used classless inter-domain routing (CIDR), which allows any prefix length from /0 to /32, so address space is used far more efficiently. The classes remain useful as a historical and educational concept, appear in many networking exam syllabuses, and this tool still reports the legacy class of an address for reference.

What is a /8, /16, or /24 network?

These are the CIDR prefixes that replaced the fixed class masks. A /8 has a 255.0.0.0 mask and 16.7 million addresses (this is what Class A originally meant). A /16 has 255.255.0.0 and 65,536 addresses (originally Class B). A /24 has 255.255.255.0 and 256 addresses (originally Class C). Modern networks pick any prefix, not just these three.

How is an IPv6 address classified?

IPv6 uses the leading bits of the first hextet to mark the address type: 2000::/3 is global unicast (the public internet), fe80::/10 is link-local (auto-configured on each interface), fc00::/7 is unique local (like private addresses), ff00::/8 is multicast, ::1 is loopback, and :: is unspecified. This tool recognizes all of these and labels them automatically.

Is this IP class identifier free and private?

Yes — completely free, no registration, and 100% private. Classification runs locally in your browser; the IP address you enter is never sent to any server. The tool works offline after the page loads.

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