IPv4 addresses are 32 bits long, meaning each IPv4 address consists of 32 binary digits. This allows for a total of about 4.29 billion unique IPv4 addresses

. IPv6 addresses are much longer, consisting of 128 bits. This expansion was made to accommodate the vast growth of internet-connected devices. The 128-bit length allows for approximately 3.4×10383.4\times 10^{38}3.4×1038 unique IPv6 addresses, which is vastly larger than IPv4's address space

. In summary:

• IPv4 addresses: 32 bits long
• IPv6 addresses: 128 bits long