Bitcoin Address Length

A Bitcoin address, or simply address, is an identifier of 27-34 alphanumeric characters, beginning with the number 1 or 3, that represents a possible destination for a Bitcoin payment. Addresses can be generated at no cost by any user of Bitcoin. For example, using Bitcoin-Qt, one can click "New Address" and be assigned an address. It is also possible to get a Bitcoin address using an account at an exchange or online wallet service.

An example of a Bitcoin address is 3J98t1WpEZ73CNmQviecrnyiWrnqRhWNLy.

A Bitcoin address is like an e-mail address

Like e-mail, you can send bitcoins to a person by sending bitcoins to one of their addresses. A person can have many different Bitcoin addresses and, for increased privacy and as the only way to know what the bitcoins are received for/from, it is recommended that you use a unique address for each transaction. Most Bitcoin software and websites will help with this by generating a brand new address each time you perform a transaction. Some services provide a facility to request a new Bitcoin address for use with their service when desired.

When using a web site that accepts bitcoins or holds Bitcoin balances on your behalf, that website will assign a Bitcoin address to your account, so you can transfer funds into your account at the site. Very much unlike e-mail, this address may change every time funds come in so care should be taken when sending additional funds to a previously-used address. When you send Bitcoins to your account at a web site, they will usually be credited to your account at that web site after the transaction is confirmed.

Addresses can be created offline

Creating addresses can be done without an Internet connection and does not require any contact or registration with the Bitcoin network. The network starts tracking an address when it is first seen in a valid payment transaction.