Developers Home»docs»SS58 Address Format

SS58 Address Format

SS58 is a simple address format designed for Substrate based chains. There's no problem with using other address formats for a chain, but this serves as a robust default. It is heavily based on Bitcoin's Base-58-check format with a few alterations.

The basic idea is a base-58 encoded value that can identify a specific account on the Substrate chain. Different chains have different means of identifying accounts. SS58 is designed to be extensible for this reason.

Validating addresses

There are several ways to verify that a value is a valid SS58 address.


You can use the Subkey inspect subcommand, which accepts the seed phrase, a hex-encoded private key, or an SS58 address as the input URI. If the input is a valid address, it will return a list containing the corresponding public key (hex), account ID, and SS58 values.

Subkey assumes that an address is based on a public/private keypair. In the case of inspecting an address, it will return the 32 byte account ID. Not all addresses in Substrate-based networks are based on keys.


If you input a valid SS58 value, Subkey will also return a network ID/version value that indicates for which network the address has been encoded.

# A valid address.
$ subkey inspect "12bzRJfh7arnnfPPUZHeJUaE62QLEwhK48QnH9LXeK2m1iZU"
Public Key URI `12bzRJfh7arnnfPPUZHeJUaE62QLEwhK48QnH9LXeK2m1iZU` is account:
  Network ID/version: polkadot
  Public key (hex):   0x46ebddef8cd9bb167dc30878d7113b7e168e6f0646beffd77d69d39bad76b47a
  Account ID:         0x46ebddef8cd9bb167dc30878d7113b7e168e6f0646beffd77d69d39bad76b47a
  SS58 Address:       12bzRJfh7arnnfPPUZHeJUaE62QLEwhK48QnH9LXeK2m1iZU

# An invalid address.
$ subkey inspect "12bzRJfh7arnnfPPUZHeJUaE62QLEwhK48QnH9LXeK2m1iZUInvalidAddress"
Invalid phrase/URI given

PolkadotJS API

For verifying an address in your JavaScript projects, you can utilize the functions built into the PolkadotJS API.

// Import Polkadot.js API dependencies.
const { decodeAddress, encodeAddress } = require('@polkadot/keyring')
const { hexToU8a, isHex } = require('@polkadot/util')

// Specify an address to test.
const address = '<addressToTest>'

// Check address.
const isValidSubstrateAddress = () => {
  try {
    encodeAddress(isHex(address) ? hexToU8a(address) : decodeAddress(address))

    return true
  } catch (error) {
    return false

// Query result.
const isValid = isValidSubstrateAddress()

Community Built

Below you will find a list of other Substrate API tools built in various languages by our community. They each validate addresses in their own way, and can act as a starting point.

Learn more

Last edit: on

Was This Page Helpful?
Help us improve