Bech32 Addresses

Cosmos uses Bech32 encoding for all addresses. A Bech32 address has two parts: a human-readable prefix (HRP) that identifies the chain, and a data section containing the raw address bytes with a checksum.

cosmos1qypqxpq9qcrsszg2pvxq6rs0zqg3yyc5lzv7xu
 ^                    ^
 |                    +-- data + checksum (base32 encoded)
 +-- prefix (HRP)

Common Prefixes

Chain	Address prefix	Validator prefix
Cosmos Hub	`cosmos`	`cosmosvaloper`
Osmosis	`osmo`	`osmovaloper`
Juno	`juno`	`junovaloper`
Neutron	`neutron`	`neutronvaloper`
CosmWasm testnet	`wasm`	`wasmvaloper`

Encoding and Decoding

@cosmjs/encoding provides three functions:

import { toBech32, fromBech32, normalizeBech32 } from "@cosmjs/encoding";

const address = toBech32("cosmos", rawAddressBytes);
// "cosmos1..."

const { prefix, data } = fromBech32("cosmos1qypq...");
// prefix: "cosmos", data: Uint8Array (20 bytes)

const normalized = normalizeBech32("COSMOS1QYPQ...");
// "cosmos1qypq..." (lowercased and validated)

fromBech32 validates the checksum and throws on invalid input. normalizeBech32 round-trips through decode/encode, which is safer than calling toLowerCase() directly.

How Addresses Are Derived from Public Keys

The raw 20-byte address inside a Bech32 string is derived from the public key through hashing. The algorithm depends on the key type:

Key type	Derivation
secp256k1	`ripemd160(sha256(compressedPubkey))`
ed25519	`sha256(pubkey).slice(0, 20)`
eth_secp256k1	`keccak256(uncompressedPubkey[1:]).slice(-20)`
multisig	`sha256(aminoEncodedPubkey).slice(0, 20)`

The @cosmjs/amino package provides pubkeyToAddress for this:

import { pubkeyToAddress } from "@cosmjs/amino";

const address = pubkeyToAddress(pubkey, "cosmos");

This means the same key pair produces different addresses on different chains — only the Bech32 prefix changes, but the raw bytes are identical:

const cosmosAddr = toBech32("cosmos", rawAddress); // cosmos1abc...
const osmoAddr = toBech32("osmo", rawAddress);     // osmo1abc...

CosmJS

Concepts

Guides

API Reference

Common Prefixes

Encoding and Decoding

How Addresses Are Derived from Public Keys

​Common Prefixes

​Encoding and Decoding

​How Addresses Are Derived from Public Keys

Common Prefixes

Encoding and Decoding

How Addresses Are Derived from Public Keys