Bitcoin address checker

Paste a Bitcoin address to check that it's valid and see exactly what it is: its type, network, encoding, checksum, witness program and the output script a payment to it creates. Everything is decoded in your browser, following the rules in BIP 173 and BIP 350.

Updated 2026-10-20 · 5 min read

Free, and runs entirely in your browser: nothing you type is sent anywhere.

How to use the address checker

1. Paste an address into the box, or pick one of the examples (one for every address type, mostly taken from the BIP test vectors).
2. Read the result. A valid address shows its type, network, encoding and checksum, the witness version and program (or the 20-byte hash for older types), the scriptPubKey in hex and as opcodes, and the BIPs that define it.
3. If the address is invalid, the checker says exactly which rule it breaks. For a mistyped bc1 address it also highlights the one or two characters most likely to be wrong.

It also recognises things people paste by mistake: extended public keys (xpub, ypub, zpub), Lightning invoices and offers, silent payment addresses, bitcoin: payment links (open those in the payment link tool) and output scripts in hex. If you paste something secret, such as a seed phrase, a WIF private key or an xprv, it stops, warns you, and keeps it out of the page address.

What type of Bitcoin address is this?

The first characters tell you the type. The checker confirms it by decoding the whole address, because the prefix alone can be faked by a typo.

Test networks use different prefixes for the same types: tb1 for testnet and signet, bcrt1 for regtest, and m, n or 2 for the Base58 types. Coins sent on those networks have no value. The address types guide explains each type in depth.

bc1q vs bc1p: what's the difference?

The character after bc1 is the SegWit version, written in the Bech32 alphabet: q is version 0 and p is version 1. A bc1q address is native SegWit (BIP 141) and uses the Bech32 checksum. A bc1p address is Taproot (BIP 341) and uses Bech32m (BIP 350).

Both are cheap to spend. Taproot adds privacy: a key-path spend looks the same whether one key, a MuSig2 multisig or a hidden script tree controls the coins. Its output is 12 bytes larger than P2WPKH, but its typical input is smaller. Any wallet that supports BIP 350 can send to both; wallets that only implement BIP 173 can't send to bc1p. The BIP 173 vs BIP 350 comparison covers the details.

How address checksums catch typos

Base58Check (addresses starting with 1 or 3) adds 4 bytes to the version byte and 20-byte hash: the start of SHA-256 applied twice. A typo almost always breaks it, but the checksum can't say where the mistake is.

Bech32, designed by Pieter Wuille and Greg Maxwell in BIP 173, uses a BCH code instead. It guarantees to detect any error affecting up to 4 characters, with less than a 1 in a billion chance of missing more. It can also locate a few substituted characters, which is how this checker highlights them. BIP 173 says software should only point at likely errors, never "correct" an address, so the tool doesn't suggest a fix.

Bech32m (BIP 350, by Pieter Wuille) changes one constant in the checksum. Bech32 has a weakness: when the last character is a p, inserting or deleting q characters just before it doesn't break the checksum. Version 0 addresses have fixed lengths, so they're safe, but newer versions aren't. Since BIP 350, version 0 must use Bech32 and versions 1 to 16 must use Bech32m. A Taproot address with an old Bech32 checksum is rejected, so outdated software can't burn coins by mangling it.

Every rule the checker applies

• Base58 addresses: only Base58 characters (no 0, O, I or l), a valid double SHA-256 checksum, 21 bytes of payload, and a version byte of 0x00 or 0x05 (mainnet) or 0x6f or 0xc4 (test networks).
• Bech32 and Bech32m addresses: at most 90 characters, all lowercase or all uppercase (never mixed), prefix bc, tb or bcrt, and a valid checksum.
• A SegWit version from 0 to 16, and a witness program of 2 to 40 bytes with at most 4 bits of zero padding.
• Version 0 programs are exactly 20 bytes (P2WPKH) or 32 bytes (P2WSH), and version 0 uses Bech32 while later versions use Bech32m.

These are the rules and test vectors from BIP 173 and BIP 350; the checker passes all of them.

What a valid address doesn't tell you

A valid checksum proves the address wasn't mistyped, not that it belongs to the person you mean to pay. Malware that swaps copied addresses produces perfectly valid ones, so compare the address on your hardware wallet's screen or with the recipient. The checker works offline, so it can't show balances or history.

Some valid addresses shouldn't receive payments. Versions 2 to 16, and version 1 programs other than Taproot's 32 bytes, have no spending rules yet, so anyone could take coins sent there today. A P2A output is spendable by anyone by design. And for privacy, use a fresh address for every payment: reusing one links your payments together on-chain.