P2WPKH (Pay to Witness Public Key Hash)

P2WPKH - "Pay to Witness Public Key Hash" - is the native SegWit version of P2PKH. It's the single-signature address format that became standard after SegWit activated in 2017. Addresses start with bc1q (e.g. bc1qar0srrr7xfkvy5l643lydnw9re59gtzzwf5mdq).

Functionally identical to P2PKH: lock to a 20-byte public-key hash, unlock with a public key + signature. What changes is where the signature lives.

In SegWit, the unlocking data (the "witness") is separated from the main transaction body. This has two practical consequences:

• Smaller effective fee. Witness data counts at 1/4 the weight of non-witness data. A typical P2WPKH spend costs ~40% less in fees than the equivalent P2PKH spend.
• No transaction malleability. The txid is computed over the non-witness part only. The signature can't be tweaked after broadcast to change the txid. This is what made Lightning practically deployable.

P2WPKH has been Bitcoin Core's default address type since version 0.20.0 (2020), and since 2022 it has been the most common output type on chain in most months. In September 2026 it made up about 53% of new outputs, against about 5% for P2TR (Taproot, bc1p...). For single-key use, Taproot's smaller inputs and bigger outputs leave fees about even with P2WPKH. P2WPKH remains fully supported, cheaper than P2PKH/P2SH, and a perfectly good choice for everyday use.

Like P2PKH, P2WPKH provides defense-in-depth against post-quantum threats: the public key is hashed in the address and only revealed at spend time. Reusing the address loses that cover, because the first spend puts the raw public key in the witness and every later deposit to the address inherits that exposure.