> For the complete documentation index, see [llms.txt](https://help.tokenpocket.pro/en/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.tokenpocket.pro/en/wallet-faq-en/btc-wallet/segwit.md).

# What's the SegWit

Segregated Witness (abbreviated as SegWit) is an implemented protocol upgrade intended to provide protection from transaction malleability and increase block capacity. SegWit separates the *witness* from the list of inputs. The witness contains data required to check transaction validity but is not required to determine transaction effects.

Additionally, a new *weight* parameter is defined, and blocks are allowed to have at most 4 million weight units (WU). Non-witness and pre-segwit witness bytes weigh 4 WU, but each byte of Segwit witness data only weighs 1 WU, allowing blocks that are larger than 1 MB without a hard forking change.