What it is
Segregated Witness, commonly known as SegWit, is a soft fork upgrade implemented on the Bitcoin network in 2017. Its primary function is to "segregate" or separate the transaction signature data (witness data) from the main transaction data. By moving witness data to a separate structure, SegWit effectively reduces the size of transactions within a block, allowing more transactions to fit into each 1MB block without changing the block size limit itself.
SegWit's implementation was a significant event in Bitcoin's history, often discussed in relation to scalability debates and transaction fees. News reports frequently mention SegWit when discussing network efficiency, transaction throughput, or the adoption of newer Bitcoin features. Readers need to understand that SegWit made blocks more efficient, paving the way for further innovations like the Lightning Network and reducing average transaction costs for users who adopt it.
Why it matters
SegWit improves Bitcoin's transaction capacity and efficiency, potentially lowering fees and speeding up confirmations for your transactions. It underpins many network improvements.
Reviewed under editorial standardsUpdated September 26, 2026Not investment advice