What Is the Taproot Upgrade?

A simple Bitcoin payment and a complex multi-party agreement can now look completely identical on the blockchain — and that’s exactly the point of Bitcoin’s Taproot upgrade.

Taproot is a Bitcoin protocol upgrade that activated in November 2021, bringing three technical improvements bundled together: Schnorr signatures, a new signature scheme; MAST, a way to organize complex spending conditions; and the Taproot output format itself, which ties these improvements together into how transactions are structured on-chain.

The headline benefit is privacy and efficiency through uniformity. Before Taproot, a transaction with complex spending conditions — say, a multisignature setup requiring several parties to approve a payment — looked visibly different on the blockchain from a simple single-signature payment. Taproot allows complex conditions to look exactly like an ordinary payment on-chain, as long as everyone involved cooperates normally.

Schnorr signatures specifically also enable signature aggregation — combining multiple signatures from a multi-party transaction into a single, smaller signature, which reduces the data size of complex transactions and therefore their fees, compared to the older signature scheme.

MAST lets a transaction with several possible spending conditions reveal only the specific condition actually being used when spent, rather than exposing every possible condition on-chain regardless of which one was actually invoked.

Like SegWit before it, Taproot activated as a backward-compatible soft fork — nodes running older software continued to see Taproot transactions as valid without needing to understand every new feature, avoiding any network split. Adoption has grown steadily since 2021.

Curious how Bitcoin coordinates a protocol change like this across the entire network? Continue learning in the Bitcoin Academy.