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Taproot Activation

5 min read

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Taproot was Bitcoin's largest soft fork since SegWit and, like CSV (BIPs 68/112/113) and SegWit (BIPs 141/143/147) before it, bundled several BIPs into a single activation. Schnorr signatures (BIP 340), Taproot output spending (BIP 341), and Tapscript (BIP 342) all activated together at block 709,632 on November 14, 2021. Together they reshape how multisig, smart contracts, and key aggregation work on Bitcoin.

The activation itself was almost boring, miner signaling cleared the 90% threshold six weeks after Speedy Trial started and the lock-in period finished at 98%. The technical surface area, on the other hand, is enormous. Years of research went into producing it.

Speedy Trial

Bitcoin's previous soft-fork activations (CSV, SegWit) used BIP9 versionbits with multi-month signaling windows that miners could deadlock by withholding signal. Taproot used a new mechanism, Speedy Trial (a modified BIP9 with a 90% threshold and a fixed minimum activation height), that gives miners a defined three-month window to signal and either locks in at the threshold or fails the trial.

Speedy Trial signaling started at block 681,408 on May 1, 2021 (the start time was April 24, but signaling periods begin on retarget boundaries). Lock-in happened at 687,456 in June 2021. Activation was fixed in advance at block 709,632 (the minimum activation height), which came five months after lock-in.

Open in playground → first locked-in block, June 13 2021 (90% reached on June 12)
Open in playground → activation block, November 14 2021
Open in playground → check timestamp + version field

What changed

Three things shipped together:

Why key aggregation matters

Pre-Taproot, a 2-of-3 multisig wallet put two signatures and three pubkeys on chain. Anyone watching could see "this is multisig" and how many parties were involved.

Post-Taproot with Schnorr key aggregation (MuSig2 for n-of-n, FROST for true thresholds like 2-of-3), the cooperative spend can produce a single aggregated key and a single signature. On chain, it's indistinguishable from a single-sig spend. The privacy gain for high-value custody arrangements is enormous.

There's a subtle script-path side: if the parties can't reach agreement off chain, the alternative-path Merkle tree can include the explicit "any 2 of these 3 keys" script. That fallback is only revealed if used; in the happy path, nobody outside the wallet knows the multisig structure exists.

Adoption since

Taproot adoption was initially slow, most wallets defaulted to bech32 SegWit addresses (bc1q...) for years. Sparrow offered bc1p as an opt-in script type from activation day, November 14, 2021, but kept Native SegWit (bc1q) as its default. Inscriptions (Bitcoin Ordinals) emerged in early 2023 as a use of the Tapscript script-path, not the spending path Taproot's authors had in mind. Inscriptions accelerated bc1p adoption, even if controversially.

Pull a block from September 2026 and check its height and transaction count:

Open in playground → current tip
Open in playground → block stats, September 28 2026

Want to look at a specific Taproot-spending tx? Search a block at verbose=2 and find outputs with type witness_v1_taproot. Their addresses are bech32m-encoded starting with bc1p.

The political backstory

Unlike SegWit, Taproot's activation was relatively quiet. The technical community had been working on the design since 2018: Gregory Maxwell proposed Taproot on the bitcoin-dev list in January 2018, and Pieter Wuille, Jonas Nick, and Anthony Towns published the BIP drafts in May 2019. Speedy Trial was a deliberate choice to end an activation-method debate that had already run for more than a year.

Miner signaling missed the 90% threshold in the first two signaling periods and crossed it in the third, on June 12, 2021, six weeks after signaling began. Activation was, by Bitcoin standards, drama-free. The drama came later, when Ordinals turned out to use Tapscript in ways the proponents of Taproot hadn't anticipated. That story gets its own page.

Sources

Read more: The Halvings.