Polygon PoS is set to activate the Heimdall v2 consensus layer upgrade on July 10, marking its most technically advanced hard fork since the network’s 2020 launch.

The upgrade reduces finality to approximately 5 seconds and eliminates legacy technical debt in full.

Polygon’s proof-of-stake (PoS) network is rolling out a major consensus-layer overhaul with the Heimdall v1 → v2 migration, scheduled for mainnet on July 10, 2025. Heimdall is the consensus client that manages validators, checkpointing to Ethereum, and state synchronization between Ethereum and Polygon PoS, so changes at this layer directly affect finality, bridging, and overall network reliability. The upgrade replaces the legacy Tendermint-based Heimdall with a new CometBFT + Cosmos SDK–based client, introduced as the network’s most technically advanced hard fork since its 2020 launch. Functionally, Heimdall v2 is designed to deliver a significant performance jump: finality is expected to fall from ~90 seconds to roughly 4–6 seconds, and Bor block times on Polygon PoS are targeted to shrink from around 5–6 seconds to about 2 seconds. Polygon positions this as enabling “~5 second fast finality,” allowing payments, stablecoin transfers, and tokenized assets to settle at speeds closer to mainstream payment systems. The upgrade also clears accumulated “technical debt” from the original 2018–2019-era design, modernizing validator management, state sync, and checkpoint processes and aiming for better stability and future-proofing of the core infrastructure. Operationally, the migration introduces a new chain ID for Heimdall, with Heimdall v2 starting from a new genesis block derived from the final state of Heimdall v1, while preserving application data such as balances, accounts, checkpoints, and state syncs—but not the full Heimdall chain history. Bor, the Polygon PoS execution layer, is expected to continue producing blocks during the migration, meaning the chain itself should avoid downtime, though checkpoint submissions, deposits, withdrawals, and canonical bridging via Polygon Portal will be temporarily paused during the upgrade window. Polygon has advised validators and infrastructure operators to prepare for new APIs, updated key handling, and higher hardware requirements, and it has cautioned dapps and bridges to briefly raise confirmation thresholds due to possible short-lived reorg risk around the migration. This consensus overhaul builds on the earlier Bhilai hard fork, which pushed Polygon PoS toward 1,000+ TPS, and is framed as a foundational step to support high-throughput payments and real-world asset use cases on the network.

✨ AI-generated background, compiled from web sources — not editorial content.

More coverage

• Polygon Hits ~5 Second Fast Finality in Significant Upgrade (polygon.technology)
• Polygon surges 10% ahead of Heimdall v2 upgrade - CryptoSlate (cryptoslate.com)
• Polygon Drops Urgent Alert as Major POL Upgrade Launches (binance.com)
• Polygon Heimdall V2 Launches with Big Upgrades - Altcoin Buzz (altcoinbuzz.io)
• The most complex upgrade in Polygon history is live! Heimdall v2 ... (x.com)

Explore the topic

• fork
• Launch