- Heimdall v2 cuts finality to 5 seconds, boosting speed and user experience.
- The upgrade removes legacy code, modernizing Polygon’s PoS consensus layer.
- Faster finality and better reliability may drive more DeFi and institutional use.
Polygon is set to implement the Heimdall v2 upgrade on July 10, 2025. This migration is expected to be the most technically complex since the Polygon PoS chain launched in 2020. The primary objective of Heimdall v2 is to eliminate outdated architecture and reduce finality time to approximately five seconds.
The upgrade reflects a major shift from the legacy Tendermint and Cosmos SDK v0.37 stack to a modernized architecture. Heimdall v2 incorporates a fork of CometBFT and upgrades to Cosmos SDK v0.50.x. This upgrade is expected to optimize network operations, improve performance, and enable future protocol innovations.
Technical Overhaul and Modernization of Heimdall
Heimdall v2 discards technical debt that originated from its 2018–2019 development phase. It transitions from using Tendermint to a CometBFT-based engine, reflecting a more scalable and resilient infrastructure. The upgrade also integrates custom modules for staking, checkpoints, and governance into a more modular framework.
New APIs and module structures introduced in Heimdall v2 require developers and node operators to adapt existing codebases. This includes updating endpoints and adjusting for changes in the authentication, banking, and governance modules, now handled via the updated Cosmos SDK. This move supports more efficient processing and system-level enhancements, aligning the network with industry standards.
The expected time for automated migration on the mainnet is approximately 30 minutes. Manual and containerized migration options are also available, supported by official scripts and documentation. During migration, Heimdall will temporarily pause, though the Bor chain will remain active, preventing a full network outage.
Enhancing Finality, User Experience, and Developer Agility
One of the core improvements of Heimdall v2 is the significant reduction in transaction finality time. Finality is expected to decrease to around five seconds, which minimizes the potential for reorganization beyond two blocks. This directly enhances the user experience by accelerating transaction confirmation and improving overall throughput.
Faster finality is particularly crucial for decentralized applications (dApps) that rely on timely settlement and consistent state updates. It also enhances the security of bridging operations, which rely on accurate checkpointing between different blockchains. The increased speed and reliability make the platform more attractive for developers building performance-sensitive applications.
During the migration window on July 10, finality may be delayed by approximately three hours. Developers and dApp teams are advised to increase block confirmation thresholds to 256 blocks temporarily. This precaution ensures stability during potential network reorganizations, although such events are unlikely to occur.
Empowering the Place of the Polygon in the Layer 2 Landscape
The upgrade will help Polygon to strengthen its position in the high-performing blockchain Layer 2 industry. The increased speed of finality and modernization of the infrastructure are an extension of existing initiatives to attract institutional investors or DeFi solutions willing to deploy their solutions on a scalable, low-latency network.
Heimdall v2 can improve interoperability and resilience over time twofold, strengthening the dependability of checkpoint submissions and cross-chain activities. The upgrade also provides room to add more complex consensus capabilities in the future, thus making Polygon competitive even in that dynamic blockchain world.
Better metrics of performance, such as block times, which are approximately 2 seconds shorter, contribute to a smoother transaction. This benchmark plays a crucial role in applications that process high transaction volumes, such as trading platforms, NFT marketplaces, and payment systems.
Heimdall v2 introduces a new chain ID and begins from the last block committed on the current Heimdall chain. Although the blockchain history will not be migrated, application data such as checkpoints, account balances, and milestone states will carry over. Node operators are advised to retain a v1 RPC node if historical data access is needed.
Related: Ethereum Pectra Upgrade Adds Smart Accounts, Boosts L2 Speed
Migration Preparedness and Ecosystem Coordination
Most validators have already upgraded in preparation for the hard fork. Polygon Foundation CEO Sandeep Nailwal has encouraged node operators to begin testing early and ensure system readiness. Operators must allocate at least 20 GB of RAM and double the size of the Heimdall home directory in disk space to ensure a smooth migration.
The upgrade has been structured to minimize disruption. Bor will continue processing transactions, allowing dApps and users to maintain functionality outside of cross-chain operations. Checkpoints, deposits, and withdrawals will be paused only for the duration of the Heimdall migration process.
Migration runbooks and upgrade instructions are just a couple of examples of key documentation, which is publicly available via the Heimdall v2 GitHub repository. The application developers and stakeholders are advised to receive the latest updates and release tags to ensure compatibility with the updated system.
Polygon removes the technical barriers that have hindered its growth in the industry so far, thereby setting it up with a firm stepping-stone to future scalability with Heimdall v2. The efficiency and architectural upgrade that comes with it could help build institutional trust, engaging in it, which in turn could lead to even greater uptake in both DeFi and enterprise.
