Immutable plans to rebuild the underlying architecture of Immutable Chain using the OP Stack in 2027, converting the gaming network into an 
Ethereum market price and chart rollup while retaining its current blockchain state and chain identifier. The proposed change will cut its block interval from two seconds to one second, but will also introduce a longer native withdrawal period and some additional transaction costs.
Immutable’s November 6 technical announcement, published by chief technology officer Alex Connolly and head of blockchain Ermyas Abebe, targets the middle of 2027 for the migration. The developers say existing accounts, balances, smart contracts and approvals are expected to carry over unchanged, and most users and game developers will not need to take action.
Immutable moves toward an Ethereum rollup model
The current Immutable Chain uses a customized Geth implementation and a bridge based on cross-chain messaging infrastructure from Axelar. Under the planned architecture, transaction data availability and state commitments will move to Ethereum, with withdrawal verification based on proofs instead of the current bridge model. Immutable says it will begin with permissioned fault proofs before moving toward zero-knowledge validity proofs.
The developers describe the upgrade as a way to benefit more directly from the OP Stack’s standard development process, including future Ethereum Virtual Machine improvements and security patches. It is a planned infrastructure change rather than the launch of a new token or the creation of a replacement chain.
Faster blocks come with different withdrawal mechanics
Immutable says block times should fall from two seconds to one second after the migration. That is a measure of block production frequency, not a promise that every game interaction or wallet transfer will complete twice as fast under real-world conditions. Network capacity, transaction costs and application performance still depend on additional factors.
The company also cautioned that transaction fees will rise slightly. More substantially, native withdrawals from the rollup to Ethereum may take about seven days under the proof-based architecture. Faster third-party liquidity bridges may continue to serve users, but their convenience should not be confused with the settlement characteristics of the underlying rollup bridge.
For developers, the shift may affect infrastructure integrations and withdrawal assumptions even if smart contracts remain deployed at their existing addresses. Immutable says it will provide further documentation and advance notice before the migration window.
Existing games and testnet users face different timelines
Immutable reports that its network has handled almost 250 million transactions and been used by more than 18 million wallets, including over six million Immutable Passport users. These are company-reported historical metrics, not independently verified counts of monthly active players.
The company plans to deprecate its existing public testnet for game usage by the end of 2026. It said teams increasingly conduct testing against local environments or the production network, while OP Stack tooling will provide new upgrade-testing options. Developers who still rely on the current testnet should examine the migration documentation rather than assume that environment will remain available.
Immutable expects a temporary interruption in block production lasting several hours when the change occurs. No exact migration date has been announced. The practical test for the plan will be whether wallets, contracts, integrations and bridges continue functioning as described after the network transitions, without unexpected user-facing interruptions.
