Monad mainnet upgrade reduces data storage costs by 98%

The EVM-compatible blockchain Monad activated its MonadTen revision, featuring the MIP-8 upgrade, on its mainnet on September 2, 2026. The upgrade replaces slot-by-slot warming with 128-slot, 4KB storage pages for gas accounting. This reduces clustered data storage costs by 98%, dropping subsequent reads on a warmed page from 8,100 to 100 gas. While Solidity layouts can inherit this discount automatically, developer tooling must adapt to the new page-based access model.

MIP-8 mainnet activation

• ▪The official MonadTen release record set the activation of the MIP-8 upgrade at Unix timestamp 1788359400, prior to which MonadNine rules remained in force.
• ▪A block-pinned mainnet call on Monad mainnet block 101672712 reproduced the gas step-down from 8,100 to 100 gas, showing the cold charge returning at slot 128.
• ▪The EVM-compatible blockchain Monad activated its MonadTen revision, featuring the MIP-8 upgrade, on its mainnet at 14:30 UTC on September 2, 2026.

Page-based storage gas model

• ▪The MIP-8 upgrade replaces slot-by-slot warming with 128-slot, 4KB storage pages for gas accounting, where each page consists of 128 words of 32 bytes each.
• ▪Under Monad's prior schedule, reading two adjacent, previously untouched storage slots cost 8,100 gas each, whereas under the MIP-8 upgrade they cost 8,100 gas and 100 gas if they fall within one page.
• ▪Under the MIP-8 specification, the first storage read (SLOAD) on a 4KB page costs 8,100 gas, while subsequent reads within that same warmed page cost 100 gas.

Storage layout optimization incentives

• ▪Sequential state variables, struct fields, and array elements in common Solidity layouts inherit the MIP-8 discount automatically because they occupy consecutive slots.
• ▪While mapping keys generally resolve to dispersed pages, fields inside a struct stored under a mapping key remain contiguous and can share the MIP-8 page-level discount.
• ▪Under the MIP-8 upgrade, hashed or unaligned storage reads that cross page boundaries do not receive a discount and continue to cost the baseline of 8,100 gas each.

Developer tooling compatibility impact

• ▪The MIP-8 specification identifies smart contracts that hardcode storage-opcode gas costs as the primary compatibility-risk class.
• ▪Under the MIP-8 upgrade, EIP-2930 entries warm storage pages, and proof formats must represent the page model.
• ▪The MIP-8 upgrade preserves EVM execution semantics but changes assumptions for developer tooling that builds access lists, storage proofs, or gas estimates.

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