Arbitrum activates Elara upgrade, quadrupling Stylus limits to 96 KB

Arbitrum activated ArbOS 61 Elara on August 20, quadrupling Stylus limits to 96 KB and adding optional compliance filters for Orbit chains.

According to Arbitrum's technical documentation, the compliance-filtering tools are disabled by default on Arbitrum One and Nova. Chain owners must explicitly configure each component, selecting an external compliance provider such as TRM Labs or Chainalysis to produce restricted-address lists.

The Stylus contract code size limit jumped from 24 KB to 96 KB on Arbitrum One, a fourfold expansion. The upgrade also introduces customizable priority fees for Orbit chain operators, ships an alternative data-availability interface for dedicated chains, and modifies base-fee administration through a new BaseFeeManager contract.

The upgrade positions Arbitrum as a more flexible Layer 2 platform for institutional and enterprise adoption, potentially strengthening its competitive position against other L2 networks as regulatory pressure on crypto infrastructure grows.

Compliance Filters: Off by Default, Opt-In for Orbit Chains

The compliance-filtering tools are designed exclusively for operators of dedicated Orbit chains — Arbitrum's customizable Layer 3 networks — who face regulatory obligations in their operating jurisdictions. Enforcement operates at two levels. The sequencer simulates transactions and rejects those that violate configured rules before they enter a block. For transactions submitted through the parent chain's Delayed Inbox, a sentinel can register the transaction hash with an onchain guardian so the state transition function forcibly fails it when included.

That second layer prevents a restricted user from bypassing the sequencer through Arbitrum's force-inclusion path. Restricted addresses are stored as salted hashes rather than plaintext, and the documentation recommends chains wait at least 30 days after the ArbOS 61 release before adopting the feature.

Priority Fees and Base Fee Administration

Elara gives dedicated-chain owners the ability to collect priority fees, or tips, but the feature ships disabled. Only the chain owner can turn collection on through the access-controlled ArbOwner precompile. Collecting tips alone does not change transaction ordering — a chain must also update its sequencer logic to sort using the priority-fee field.

For Arbitrum One's base fee, Elara introduces a BaseFeeManager contract that lets Offchain Labs adjust the minimum Layer 2 base fee within a DAO-approved range of 0.01 to 0.10 gwei. The delegation expires two years after mainnet activation, requires public notice through the Arbitrum forum, and can be removed by the DAO. The upgrade does not itself raise fees.

The alternative data-availability API is also aimed at dedicated chains, allowing operators to connect providers without maintaining custom Nitro forks. Arbitrum One is not expected to use it because its transaction data settles on Ethereum.

All node operators were required to upgrade to Nitro version 3.11.3 or higher before activation. The ArbitrumDAO approved the upgrade through its constitutional governance process, with the proposal first hitting the Arbitrum Sepolia testnet on June 29 — roughly seven weeks of testing before mainnet deployment.

The Elara upgrade strengthens Arbitrum's position in the L2 competitive landscape, where rivals like Optimism and Base continue to push developer tooling and institutional features. By offering compliance tooling for Orbit chains while keeping mainnet filters off, Arbitrum gives enterprise builders a path to regulatory alignment without compromising the permissionless nature of Arbitrum One.

This article is for informational purposes only and does not constitute investment advice.