2026 L2 Builder Guide — How to Choose Between Arbitrum, Base, Scroll, and GIWA

The Ethereum Layer 2 ecosystem has moved well beyond simply competing for lower gas fees. Each chain is now building its own unique technical architecture through independent execution client revamps, engine-level native account abstraction, and shifts toward zero-knowledge virtual machines.

We are now in an era where the chain a developer chooses fundamentally dictates the designable smart contract structure and end-user experience. This guide compares the technical goals and real-world development environments of key L2s in 2026 to help you select the network best suited for your business objectives.

Arbitrum One: A High-Performance DeFi Powerhouse Armed with BoLD and Stylus

As of 2026, Arbitrum One maintains an overwhelming DeFi ecosystem while maximizing technical decentralization and computational efficiency. The most significant changes for developers are the mainnet launch of the BoLD (Bounded Liquidity Delay) dispute resolution system and the full-scale activation of the Stylus architecture.

BoLD resolves the reliance on a Security Council, which was previously a bottleneck for Layer 2s. Now, anyone can participate in the fraud-proof dispute game without the intervention of specific trusted entities, achieving full Stage 1 decentralization. Alongside this, the ArbOS 51 'Dia' upgrade introduced multi-resource gas metering and secp256r1 passkey support, significantly lowering signature verification costs.

The most powerful weapon for developers is Stylus, a WebAssembly execution environment. It allows smart contracts written in Rust, C, and C++ to run on the same virtual machine alongside Solidity. Stylus offers up to 70x improved computational performance while bringing base gas fees down to the 0.02 gwei range.

If you are working on on-chain derivative models or cryptographic libraries requiring complex computations, a Stylus and Rust combination is the ideal choice. It allows you to implement sophisticated financial logic previously abandoned due to gas constraints, all while maintaining perfect EVM compatibility.

OP Stack and Base: op-reth Migration and Native AA Without Bundlers

The OP Stack ecosystem has shifted fully to a high-performance execution client system based on Rust, starting with the Karst hard fork. By officially ending support for op-geth and mandating migration to the execution engine op-reth and the fault-proof-supporting kona-client, infrastructure performance has soared, and a robust architectural foundation now exists to enhance the execution engine directly at the node level.

Base is the most aggressive adopter of these changes. Through the Cobalt hard fork, Base drives EIP-8130 and EIP-8140 directly within the Reth V2 engine to implement native account abstraction. It removes the complex bundler networks and EntryPoint contract calls required by traditional ERC-4337, shifting to a structure where nodes verify and process transactions directly.

The resulting gas savings and user experience improvements are massive. Using the dedicated 0x79 transaction type, standard USDC transfer gas fees plummet from 125,000 to around 46,000—a 63% reduction—providing a seamless experience comparable to Web2 payments. Because gas sponsorship and token payments are handled at the protocol level, developers can immediately implement fully non-custodial mobile wallet services using passkeys without managing gas relay servers. Developers can test this innovative native gas reduction logic right now on the Base Vibenet devnet.

Scroll: A Stage 1 zkRollup That Mastered Speed with OpenVM

Starting with the Euclid upgrade, Scroll fully transitioned its existing Halo2 circuit architecture to OpenVM, a RISC-V-based general-purpose zkVM. Instead of manually designing complex zero-knowledge circuits, developers can now use standard compiler environments, making the generation and management of virtual machine-level execution proofs much simpler.

The most crucial architectural change is the shift of the state commitment structure from the existing zktrie to the Ethereum-native MPT. This ensures perfect data consistency with the mainnet, allowing developers to use existing Ethereum infrastructure and state analysis tools on Scroll without additional data conversion or specialized libraries.

Along with the transition to native MPT, the block time has been reduced to 1 second to ensure high-speed pre-confirmation. By meeting the Stage 1 zkRollup requirements—which reduce dependence on the Security Council—Scroll provides added technical completeness, making it suitable for products where minimizing trust assumptions and achieving immediate finality via ZK proofs are critical, such as financial transactions or enterprise-facing services.

GIWA Chain: An OP Stack L2 Specialized for Enterprise Compliance and Privacy

GIWA Chain, built by Dunamu, is a standalone Layer 2 network applying the OP Stack Enterprise 'Self-Managed' license. Designed for enterprise compliance and regulatory adherence, it opens the Sepolia testnet (Chain ID 91342) and integrates with Nodit's faucet infrastructure to support a free testing environment for the public developer ecosystem. However, the mainnet, where commercial business will operate, is a closed, whitelisted environment where only authorized institutional partners can execute transactions; therefore, network permissions and access control logic must be clearly separated from the development stage.

Key differentiators for developers are GIWA’s unique compliance middleware protocols, 'Dojang' and 'Bojagi.' Based on the Ethereum Attestation Service (EAS), 'Dojang' maps Upbit’s real-name verification status to smart contracts as a cryptographic proof without exposing sensitive personal information on-chain. The 'Bojagi' zero-knowledge proof layer hides transaction parties' information and asset flows, helping to maintain compliance while ensuring enterprise-grade financial privacy.

Infrastructure performance has also been optimized. It reduces the standard OP Stack's 2-second block time to 1 second and includes Flashblocks to guarantee rapid pre-confirmation speeds of under 200ms. Since the Karst hard fork, the execution client has been fully replaced with the high-performance, Rust-based op-reth. Leveraging these high-performance, low-latency characteristics and privacy-preserving capabilities, it has successfully completed PoC tests for cross-border remittances and trade settlements with partners like Hana Financial Group, proving its potential as a financial infrastructure alternative.

Common Mistakes and Misconceptions When Building on L2

Do not confuse the sub-millisecond high-speed pre-confirmation offered by L2 sequencers with the finality of the Ethereum mainnet. Pre-confirmation is merely a 'soft confirmation' step where the sequencer promises inclusion in a block; it is not the same as 'hard finality' approved by validators. For security-critical operations, such as high-value asset transfers or large-scale DeFi trades, you must implement state-detection logic that safely waits until the block status is fully recorded on the mainnet.

Although most L2s claim EVM equivalence, subtle differences exist in the actual runtime Opcode environment. For example, some L2 virtual machines do not provide environment variables like BLOCKHASH or PREVRANDAO, or they return values structured completely differently from the mainnet. Specifically, if you build contracts using development tools that default to the latest mainnet hard fork opcodes, transactions may be rejected instantly on L2 nodes that do not support them, so you must carefully tune your compilation target version.

Discrepancies in sequencer gas measurement formulas between testnets and mainnets are another common cause of failure. Testnets have low traffic and generous gas calculation rates, allowing transactions to pass smoothly, but mainnets face dynamically surging DA (Data Availability) costs—the cost of recording data to L1. It is safer to avoid hard-coding SDK gas limits and instead use defensive design by integrating with the execution node's real-time gas estimation API to calculate fees dynamically.

Summary of L2 Recommendations and Builder Guide by Business Model

If you are building high-performance DeFi infrastructure and require extreme computational optimization, Arbitrum One is the most certain choice. You can leverage the Stylus architecture to deploy high-performance smart contracts in Rust and build robust on-chain trust on top of the fully permissionless fraud-proof system guaranteed by BoLD. Conversely, if your priority is a seamless experience on par with Web2 mobile apps, using passkey logins and bundler-free gas sponsorship, Base is the right fit as it supports EIP-8130 native account abstraction at the execution engine level.

If you want to maintain EVM bytecode compatibility while benefiting from zero-knowledge security, Scroll is worth considering. Since the Euclid upgrade, it has transitioned to an OpenVM system, dramatically boosting ZK proof generation performance, and it shares a native MPT structure, providing excellent state consistency with the mainnet. This allows development teams to secure a stable Stage 1 rollup environment without wasting resources on complex ZK circuit design.

Finally, for enterprise environments that require a combination of strict regulatory compliance and privacy protection, such as corporate finance or supply chain distribution, you should explore GIWA Chain. In the public Sepolia testnet (Chain ID 91342) environment, which is fully equipped with Nodit faucets, you can pre-test designs that combine the Ethereum-based identity protocol 'Dojang' and the zero-knowledge privacy engine 'Bojagi' module. It is an ideal testbed to conduct a perfect PoC before deploying to a private mainnet where only authorized partners execute transactions.

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