An EVM-compatible Layer 2 optimistic rollup testnet on Ethereum Sepolia, OP Stack-based, OP Sepolia enables fast, low-cost dApp and infrastructure testing with ETH gas.
OP Sepolia is Optimism’s Layer 2 rollup test network for the OP Stack, anchored to Ethereum Sepolia and using ETH as its native token. It lets developers safely test EVM‑equivalent smart contracts, cross‑chain bridging (Standard Bridge), wallets, oracles, and protocol upgrades before mainnet, with faucet ETH and production‑like infrastructure (sequencer and fault‑proofs). For planning and benchmarking, OP Sepolia typically targets ~2s L2 blocks, negligible L2 gas costs (faucet‑funded), bursty developer‑driven activity, and benchmark throughput in the 100+ TPS range depending on data availability.
OP Sepolia stands out with OP Stack EVM‑equivalence and the Bedrock architecture, delivering near‑identical behavior and tooling to OP Mainnet while inheriting security and data availability from Ethereum Sepolia. Compared with L1 testnets like Ethereum Sepolia (~12s blocks, <20 TPS, higher gas), OP Sepolia offers faster blocks (~2s), far lower fees (negligible on testnet), and higher throughput (peaks 100+ TPS), plus seamless interoperability with other OP Stack chains for cross‑chain testing. This makes it ideal for realistic performance, bridging, and fault‑proof validation without mainnet costs.
OP Sepolia Testnet uses ETH as the gas token for transaction fees. You can obtain ETH by bridging from other chains or purchasing using thirdweb Bridge, or through faucets (for testnet).
To bridge ETH to OP Sepolia Testnet, connect your wallet to thirdweb bridge, select your source chain, choose the token you want to bridge, select OP Sepolia Testnet as the destination, enter the amount, and confirm the transaction. The bridge will handle the cross-chain transfer instantly.
To build on OP Sepolia Testnet you can use thirdweb, which provides an easy way to build, monetize and scale your apps, games or agents. You can find detailed guides and documentation on https://portal.thirdweb.com to get started quickly.
To add OP Sepolia Testnet to your wallet, you can connect your wallet and click on [Add to Wallet] button at the top of the page. Alternatively, you can add the network manually using the RPC URL and chain details and add it to your wallet's network settings.
To send ETH on OP Sepolia Testnet, ensure your wallet is connected to the OP Sepolia Testnet network, enter the recipient's address, specify the amount of ETH to send, review the gas fee, and confirm the transaction in your wallet.
