Ethereum testnet explorer guide: Sepolia, Hoodi and beyond

The official list lives on the ethereum.org networks page, which is worth bookmarking because it is updated whenever a testnet is added or deprecated. Layer 2 teams run their own test networks on top of Sepolia, such as OP Sepolia, Base Sepolia and Arbitrum Sepolia. Those need rollup-specific explorers, which we cover in our layer 2 explorer guide.

Sepolia explorer options

Sepolia is where you test a dapp, a token or a contract upgrade before it touches real money. It started life as a proof-of-work chain (its genesis block is dated 3 October 2021), went through its own Merge in July 2022 and has followed every mainnet fork since, usually a few weeks ahead of mainnet. Its chain ID is 11155111, and by late September 2026 it was past block 11.7 million. The validator set is permissioned, run by client teams and infrastructure operators, which keeps the network stable and the state small enough to sync quickly.

sepolia.etherscan.io

The Etherscan Sepolia explorer is the default for most developers for one simple reason: contract verification works exactly as on mainnet, and Hardhat and Foundry plugins target it out of the box with the same Etherscan API V2 key. You get the Read and Write Contract tabs, event logs, internal transactions and the processed beacon withdrawals page. The downside is the same as on mainnet: a closed-source service with an account system and an API key requirement. Our full Etherscan review covers the free-tier limits that also apply to its testnet endpoints.

eth-sepolia.blockscout.com

Blockscout's Sepolia instance is the self-hostable alternative. It verifies contracts too, including via Sourcify, and its REST API works without a key, which is handy for CI pipelines and quick scripts. Blockscout tends to support new transaction types quickly, so when a fork introduces something new (blob transactions in 2024, EIP-7702 set-code transactions in 2025) you usually see it decoded on Blockscout early. This is also the data source behind our own tool.

Otterscan on Sepolia

The public Otterscan deployment gives you the fast, minimalist trace view that Otterscan fans love: call trees, gas profiles and raw storage changes without ads. Otterscan normally runs against your own Erigon or Reth node, so this public instance is mostly a convenience. If you want to run one locally, our open-source explorer guide walks through the setup.

Hoodi explorer for validators and staking

Hoodi is the youngest long-lived testnet. Its execution genesis is dated 17 March 2025, it activated the Pectra upgrade at epoch 2048 on 26 March 2025, and it uses chain ID 560048. It exists because Holesky broke (more on that below), and its job is to give stakers and node operators a place to test deposits, exits, consolidations and client upgrades with an open validator set. The Ethereum Foundation said at launch that Hoodi would be supported through 30 September 2028, and it was one of the three public testnets (after Holesky and Sepolia) to rehearse Fusaka in October 2025.

For execution-layer data, hoodi.etherscan.io and eth-hoodi.blockscout.com are the two big options, and hoodi.otterscan.io covers traces. For consensus-layer data, which is what you really care about as a validator, look at the ethPandaOps Hoodi beacon explorer or the Hoodi edition of beaconcha.in. Those show validator indexes, attestations, proposals and the deposit queue. We explain every field on those pages in our beacon chain explorer guide.

What happened to Holesky and its explorers

Holesky had an awkward life. Its first launch on 15 September 2023, the first anniversary of the Merge, failed because of a misconfigured genesis file, and it came back at the end of that month. It was designed to be big, with far more validators than mainnet, so client teams could stress-test at scale. For a while it was the go-to staking testnet.

Then came the Pectra activation in February 2025. A misconfiguration of the deposit contract address in several execution clients split the network and it lost finality. Recovery triggered extensive inactivity leaks, and the resulting exit queue was so long that, according to the EF, exited validators would take roughly a year to leave the set. A testnet where you cannot test the full validator lifecycle in reasonable time is not much use, so Hoodi was launched within weeks.

The shutdown announcement came on 1 September 2025. Holesky ran Fusaka on 1 October 2025 as a final rehearsal for mainnet, and most validator nodes were switched off two weeks after that fork finalized. Explorers followed. In our September 2026 check, holesky.etherscan.io no longer resolved and Blockscout's Holesky instance returned a 404. If you have an old Holesky transaction in a tutorial or a bug report, it is effectively unverifiable now.

Goerli, Ropsten and Rinkeby: a short history of retired testnets

Ethereum's testnet graveyard is instructive. Each network reflected the problems of its time, and each retirement pushed the ecosystem toward the current model of a few well-maintained networks with announced lifespans.

Ropsten was the most mainnet-like testnet for years, which was also its weakness. Proof of work with a tiny hash rate meant anyone with a few GPUs could reorganize it, and in early 2017 a spam attack with huge gas limits made it nearly unusable. It survived to become the first public testnet to run the Merge, then was retired at the end of 2022.

Rinkeby solved the attack problem with proof of authority, but only Geth could run it, so it was never a true multi-client test. It did not transition to proof of stake and was switched off in 2023. Kovan, the Parity-based equivalent, met the same fate.

Goerli was the workhorse of 2019 to 2023. Every major client could sync it, and after the Merge its Prater beacon chain made it the staking testnet too. Its undoing was economics. Goerli ETH had a fixed supply that dried up, faucets ran empty, and an informal market for "test ETH" appeared, which defeats the whole purpose. The EF announced its end, Dencun ran there in January 2024 as a final upgrade, and support stopped in April 2024. Holesky took over staking, and Sepolia took over apps.

The lesson the core developers drew is visible in how Hoodi and Sepolia are managed today: testnets get an announced lifespan and a successor is launched before the old one is switched off. That is annoying if you maintain tutorials, but far better than the old pattern of networks slowly rotting.

Faucets: where to get Sepolia and Hoodi ETH

You cannot buy test ETH, and you should not try. You get it from faucets, which ration it to stop bots draining them. The main options listed by ethereum.org in September 2026:

• PoW faucets by pk910 for Sepolia, Hoodi and Ephemery. Your browser does a bit of hashing work to earn a payout. It does not mint coins; the "mining" is only a spam filter. Slow but requires no account.
• Google Cloud Web3 faucet for Sepolia and Hoodi. Needs a Google account; daily amounts are small but reliable.
• Alchemy's Sepolia faucet, which asks that the receiving address hold at least 0.001 ETH on mainnet, a simple anti-bot check.
• Infura, QuickNode, Chainstack and Chain Platform run similar faucets, usually tied to a free developer account.

For Hoodi validator testing you need at least 32 test ETH per validator, more than most faucets hand out in one go. Check the Hoodi repository for the current way to request larger amounts rather than trusting a random Discord link.

Checking Sepolia and Hoodi in our live explorer

Our live Ethereum explorer supports Sepolia and Hoodi next to mainnet and Ethereum Classic. Open it, pick the network in the selector beside the search box, then paste a transaction hash, an address or a block number. The tool reads from the matching Blockscout instance, falls back to a public RPC node if that is slow, and shows the beacon slot and epoch for each block, calculated from the testnet's own genesis time. The "Open in" buttons jump to the same record on Etherscan or Blockscout if you need contract verification or deeper traces.

That makes it a quick sanity check when a deployment script says "success" but you want to see the receipt yourself, or when a teammate pastes a hash in chat and nobody knows which network it came from. Try the hash on mainnet first, then Sepolia, then Hoodi. One of them will answer.

Common mistakes: mainnet vs testnet

Searching the wrong network

By far the most frequent problem. A Sepolia transaction hash pasted into etherscan.io returns nothing, and people assume the transaction failed. Look at the network badge in your wallet, then use the explorer for that network. Addresses are the same format across all EVM networks, so an address search on the wrong network will "work", but show a different, often empty, balance. Our guide to reading transaction pages explains how to spot the network from the explorer header.

Assuming testnet gas behaves like mainnet

Testnet blocks are rarely full, so the base fee sits close to its floor. A transaction that costs a fraction of a cent on Sepolia can cost noticeably more on mainnet at a busy moment. Estimate real costs on our Ethereum gas tracker before you launch, not from testnet receipts.

Sending real ETH to a testnet address, or the reverse

Because the address is identical across networks, you cannot "send ETH to Sepolia" from an exchange. Exchanges only withdraw to mainnet (or a layer 2 they explicitly support). The funds land in the same address on mainnet, which is fine if you control that key, and a problem only if you gave someone an address you do not control. Conversely, test ETH cannot be deposited to an exchange at all; it simply does not exist there.

Hard-coding a testnet that is about to disappear

If your CI pipeline, docs or SDK defaults still reference Goerli or Holesky, they are broken already. Make the chain ID and RPC URL configuration, not code, and you will survive the next migration with a one-line change.

Which testnet explorer should you use?

For application work in 2026, use Sepolia with sepolia.etherscan.io if your tooling already speaks Etherscan, or eth-sepolia.blockscout.com if you prefer open source and keyless APIs. For staking and client testing, use Hoodi and pair an execution explorer with a beacon explorer. For throwaway experiments, Ephemery resets every 28 days and gets a new chain ID each time, so nothing you do there needs cleaning up. Treat everything else as history. And whenever something "disappears", check the network before you check anything else. If you want to compare the full-featured explorers side by side, our ranking of the best Ethereum explorers scores them on mainnet features that carry over to their testnet editions.