The right explorer for Optimism, Arbitrum, Base, ZKsync, Scroll, Linea and Starknet, which ones changed or shut down in 2026, and how to follow a bridge withdrawal from L2 back to Ethereum.
By ethexplorer.org editorial team·Updated ·10 min read
A layer 2 explorer does for a rollup what Etherscan does for Ethereum: it turns a hash or an address into a readable page. The catch is that every rollup is its own chain, with its own blocks, its own explorer and sometimes its own address format. Paste a Base transaction into a mainnet explorer and you get “not found”, a classic source of panic for new rollup users. This guide pairs each major rollup with the explorers worth bookmarking, explains which services moved or disappeared in 2026, and shows how to follow funds across the bridge.
Rollups in two minutes: optimistic vs ZK
A rollup executes transactions off Ethereum, bundles them into batches and posts the data back to mainnet, since March 2024 mostly as blobs (our Ethereum blob explorer guide covers that layer). Ethereum then acts as the court of appeal. The two families differ in how they convince that court the batch is correct.
Optimistic rollups, such as OP Mainnet, Base and Arbitrum One, post their results and assume they are valid. Anyone watching can submit a fault proof during a challenge window, roughly a week, if a result is wrong. That design is simple and very EVM-compatible, but it means withdrawals back to Ethereum wait out the window.
ZK rollups, such as ZKsync Era, Scroll, Linea and Starknet, post a cryptographic validity proof with each batch. Once Ethereum verifies the proof, the state is final, so withdrawals take hours rather than days. The trade-off is heavier engineering, and in Starknet’s case a different virtual machine altogether.
For the explorer user, the practical differences are small. Every EVM rollup uses the same 42-character 0x addresses as Ethereum, and the same wallet key controls them all. What changes is the chain ID, the explorer domain and some extra fields, such as the L1 batch that included your transaction or an “L1 fee” line on the receipt.
Layer 2 explorers at a glance
Main layer 2 networks, their rollup type and the explorers we recommend (status checked 24 September 2026).
Stopped producing blocks July 2026; claims portal until end-2027
OP Mainnet: the “optimistic Ethereum explorer”
When the network launched in 2021, many people called it Optimistic Ethereum, and that is why Etherscan’s version still lives at optimistic.etherscan.io. The chain was simply “Optimism” for a while and was renamed OP Mainnet in June 2023 to separate it from the wider OP Stack ecosystem. So if you are searching for an Optimism Ethereum explorer or an optimistic Ethereum explorer, all three names point to the same chain.
Etherscan’s OP explorer feels exactly like mainnet Etherscan, with verified contracts, token pages and a gas tracker. The Blockscout alternative now sits at explorer.optimism.io (the old optimism.blockscout.com address redirects there) and adds a clean view of which L1 batch and blob carried each transaction. Both show the two-part fee on every receipt: the L2 execution fee and the L1 data fee the sequencer passes on. If Etherscan’s free API no longer covers OP Mainnet for your use case, the Blockscout API is keyless; see our explorer API comparison.
Arbitrum explorer options
Arbiscan is the default Arbitrum explorer and comes from the Etherscan team, so anyone who knows our Etherscan review will feel at home. A Blockscout instance at arbitrum.blockscout.com is the open-source alternative. Arbitrum One runs the BoLD dispute protocol, and the Arbitrum docs describe a dispute window of about 6.4 days, which the DAO can change. Arbitrum Nova, the cheaper sister chain for games and social apps, is a separate network: its old nova.arbiscan.io address now redirects to a Blockscout explorer, so update your bookmarks.
Base explorer: Basescan and Blockscout
Base, Coinbase’s rollup, is by far the busiest layer 2 in blob terms: Blobscan counts over 8 million blobs from Base alone. Its two explorers are Basescan (Etherscan) and base.blockscout.com. In February 2026 Base announced it would leave the Optimism Superchain and move to its own Base-operated stack. For explorer users nothing changed overnight: the domains, addresses and bridge flow stayed the same, and L2BEAT still classified Base as an optimistic rollup at Stage 1 in September 2026. It is worth watching, though, because withdrawal mechanics could change as the migration progresses.
ZK rollup explorers: ZKsync, Scroll, Linea and Starknet
ZKsync Era
The official ZKsync Era explorer is now the one to use; the Etherscan-built era.zksync.network address redirects to it. Transaction pages show which L1 batch included the transaction and whether that batch has been committed, proven and executed on Ethereum, which is the clearest way to see ZK finality in action. ZKsync’s docs list a minimum 3-hour execution delay before withdrawals finalise. In September 2026 the team announced that EraVM, the original virtual machine, would be retired within six months in favour of its newer Atlas stack, and recommended raising the delay on EraVM chains to 24 hours. Plain wallet balances needed no action, but check official ZKsync channels before moving large amounts.
Scroll
Scrollscan is Scroll’s main explorer; in our September 2026 check, scroll.blockscout.com redirected there too. Batches move from committed to finalized once the validity proof lands on Ethereum.
Linea
Linea, built by Consensys, the company behind MetaMask, has Lineascan from Etherscan and a Blockscout-powered explorer at explorer.linea.build. Both are fine; pick whichever layout you prefer.
Starknet
Starknet is the odd one out. It runs the Cairo VM rather than the EVM, and its addresses are 64 hex characters, so Ethereum explorers cannot read it at all. The two main explorers are Voyager, built by Nethermind, and Starkscan, which was live in September 2026 and now markets itself as a data API for developers and AI agents as much as an explorer. Starknet’s own website lists both, and Voyager is the older of the two.
Polygon zkEVM
Polygon zkEVM Mainnet Beta has been sunset. Polygon says the sequencer stopped on 3 July 2026 and the network no longer produces blocks. Assets held in an ordinary wallet can be claimed back on Ethereum through the Polygon zkEVM claims page until 31 December 2027, but funds locked inside smart contracts cannot be recovered. The old zkevm.polygonscan.com explorer did not load when we tested it. Polygon PoS is unaffected.
Tracking bridge deposits and withdrawals across L1 and L2
A bridge transfer is two transactions on two chains, and you need both explorers to see the whole trip.
Deposits (L1 to L2) are the easy direction. You send a transaction to the rollup’s bridge contract on Ethereum; look it up in a mainnet explorer such as our live Ethereum explorer. A few minutes later the rollup creates a matching deposit transaction on L2, credited to the same address. On OP Stack chains it appears as a special deposit transaction type; on Arbitrum it shows up as a retryable ticket. If the mainnet side succeeded but the L2 side has not appeared after twenty minutes, look up your address on the L2 explorer rather than the hash, because the L2 transaction has a different hash.
Withdrawals (L2 to L1) are where people get nervous. On an optimistic rollup such as OP Mainnet or Base, the flow has four stages:
1STEP 01
Start on L2
Your wallet sends a withdrawal transaction on OP Mainnet or Base. The L2 explorer shows it as a call to the bridge contract, confirmed within seconds.
2STEP 02
Prove on L1
Once the L2 state that includes your withdrawal has been posted to Ethereum (usually within an hour or so), you submit a “prove” transaction on mainnet. It appears in a mainnet explorer from your own address.
3STEP 03
Wait out the challenge window
Seven days in which anyone can dispute the posted state. Nothing appears on-chain during this time, which is why so many people think their funds are lost.
4STEP 04
Finalize on L1
After the window, send the “finalize” (or “claim”) transaction. Only now does the ETH or token land in your mainnet address, visible in any mainnet explorer.
Arbitrum is similar, minus the separate prove step: you wait roughly 6.4 days and then claim. ZK rollups skip the long wait, because once the proof and any execution delay have passed, the withdrawal can be finalised, usually within hours. Whichever bridge interface you used normally shows a status tracker, but the explorers are the source of truth. For reading the individual mainnet transactions, including the bridge contract call and its logs, our transaction explorer guide walks through each field.
Checking rollup risk with L2BEAT
An explorer tells you what happened; it does not tell you how safe the chain is. For that, L2BEAT is the standard reference. It rates rollups by stage: Stage 0 still relies heavily on its operators and security council, Stage 1 has working proofs with limited override powers, and Stage 2 is fully trustless. At the time of writing, L2BEAT listed Base, Arbitrum One, OP Mainnet and Starknet at Stage 1, and Linea, ZKsync Era and Scroll at Stage 0. It also tracks value secured, data availability and how quickly users could exit if the operator misbehaved.
We suggest a simple habit: before you park serious money on any L2, read its L2BEAT risk page, then use its explorer to confirm the bridge contract you are about to use is the one L2BEAT lists. For mainnet-side checks of those contracts, our smart contract explorer guide shows how to confirm verification and proxy status, and the best Ethereum explorers ranking compares the mainnet tools in depth. Testing on a rollup testnet first? Our testnet explorer guide covers Sepolia, whose L2 versions (such as sepolia-optimism.etherscan.io and sepolia.arbiscan.io) work the same way.
Frequently asked questions
5 Q&A
01
What is the Optimism Ethereum explorer?
OP Mainnet, the network once known as Optimistic Ethereum, has two main explorers: Etherscan’s version at optimistic.etherscan.io and a Blockscout instance at explorer.optimism.io (the old optimism.blockscout.com address redirects there). Both show transactions, tokens, verified contracts and L1 batch details.
02
Is there an Arbitrum explorer like Etherscan?
Yes. Arbiscan (arbiscan.io) is built by the Etherscan team and works the same way. There is also a Blockscout instance at arbitrum.blockscout.com. For Arbitrum Nova, the old nova.arbiscan.io address now redirects to a Blockscout explorer.
03
Which Base explorer should I use?
Basescan (basescan.org) for the familiar Etherscan layout, or base.blockscout.com if you want a self-hostable explorer with a keyless API. Base addresses are identical to your Ethereum addresses, so you can paste the same 0x… string. Our address explorer guide explains what each page shows.
04
Why does my withdrawal from Optimism, Base or Arbitrum take 7 days?
Optimistic rollups assume posted state is correct unless someone proves otherwise, and they give challengers a window to do so: 7 days on OP Mainnet and Base, about 6.4 days on Arbitrum One. After the window you must send a final claim transaction on Ethereum. Third-party bridges can pay you out sooner in exchange for a fee.
05
Can I see layer 2 transactions on the Ethereum mainnet explorer?
Not individually. A mainnet explorer shows the rollup’s batch transactions and the blobs they carry, not your L2 swap. Use the L2’s own explorer for that, and a blob explorer if you want to see the data the rollup posted to Ethereum.