Base vs Ethereum block explorers

TLDR

Base is an Ethereum L2 rollup built on the OP Stack. It shares Ethereum's address format, the EVM runtime, and the same wallet UX, but it is a distinct chain with its own state, its own fees, and its own explorer. tx.taxi routes Ethereum lookups to Etherscan and Base lookups to BaseScan.

Address & transaction format

Both Ethereum and Base use the same address format because they are both EVM chains. An address is 20 raw bytes shown as 0x followed by 40 hex characters. EIP-55 mixed-case checksums are the same on both. Crucially, the same private key controls the same address on both chains, which is why your wallet can show Ethereum and Base balances side by side without any address translation.

Transaction hashes are also identical in shape: 32 bytes of Keccak-256 over the signed transaction, shown as a 66-character 0x-prefixed hex string. Block hashes share the format. Block numbers are integers.

The key difference is chain context. Ethereum mainnet uses chain ID 1; Base uses chain ID 8453. The chain ID is part of the signed transaction (EIP-155), so a transaction signed for chain 1 cannot be replayed on chain 8453. This is why the same 0x address can have completely different histories on Ethereum and Base: each chain processes only transactions signed against its own chain ID.

A bare hex address tells you nothing about which chain it has activity on. A transaction hash uniquely identifies a transaction within one chain but is theoretically possible (with vanishingly small probability) on multiple chains. In practice, a given tx hash exists on exactly one chain, but you need to know which.

Block explorers tx.taxi uses

For Ethereum, tx.taxi's primary configured explorer is Etherscan. Etherscan is a long-running, widely-used Ethereum explorer with deep coverage of contract verification, internal transactions, token transfers, and event logs.

For Base, tx.taxi's primary configured explorer is BaseScan. BaseScan is built on the same explorer family and provides the equivalent feature set scoped to the Base chain: Base addresses, Base transactions, Base contracts, and L2-specific data such as the L1 batch that included a given L2 transaction.

Because both explorers share UI conventions, switching between them is low-friction. The data they index is independent.

When to use which

If you know the value came from a Base transaction (a swap on a Base-deployed DEX, a mint of a Base NFT, an L2 send), use the Base chain page which routes to BaseScan. If it came from an Ethereum mainnet action, use the Ethereum chain page which routes to Etherscan.

For ambiguous 0x addresses, tx.taxi routes to a multichain aggregator so you can see which chains the address has activity on, then drill into the chain-specific explorer. For transaction hashes, if you found the hash in a Base-aware wallet view, it is a Base hash; if you found it on an Ethereum mainnet receipt, it is an Ethereum hash. Pasting a Base tx hash into Etherscan returns no result, and vice versa.

See how to read a transaction hash and EVM vs Solana addresses for related background.

Common confusions

The first confusion is shared addresses, independent state. Users routinely assume that because their address looks the same on Ethereum and Base, the balances and transactions are unified. They are not. Your ETH on Ethereum and your ETH on Base are independent balances. Bridging is a real transaction, not a view change. BaseScan will not show your Ethereum mainnet history; Etherscan will not show your Base activity.

The second confusion is gas token. Base uses ETH as its native gas token, the same symbol as Ethereum. Looking at a transaction on BaseScan, the "value" and "fee" columns are denominated in ETH, but it is bridged ETH on the L2, not L1 ETH. The accounting is different even though the unit looks the same.

The third confusion is finality and L1 commitment. A Base transaction is included in a Base block in about two seconds, but final settlement back to Ethereum L1 takes longer because the rollup posts batches periodically. BaseScan exposes the L1 batch metadata; Etherscan does not, because from Ethereum's view those batches are just calldata-bearing transactions to the Base rollup contracts. For most lookups this distinction does not matter; for cross-domain debugging it does. Either way, tx.taxi delivers you to the explorer that knows the answer.