eth_blockNumber on Mode
Everything below was measured on 2026-10-13 by calling eth_blockNumber on Mode through the same endpoint customers use, and is re-measured weekly.
What eth_blockNumber does
Returns the number of the most recent block the node has, as a hex string. It is the cheapest way to tell whether a node is keeping up and the usual starting point for polling a chain.
eth_blockNumber on Mode: what we measured
| Head block when measured | 45,864,086 (0x2bbd496) |
|---|---|
| Age of that block when read | 2 s |
| Average block time (last 1,000 blocks) | 2.0 s |
| "safe" behind the head | 548 blocks (about 18 min) |
| "finalized" behind the head | 546 blocks (about 18 min) |
What this means for polling
At 2.0 s per block, a one-second poll returns a new number on roughly one call in 2. Polling at the block time keeps you current without wasting requests.
The number eth_blockNumber returns is the newest block, which can still change in a reorg. On Mode, "finalized" was 546 blocks (about 18 min) behind it and "safe" 548 blocks behind. Use eth_getBlockByNumber("finalized") when you need a height that will not change.
Example request
curl -s https://rpc.swiftnodes.io/rpc/mode?key=YOUR_API_KEY \
-X POST -H "Content-Type: application/json" \
-d '{"jsonrpc":"2.0","id":1,"method":"eth_blockNumber","params":[]}'import { createPublicClient, http } from "viem";
const client = createPublicClient({
transport: http("https://rpc.swiftnodes.io/rpc/mode?key=YOUR_API_KEY"),
});
const head = await client.getBlockNumber(); // bigint
// Follow the chain: poll about once per block (2.0 s on Mode)
const unwatch = client.watchBlockNumber({
pollingInterval: 2000,
onBlockNumber: (n) => console.log("new head", n),
});Other methods on Mode
- eth_chainIdSupported
- eth_getBalanceSupported
- eth_getBlockByNumberSupported
- eth_getTransactionByHashSupported
- eth_getTransactionReceiptSupported
- eth_callSupported
- eth_estimateGasSupported
- eth_gasPriceSupported
- eth_maxPriorityFeePerGasSupported
- eth_sendRawTransactionSupported
- eth_getTransactionCountSupported
- eth_getCodeSupported
- eth_subscribeNot available
- eth_getLogsSupported
- eth_getBlockReceiptsSupported
- eth_feeHistorySupported
- eth_getProofSupported
- eth_createAccessListSupported
- debug_traceCallSupported
- trace_blockSupported
- trace_transactionNot available
eth_blockNumber on other chains
- Ethereum
- Base
- Arbitrum
- Optimism
- Polygon
- BNB Smart Chain
- Avalanche
- Sonic
- Linea
- Scroll
- zkSync Era
- Blast
- Mantle
- Gnosis
- Celo
- Berachain
- Monad
- Unichain
- Kaia
- PulseChain
- World Chain
- Ronin
- Abstract
- ApeChain
- MegaETH
- Fantom
- Lisk
- Hemi
- X Layer
- BOB
- Plasma
- Fraxtal
- Zora
- Story
- Soneium
- Sei
- Hyperliquid
- Taiko
- Morph
- Ink
- Katana
- Ethereum Classic
- opBNB
- Flare
- Core
- Chiliz
- Telos EVM
- Tempo
- Cronos
- Manta Pacific
- Shibarium
- Boba Network
- Arbitrum Nova
- Immutable zkEVM
Frequently asked questions
Does Mode support eth_blockNumber?
Yes. eth_blockNumber answered on the SwiftNodes Mode endpoint when our weekly probe called it through the customer path (2026-10-13).
How fast are blocks on Mode?
About 2.0 s per block, averaged over recent blocks (measured 2026-10-13).
How often should I poll eth_blockNumber on Mode?
About once per block, every 2.0 s. Faster polling mostly returns the same number.
Mode endpoints, live block height and WebSocket status are on the Mode RPC page.
One key covers every chain we serve, and SwiftNodes has a free tier.