eth_blockNumber on Tempo
Everything below was measured on 2026-10-13 by calling eth_blockNumber on Tempo 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 Tempo: what we measured
| Head block when measured | 43,950,874 (0x29ea31a) |
|---|---|
| Age of that block when read | 2 s |
| Average block time (last 1,000 blocks) | 576 ms |
| Median gap between newHeads over WebSocket | 553 ms |
| "safe" behind the head | 0 blocks |
| "finalized" behind the head | 0 blocks |
What this means for polling
Tempo produces a block about every 576 ms, so a client that polls eth_blockNumber once a second sees the number jump by about 2 each time. If you need every block, subscribe to newHeads over WebSocket (see eth_subscribe on Tempo) or fetch the skipped range with eth_getBlockByNumber.
"finalized" pointed at the head block itself on Tempo: its nodes report each new block as finalized, so the tag adds no safety over "latest". If you need settlement on Ethereum or protection from deep reorgs, check Tempo's own finality rules rather than the tag.
Compared with other chains
Measured by the gap between WebSocket headers, Tempo has the 9th fastest block cadence of the 40 chains we measure.
Example request
curl -s https://rpc.swiftnodes.io/rpc/tempo?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/tempo?key=YOUR_API_KEY"),
});
const head = await client.getBlockNumber(); // bigint
// Follow the chain: poll about once per block (576 ms on Tempo)
const unwatch = client.watchBlockNumber({
pollingInterval: 576,
onBlockNumber: (n) => console.log("new head", n),
});Other methods on Tempo
- 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_subscribeSupported
- eth_getLogsSupported
- eth_getBlockReceiptsSupported
- eth_feeHistorySupported
- eth_getProofSupported
- eth_createAccessListSupported
- debug_traceCallSupported
- trace_blockSupported
- trace_transactionNot measured
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
- Mode
- Flare
- Core
- Chiliz
- Telos EVM
- Cronos
- Manta Pacific
- Shibarium
- Boba Network
- Arbitrum Nova
- Immutable zkEVM
Frequently asked questions
Does Tempo support eth_blockNumber?
Yes. eth_blockNumber answered on the SwiftNodes Tempo endpoint when our weekly probe called it through the customer path (2026-10-13).
How fast are blocks on Tempo?
About 576 ms per block, averaged over recent blocks (measured 2026-10-13).
How often should I poll eth_blockNumber on Tempo?
Polling cannot keep up with 576 ms blocks; subscribe to newHeads over WebSocket instead.
Tempo endpoints, live block height and WebSocket status are on the Tempo RPC page.
One key covers every chain we serve, and SwiftNodes has a free tier.