eth_blockNumber on Fantom
Everything below was measured on 2026-10-13 by calling eth_blockNumber on Fantom 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 Fantom: what we measured
| Head block when measured | 123,672,412 (0x75f175c) |
|---|---|
| Age of that block when read | 1 s |
| Average block time (last 1,000 blocks) | 3.8 s |
| Median gap between newHeads over WebSocket | 10.2 s |
| "safe" behind the head | not available (invalid argument 0: hex string without 0x prefix) |
| "finalized" behind the head | not available (invalid argument 0: hex string without 0x prefix) |
What this means for polling
At 3.8 s per block, a one-second poll returns a new number on roughly one call in 4. Polling at the block time keeps you current without wasting requests.
Compared with other chains
Measured by the gap between WebSocket headers, Fantom has the 40th fastest block cadence of the 40 chains we measure.
Example request
curl -s https://rpc.swiftnodes.io/rpc/fantom?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/fantom?key=YOUR_API_KEY"),
});
const head = await client.getBlockNumber(); // bigint
// Follow the chain: poll about once per block (3.8 s on Fantom)
const unwatch = client.watchBlockNumber({
pollingInterval: 3833,
onBlockNumber: (n) => console.log("new head", n),
});Other methods on Fantom
- 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_transactionSupported
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
- 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
- Tempo
- Cronos
- Manta Pacific
- Shibarium
- Boba Network
- Arbitrum Nova
- Immutable zkEVM
Frequently asked questions
Does Fantom support eth_blockNumber?
Yes. eth_blockNumber answered on the SwiftNodes Fantom endpoint when our weekly probe called it through the customer path (2026-10-13).
How fast are blocks on Fantom?
About 3.8 s per block, averaged over recent blocks (measured 2026-10-13).
How often should I poll eth_blockNumber on Fantom?
About once per block, every 3.8 s. Faster polling mostly returns the same number.
Fantom endpoints, live block height and WebSocket status are on the Fantom RPC page.
One key covers every chain we serve, and SwiftNodes has a free tier.