eth_blockNumber on Arbitrum One
Returns the latest block height the node has synced. The cheapest and most common health/poll call — used to confirm an endpoint is live and at chain tip.
Because it only reads the head, it's the ideal liveness/lag probe: poll it and compare against a second source to catch a stalled or forked node. It takes no block tag and answers instantly even on pruned nodes.
Arbitrum One endpoint (public — no key)
https://rpc.nodeflare.app/arb/publicMethod
eth_blockNumber
Cost
1 CU
Chain ID
42161
Block time
~250 ms
Finality
<1 s sequencer · L1-final ~13 min
Blocks on Arbitrum One
Arbitrum produces blocks on demand, as fast as ~250 ms apart — the fastest cadence of any chain we serve. block.number is the L2 block; a single day can span hundreds of thousands of blocks.
Parameters
None.cURL
curl https://rpc.nodeflare.app/arb/public \
-X POST \
-H 'content-type: application/json' \
-d '{"jsonrpc":"2.0","method":"eth_blockNumber","params":[],"id":1}'ethers.js
import { ethers } from 'ethers';
const provider = new ethers.JsonRpcProvider(
'https://rpc.nodeflare.app/arb/public'
);
const result = await provider.send('eth_blockNumber', []);Try it live
Runs the example above against the public Arbitrum One endpoint — straight from your browser.
eth_blockNumber on Arbitrum One — FAQ
How do I call eth_blockNumber on Arbitrum One?
POST a JSON-RPC 2.0 request with "method": "eth_blockNumber" to NodeFlare's Arbitrum One endpoint at https://rpc.nodeflare.app/arb/public. No API key is required for the public endpoint.
What does eth_blockNumber cost on the free tier?
eth_blockNumber is weighted at 1 compute unit per call. The free tier includes 2,000,000 CU/month, so that is roughly 2,000,000 eth_blockNumber calls per month — no credit card.
Is eth_blockNumber available on the public Arbitrum One endpoint?
Yes. eth_blockNumber works on the public Arbitrum One endpoint (https://rpc.nodeflare.app/arb/public) with no API key, rate-limited per IP. A free key adds higher limits and a dedicated path.
Anything Arbitrum One-specific to know when using eth_blockNumber?
Arbitrum produces blocks on demand, as fast as ~250 ms apart — the fastest cadence of any chain we serve. block.number is the L2 block; a single day can span hundreds of thousands of blocks.
Call eth_blockNumber on Arbitrum One with a free key
2,000,000 compute units/month, heavy methods unlocked, every chain included. No credit card.
Get your free API key →