RPC method

eth_getBlockByNumber on Core

Supported on SwiftNodes

Everything below was measured on 2026-10-13 by calling eth_getBlockByNumber on Core through the same endpoint customers use, and is re-measured weekly.

What eth_getBlockByNumber does

Returns a block by number or tag (latest, safe, finalized, pending, earliest): the header, and either the transaction hashes or the full transactions. Indexers, explorers and wallets use it to follow the chain.

eth_getBlockByNumber on Core: what we measured

Header fields	28 (1 beyond the Ethereum set)
Transactions per block	1, 1, 2, 1, 1 in five consecutive blocks
Response size, full transactions (true)	3.1 KB average
Response size, hashes only (false)	2.4 KB
Gas limit	50,000,000
Gas used in the latest block	26,280 (0.053% of the limit)
Base fee	0 wei
Tag "safe"	block 39,528,227
Tag "finalized"	block 39,528,227
Tag "pending"	block 39,528,229
Tag "earliest"	block 0

What is different on Core

Core blocks carry a field that Ethereum blocks do not. milliTimestamp: specific to this chain's node software, not part of the Ethereum JSON-RPC specification. Strict schema validators need to allow it.

The header includes the fields added by London (EIP-1559 base fee), Shanghai (withdrawals), Cancun (EIP-4844 blob gas), Cancun (EIP-4788 beacon root), Prague (EIP-7685 requests). Code that assumes Ethereum's current header shape will parse it as is.

A real Core block header

From block 39,528,226, as our endpoint returned it (long hex values shortened).

{
  "baseFeePerGas": "0x0",
  "blobGasUsed": "0x0",
  "difficulty": "0x2",
  "excessBlobGas": "0x0",
  "extraData": "0xd98301001a846765…(280 bytes)",
  "gasLimit": "0x2faf080",
  "gasUsed": "0x66a8",
  "hash": "0x85a10514cee5dadacd01b9b48b482b0f74b02f8aa0599cbe6a169654fbac5494",
  "logsBloom": "0x0000000000000000…(256 bytes)",
  "milliTimestamp": "0x1a1354dc2b8",
  "miner": "0x729f39a54304fcc6ec279684c71491a385d7b9ae",
  "mixHash": "0x0000000000000000000000000000000000000000000000000000000000000000",
  "nonce": "0x0000000000000000",
  "number": "0x25b2722",
  "parentBeaconBlockRoot": "0x0000000000000000000000000000000000000000000000000000000000000000",
  "parentHash": "0xa3ade7ab09b45949aabb575c9c7cb9a96c6e15992fa289418de0c39bb730c062",
  "receiptsRoot": "0x09187b1f7de996580fce521eb91e07536fcc2381c907ab3e86349a96088398ee",
  "requestsHash": "0xe3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855",
  "sha3Uncles": "0x1dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a142fd40d49347",
  "size": "0x410",
  "stateRoot": "0x805054808b1329a1546f63004ac2b17d0a5e702a48114b71c768ab1fdf678ba1",
  "timestamp": "0x6ace2863",
  "totalDifficulty": "0x4b4ef76",
  "transactions": "1 transactions",
  "transactionsRoot": "0xe39c730873de540e0203dba4fd1aa1bb986ade5970d7c5b45f7520fff4cc03d2",
  "uncles": [],
  "withdrawals": [],
  "withdrawalsRoot": "0x56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421"
}

Example request

curl -s https://rpc.swiftnodes.io/rpc/core?key=YOUR_API_KEY \
  -X POST -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","id":1,"method":"eth_getBlockByNumber","params":["latest",false]}'

import { createPublicClient, http } from "viem";

const client = createPublicClient({
  transport: http("https://rpc.swiftnodes.io/rpc/core?key=YOUR_API_KEY"),
});

// Header plus transaction hashes (2.4 KB)
const block = await client.getBlock({ blockTag: "latest" });

// With full transactions (3.1 KB on average on Core)
const full = await client.getBlock({ blockNumber: block.number, includeTransactions: true });

// A block that will not be reorganised
const final = await client.getBlock({ blockTag: "finalized" });

Other methods on Core

eth_getBlockByNumber on other chains

Frequently asked questions

Does Core support eth_getBlockByNumber?

Yes. eth_getBlockByNumber answered on the SwiftNodes Core endpoint when our weekly probe called it through the customer path (2026-10-13).

How many transactions are in each Core block?

In five consecutive blocks on 2026-10-13: 1, 1, 2, 1, 1.

What are milliTimestamp in a Core block?

milliTimestamp is not part of the Ethereum JSON-RPC specification; added by this chain's node software.

Core endpoints, live block height and WebSocket status are on the Core RPC page.

One key covers every chain we serve, and SwiftNodes has a free tier.