I have configure my project with nomiclabs hardhat-etherscan and hardhat.config.ts with sepolia network as goerli network as high gas fees.

I could also deploy the contract with hardhat.config.ts but I am unable to verify the contract on sepolia test network.

Deployed Contract Address: 0x6Fc8481F93Ae4725DA1120BBEF6B1E593F7956c4

Here's my hardhat.config.ts

 etherscan: {
    apiKey: process.env.ETHERSCAN_API_KEY

if (process.env.NETWORK_SEPOLIA_URL !== undefined) {
  console.log("Using Sepolia network");

  config.networks!.testnet = {
    url: process.env.NETWORK_SEPOLIA_URL,
    accounts: [process.env.SEPOLIA_PRIVATE_KEY!],

I am using command hardhat verify --constructor-args config/ContractArguments.ts

Here's ContractArguments.ts

import { utils } from "ethers";
import CollectionConfig from "./CollectionConfig";

// Update the following array if you change the constructor arguments...
const ContractArguments = [
] as const;

export default ContractArguments;

Error: Error in plugin @nomiclabs/hardhat-etherscan: Unsupported network ("sepolia", chainId: 11155111).

  • Hey, Did you get a solution for this? Commented Apr 26, 2023 at 5:15

3 Answers 3


I faced a similar error, but updating @nomiclabs/hardhat-etherscan to the latest version worked for me.

npm update @nomiclabs/hardhat-etherscan
  • I am using @nomiclabs/hardhat-etherscan 3.1.7 version Commented Mar 31, 2023 at 6:17

I faced the same issue while verifying my contract using [hardhat-etherscan] so I updated the package using this command in the console >>> npm update @nomiclabs/hardhat-etherscan

This worked for me, you can give it a try too!


As your error says, Sepolia is not supported by hardhat-etherscan

  • I know it's not supported but when you check hardhat documentation they've provided configuration for sepolia network. I have followed them as is but still it doesn't work. Commented Mar 28, 2023 at 6:49

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