Why Is HardHat Mainnet Fork Always Behind By Roughly 5 Blocks?

Question

Whenever I do a fork on mainnet at latest with hardhat, it's never at the latest block. Why is that? For example in the below:

    console.log("BLOCK FRO ALCHEMY: ", (await alchemyEthProvider.getBlock("latest")).number); //block N
    console.log("BLOCK FROM HARDHAT", (await hardhatProvider.getBlock("latest")).number); //block N-5

The hardhat settings for mainnet forking just uses the same provider as alchemyEthProvider above, so it's sourced from the same provider, ultimately. But for some reason, forking is a bit slower.

Answer 1

There are a couple key factors here:

• you're forking "from" mainnet, not on it
• a data/code "fork" is just like a fork in the road; one continues to the left and another to the right

This is why the fork cannot match mainnet, because it's now a completely different road and is effectively its own network.