What is the gas limit for ERC-20 transfer?

The concept of gas limit is crucial in understanding the functioning of Ethereum transactions. It refers to the maximum amount of gas a user is willing to spend on a transaction. This ensures that transactions do not consume excessive computational resources and helps in maintaining the network's efficiency.

For a typical transaction involving the transfer of ETH or any Ethereum-based token, the gas limit is usually set at 21,000 gas units. This is considered the standard amount required to execute such transactions smoothly. The gas fee paid for these transactions goes to the miners who validate and add them to the blockchain.

However, when it comes to ERC-20 token approvals, the gas limit required is higher. An ERC-20 token approval transaction typically costs 45,000 gas units. This is because, in addition to transferring the token, the transaction also needs to interact with the smart contract governing the token, which requires more computational power.

Several blockchain networks, including those that are EVM-compatible, adopt a similar gas model. EVM stands for Ethereum Virtual Machine, and it allows smart contracts written for Ethereum to run on other blockchains. Harmony is one such blockchain that uses an identical gas model.

On Harmony, standard transactions, just like on Ethereum, also cost 21,000 gas units. This uniformity in gas limits helps in creating a seamless experience for users who are familiar with Ethereum's transaction model. It also allows developers to port their Ethereum-based applications to Harmony with minimal changes.