Understanding MetaMask’s Gas Limit Estimate for ERC20 Transfers
MetaMask, the popular Ethereum browser extension and dApp platform, relies on its API to facilitate transactions on the Ethereum blockchain. One of these APIs is the erc20.transfer() method, which allows users to transfer ERC-20 tokens (e.g. DAI, USDC) between wallets or contract addresses. However, in some cases, MetaMask may incorrectly estimate the gas cost for an ERC20 transfer, resulting in incorrect transaction processing.
In this article, we will look at why MetaMask limits the gas limit estimate to 100,000 and provide insight into the complexity of erc20.transfer() that contributes to these errors.
Why does MetaMask cap ERC20 .transfer() at 100,000?
The reason behind MetaMask’s estimated gas limit for erc20.transfer() is a combination of factors:
- Gas Estimation Algorithm: MetaMask uses an algorithm from the Ethereum Gas Estimator (EGE) library that estimates gas costs based on various factors such as network congestion, transaction complexity, and available gas on the network.
- Gas Price Fluctuations: Gas prices can fluctuate over time due to changes in network congestion, miner behavior, or other market factors. As a result, MetaMask may adjust its estimated gas limit upward to account for these price increases.
- Transaction Complexity:
erc20.transfer()involves multiple transactions (e.g., creating a new contract call and sending tokens), which can increase the complexity of the transaction. To deal with this complexity, MetaMask can assume that the total gas cost will be higher than the sum of the individual transaction costs.
Correct Estimated Gas Limit for ERC20 Transfers
In contrast to its incorrect estimate of 100,000 gas, the actual gas cost for an erc20.transfer() transaction can range from around 145,000 to over 300,000 gas units. This is because MetaMask’s algorithm takes into account the additional complexities involved in transferring tokens across multiple contracts.
Why does this matter?
Incorrectly calculating gas limits can lead to several problems, including:
- Failed Transaction: If a user attempts to transfer tokens that exceed the estimated gas limit, the transaction will fail and the user may not receive their funds.
- Delayed or dropped transactions: In some cases, MetaMask’s algorithm may calculate high gas costs, but the actual gas required for the transaction is lower. This can lead to delayed or dropped transactions, which can have significant consequences for the user experience.
Conclusion
MetaMask’s estimated gas limit of 100,000 for erc20.transfer() is incorrect due to its reliance on an algorithm that takes into account factors such as network congestion and fluctuations in gas prices. To avoid these errors, users should always check their transaction details after execution to ensure that the actual gas costs match their estimated value.
By understanding how MetaMask estimates gas limits and recognizing the complexities associated with `erc20.transfer() transactions, users can take steps to mitigate these issues and ensure a smooth user experience on the Ethereum blockchain.