Metamask: Solidity error: Unable to estimate gas; transaction may fail or may require manual gas limit

Metamask Errors in NextJS Applications with Solidity Contracts

As a modern web application developer, you are probably familiar with the importance of efficient and scalable blockchain integration. Metamask, a popular browser extension for interacting with Ethereum smart contracts, can sometimes cause issues when used in a NextJS application. One such issue is an error that occurs when executing transactions using Solidity contracts.

In this article, we will delve into the details of the “Cannot estimate gas” error and look at how to resolve it in a NextJS application with Metamask-compatible Solidity contracts.

What is the “Cannot estimate gas” error?

The error message indicates that Metamask is having difficulty estimating the amount of gas required for a transaction. This can cause problems during installation, as you may need to manually set the gas limit or rely on manual gas estimation tools such as [Etherscan’s Gas Estimator] (

Causes of the error

The “Gas not estimated” error typically occurs when the following conditions are met:

• Insufficient gas: The contract function requires an excessive amount of gas, which can be caused by complex logic or large data structures.

• Invalid gas limit: The gas limit set in Metamask may not be sufficient to successfully execute the transaction.

• Transaction complexity: Complex transactions with multiple inputs, outputs, or smart contracts can also lead to gas estimation errors.

How ​​to fix the error

To fix the “Cannot estimate gas” error, follow these steps:

1. Check the contract functionality and logic

Make sure your Solidity contract is correct and well-structured. Review the contract source code and verify that it complies with the Ethereum ABI (Application Binary Interface) guidelines.

2. Set the gas limit in Metamask settings

• Open the NextJS application settings.

• Navigate to the “Metamask” section.

• Find the “Gas limit” setting.

• Set a higher or lower gas limit than what the contract functionality requires.

Example:

// Increase gas limit by 20%
metamask: {
// ...
gas limit: 5000000,
// ...
}

3. Use manual gas estimators

In situations where Metamask cannot estimate gas, you may need to rely on external gas estimators such as [Etherscan’s Gas Estimator] ( This approach can be more accurate, but requires additional setup.

4. Optimize contract logic

To reduce the complexity of complex transactions and minimize gas usage:

• Simplify contract functions: Break down complex logic into smaller, more manageable functions.

• Use reusable components: Encapsulate common logic in reusable modules or libraries.

• Minimize data structures: Reduce the amount of data passed between contracts.

Example:

// Simplified contract function
function performTransaction() {
// ...
}

5. Monitor and adjust as needed

When deploying your NextJS application with Metamask-compatible Solidity contracts, continuously monitor gas usage and adjust settings as needed to ensure optimal performance.

If you follow these steps, you should be able to resolve the “Unestimable gas” error in your NextJS application using Metamask-compatible Solidity contracts. Remember to stay vigilant and adjust your approach as needed to optimize your blockchain integrations.

Conclusion

In this article, we explored the causes of the “Cannot estimate gas” error and provided actionable steps to resolve it when working with Solidity contracts in a NextJS application using Metamask. By following these tips, you will be better equipped to deliver efficient and scalable blockchain interactions in your NextJS applications.