BigNumber Overflow in Metamask Ether.js – A Troubleshooting Guide for Smart Contracts

As a developer working with DeFi applications, you’ve likely encountered issues related to large numbers and wei conversions. In this article, we’ll dive deeper into the BigNumber overflow issue when using Metamask on Ethereum, specifically with regards to ether.js.

The Problem

When a user attempts to input an amount greater than 999 into their wallet, a BigNumber overflow error is triggered. This is because BigNumber.js expects numbers within a certain range (typically between -2^53 and 2^53) before triggering an overflow. When the input exceeds this range, the result is repeated, resulting in incorrect conversions.

The Problem with BigNumber in Ether.js

Ether.js provides a BigNumber implementation that allows for arbitrary precision arithmetic. However, when using Metamask on Ethereum, the BigNumber library is not designed to handle large numbers efficiently. This can lead to performance issues and ultimately an overflow error.

Solution: Use Decimal.js or another BigNumber library

To avoid the BigNumber overflow issue, it is recommended to use a library more suited for number handling in your smart contract. Two popular alternatives are:

• Decimal.js – A JavaScript library that provides support for decimal arithmetic up to 1024 digits. You can easily replace BigNumber.js with Decimal.js in your code.

• BNP.js – Another popular BigNumber implementation designed specifically for Ethereum.

Here is an example of how you could modify your contract to use BNP.js:

import { BN } from '@bnpjs/bn-polyfill';
// Define variables
const amount = new BN('0x123456789012345678901234567890');
// Perform the conversion and store the result
new BNB().getDecimalAmount(amount);

Best practices

• When working with large numbers, consider using a library that provides optimized BigNumber implementations, such as Decimal.js or BNP.js.

• Always validate user input to avoid unexpected errors.

• Keep your contract logic separate from the library used for number handling. This will make it easier to switch between libraries if necessary.

Conclusion

If you understand the BigNumber overflow problem when using Metamask on Ethereum, you can take steps to avoid this problem and ensure the success of your smart contracts. By exploring alternative libraries like Decimal.js or BNP.js, you’ll be able to write more efficient and reliable code that handles large numbers with ease.

Additional Resources

If you’re interested in learning more about BigNumber.js and other number handling libraries, here are some additional resources:

• [BigNumber.js Documentation](

• [Decimal.js Documentation](

• [BNP.js Documentation](