# Gas Saving Technique 7: Using Short Reason Strings

{% hint style="info" %}
[**Book an audit with Zokyo**](https://www.zokyo.io/)
{% endhint %}

#### Introduction

Developing cost-efficient smart contracts on the Ethereum blockchain requires a keen eye for detail, where even seemingly minor optimizations can lead to reduced gas consumption. One such optimization technique involves minimizing the length of reason strings used in `require` statements or error messages. Keeping reason strings short and concise not only aids in readability but also helps save gas, making transactions more cost-effective.

#### Impact & Details

**Understanding Gas Consumption**

* **Size Matters**: In Ethereum, the deployment and execution cost of smart contracts is influenced by their size. Since strings consume storage, longer reason strings naturally lead to higher gas costs. Every string used occupies at least 32 bytes.
* **Cost Efficiency with Short Strings**: By keeping reason strings within 32 bytes, you can avoid unnecessary gas expenses. Short, clear, and meaningful strings are the key to efficient gas usage and effective communication with contract users.

#### How to Implement Short Reason Strings for Gas Savings

**Practical Example: Efficient Reason Strings Usage**

Below are examples illustrating the optimization:

Before Optimization:

```solidity
solidityCopy code// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

contract ReasonStringsOptimizer {
    function doSomething(uint value) public pure {
        require(value > 10, "The provided value must be greater than 10");
    }
}
```

After Optimization:

```solidity
solidityCopy code// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

contract ReasonStringsOptimizer {
    function doSomething(uint value) public pure {
        require(value > 10, "Value must be > 10");
    }
}
```

In the optimized version, the reason string is shortened while still conveying the necessary information, thereby saving gas.

#### Recommended Mitigation Steps

1. **Identify Long Reason Strings**: Go through your smart contracts and identify reason strings that exceed 32 bytes.
2. **Shorten Reason Strings**: Redraft and shorten the identified strings, ensuring they remain within 32 bytes while still conveying the intended message clearly.
3. **Test**: Conduct testing to ensure the smart contract functions as expected with the revised reason strings, while also saving gas.

#### Conclusion

Employing short reason strings is a straightforward yet effective technique to save gas in smart contract development. While the gas savings for individual transactions might be small, the cumulative effect over numerous transactions can be substantial. Additionally, concise messages contribute to better readability and understanding of the contract’s functions and requirements. After implementing these changes, thorough testing is crucial to confirm that the contract continues to operate as intended while utilizing less gas.





