Solidity Gas Optimizer

Analyze and optimize gas consumption in Solidity smart contracts using proven patterns and best practices.

When to Use This Skill

Use this skill when the user:

• Wants to reduce gas costs of their smart contract deployments or function calls
• Asks about gas-efficient coding patterns in Solidity
• Needs to compare gas usage between different implementation approaches
• Is preparing a contract for mainnet deployment and wants to minimize transaction costs

Optimization Categories

1. Storage Optimization

• Variable packing: Pack multiple variables into a single 256-bit storage slot
• Use bytes32 over string when possible for fixed-length data
• Avoid redundant storage reads: Cache storage variables in memory within functions
• Use mappings over arrays for lookups to avoid iteration

2. Function-Level Optimization

• Use calldata instead of memory for read-only function parameters
• Short-circuit evaluation: Place cheaper conditions first in require chains
• Batch operations: Combine multiple state changes into single transactions
• Use unchecked blocks for arithmetic that cannot overflow (Solidity 0.8+)

3. Deployment Optimization

• Use immutable and constant for values set once at deploy time
• Minimize contract size: Remove unused code, use libraries for shared logic
• Use proxy patterns for upgradeable contracts with shared logic

4. Loop Optimization

• Cache array length outside the loop: uint256 len = arr.length
• Use ++i instead of i++ to save ~5 gas per iteration
• Avoid unbounded loops: Always have a known upper bound

Example Usage

// Before: ~45,000 gas
function sum(uint256[] memory values) public pure returns (uint256 total) {
    for (uint256 i = 0; i < values.length; i++) {
        total += values[i];
    }
}

// After: ~38,000 gas
function sum(uint256[] calldata values) public pure returns (uint256 total) {
    uint256 len = values.length;
    for (uint256 i; i < len; ) {
        unchecked {
            total += values[i];
            ++i;
        }
    }
}

Tools & References

• Remix IDE - Gas estimation during development
• Foundry Gas Reports - Automated gas snapshots
• EVM Codes - Opcode gas cost reference