Storage Packing Optimizer Suggester

WHAT IT DOES

Storage Packing Optimizer Suggester is a read-only developer tool that analyzes EVM smart contract storage layouts and generates optimization recommendations to reduce gas costs and improve storage efficiency. It examines contract bytecode to detect storage variable patterns, simulates slot assignments, identifies inefficient variable ordering, and quantifies storage wastage in bytes. The tool provides actionable suggestions including variable reordering to pack smaller types together, converting multiple boolean flags into bitmaps, and reducing integer sizes where feasible. It visualizes the current storage layout with slot-by-slot breakdowns and estimates potential gas savings, helping developers optimize contract deployment costs and reduce transaction fees for users.

HOW TO USE

Connect your EVM-compatible wallet via the BGWallet bridge and select the network where your contract is deployed. Enter the contract address and click "Suggest Storage Optimizations". The tool fetches the bytecode, analyzes storage patterns using opcode detection (SLOAD/SSTORE operations), simulates a storage layout based on variable signatures, and generates optimization suggestions. Results include a detailed storage layout visualization showing each variable's slot and offset, a storage efficiency percentage, estimated wastage in bytes, and prioritized recommendations with severity levels. All analysis is read-only—no signatures or transactions are submitted.

TECHNICAL MECHANISM

The tool uses ethers.js v5.7.2 to fetch contract bytecode via provider.getCode(address), then performs static analysis to detect storage-related operations. It scans for SLOAD (0x54) and SSTORE (0x55) opcodes to confirm the contract uses storage, then simulates a storage layout using heuristic pattern detection from bytecode signatures and variable naming conventions extracted from function signatures. Variables are assigned types based on common patterns—address, uint256, uint128, uint64, uint32, uint16, uint8, bool, bytes32, and dynamic types like mapping and string. The tool simulates Solidity's storage packing rules: variables smaller than 32 bytes are packed into the same slot when possible, starting from offset 0; if a variable doesn't fit in the current slot, it starts a new slot; dynamic types always occupy a full 32-byte slot. The tool calculates storage efficiency as the ratio of used bytes to total allocated bytes across slots, identifies wasted space (gaps between packed variables), and generates optimization suggestions based on detected inefficiencies. Suggestions include reordering variables to improve packing (e.g., grouping bools and uint8s together), converting multiple booleans to a uint256 bitmap to save slots, and reducing uint256 sizes to smaller integers where values allow. Each suggestion is categorized by severity (high/medium/low) with actionable implementation details.

WHAT IT CANNOT SEE

This tool has fundamental limitations that users must understand. It cannot automatically reorder variables across inheritance boundaries or detect dependencies between variables that prevent reordering—contracts with inherited storage from base contracts require careful manual analysis to avoid breaking storage layout. It cannot guarantee that suggested packing optimizations are safe without manual review of code semantics and assembly blocks—inline assembly can directly access storage slots in ways that Solidity's automatic packing does not capture. It cannot detect storage collisions or ambiguous slot assignments in unverified contracts where storage layout cannot be determined with certainty—without source code verification, the tool uses heuristics that may produce false positives or miss optimizations. It cannot account for upgradeable proxy patterns where storage layout cannot be changed after deployment—optimizations requiring variable reordering would break proxy storage schemas. It cannot detect variables that are intentionally left unpacked for gas optimization reasons (e.g., to avoid frequent SLOAD/SSTORE operations on packed slots). It cannot assess the impact of changes on contract size, compilation time, or code readability. The tool's suggestions are based on simulated layouts and should be validated against actual source code.

PLEASE NOTE

This tool only supports EVM-compatible blockchains (Ethereum, Polygon, BSC, Avalanche C-Chain, Optimism, Arbitrum, and their testnets). Solana, Tron, Starknet, SUI, TON, Aptos, Bitcoin, Cosmos, and XRP are not supported. The tool is free, open-source, requires no API keys, and uses the wallet's native provider for all read operations. Always test storage optimizations in a development environment before deploying to production, as storage layout changes can break contract functionality if not handled correctly.