Gas Snapshot Comparison Tool Between Test Runs

WHAT IT DOES

This tool connects to your EVM wallet and compares gas snapshots from different test runs, helping you track gas cost changes across contract versions. It reads gas snapshot data including deployment costs, individual function gas usage, and transaction costs from test run outputs. The tool displays side-by-side comparisons of gas costs, calculates differences, and highlights regressions or improvements, enabling developers to monitor the gas efficiency impact of code changes.

HOW TO USE

Connect your Web3 wallet using the Connect button. In the Snapshot A field, paste gas snapshot data from a previous test run. In the Snapshot B field, paste gas snapshot data from a newer test run. Gas snapshot data should be in JSON format with deployment and functions fields. For example, {"deployment":450000,"functions":{"setValue":45000,"getValue":22000}}. Click "Compare Snapshots" to generate a detailed comparison. Click "Load Sample Data" to populate fields with example snapshots. Results appear in the Results card with summary metrics and a function-by-function comparison table showing gas cost differences.

TECHNICAL MECHANISM: GAS SNAPSHOT PARSING AND DIFFERENTIAL ANALYSIS

The tool parses two JSON snapshot objects containing deployment gas costs and per-function gas costs. It iterates through all function names present in either snapshot, calculating the gas cost difference for each function as: snapshotB - snapshotA. Total gas costs are calculated by summing deployment costs and all function costs. The tool displays deployment costs, total costs, and per-function differences with color coding—red for increases, green for decreases. A summary tag indicates overall trend with arrows and numeric differences. The comparison table is rendered dynamically using DOM elements for a clean, readable presentation.

WHAT IT CANNOT SEE

This tool cannot execute test runs or generate gas snapshots itself—it relies entirely on externally provided snapshot data. It cannot predict gas costs on different chains or at different times—gas costs vary by network and network conditions. It cannot account for gas price fluctuations or network conditions—the tool only compares static gas usage values. It relies on external test frameworks and gas reporting tools—the tool is not a gas estimator. It cannot compare snapshots from different contract versions without manual input—the tool requires both snapshots to be provided.

PLEASE NOTE

This is a read-only tool—it never signs transactions. All data is processed in-memory and never persists. The tool supports EVM chains only—Ethereum, Polygon, BSC, Arbitrum, Optimism, Avalanche, Base, and Fantom. Gas snapshots must be provided in the specified JSON format. The tool does not replace proper gas profiling tools like Hardhat Gas Reporter or Foundry gas snapshots—use dedicated tooling for accurate gas measurement. Comparisons are only as accurate as the snapshot data provided.