A head-to-head comparison of Hardhat and Foundry — pricing, the features that actually differ, and which one fits which use case.
The most widely used Ethereum development environment with a robust plugin ecosystem
Blazing-fast Rust-based Solidity testing framework with built-in fuzzing and invariant testing
These are the 6 capabilities where the two tools genuinely diverge — the rest of their feature sets overlap.
| Capability | Hardhat | Foundry |
|---|---|---|
| Language | JavaScript / TypeScript | Solidity (tests) |
| Test Framework | Mocha + Chai | forge-std |
| Plugin Ecosystem | 90+ plugins | Growing (smaller than Hardhat) |
| Deployment System | Hardhat Ignition | Forge scripts |
| Coverage Reporting | Yes | — |
| Gas Reporting | Yes | — |
| Feature | Hardhat | Foundry |
|---|---|---|
| Local Node | ✓ | ✓ |
| Mainnet Forking | ✓ | ✓ |
| Language | JavaScript / TypeScript | Solidity (tests) |
| Test Framework | Mocha + Chai | forge-std |
| Plugin Ecosystem | 90+ plugins | Growing (smaller than Hardhat) |
| Debugging | ✓ | ✓ |
| Deployment System | Hardhat Ignition | Forge scripts |
| Open Source | ✓ | ✓ |
| Coverage Reporting | ✓ | — |
| Gas Reporting | ✓ | — |
| Fuzz Testing | — | ✓ |
| Invariant Testing | — | ✓ |
Both tools are free to use — costs come from network or usage fees.
Hardhat
Free
Foundry
Free
Watch out: JavaScript-based test execution is 5–20x slower than Foundry for large test suites.
Watch out: Smaller plugin ecosystem than Hardhat — some tooling requires custom solutions.
Foundry edges ahead on our editorial score (4.8/5), but these tools aren’t straight substitutes. Pick Hardhat when largest plugin ecosystem — 90+ community plugins cover every testing and tooling need matters most to your workflow; pick Foundry when 5–20x faster test execution than hardhat — critical for large suites and audit pipelines is the priority. The deciding factor is usually the trade-off you can least afford — Hardhat means accepting that javascript-based test execution is 5–20x slower than foundry for large test suites, while Foundry means smaller plugin ecosystem than hardhat — some tooling requires custom solutions.
Foundry carries the higher editorial rating (4.8/5 vs 4.7/5), but they solve different problems. Hardhat is the stronger pick when you need largest plugin ecosystem — 90+ community plugins cover every testing and tooling need. Foundry wins when 5–20x faster test execution than hardhat — critical for large suites and audit pipelines.
Both tools are free to use, with costs coming from network or usage fees rather than subscriptions.
Hardhat's main limitation is that javascript-based test execution is 5–20x slower than foundry for large test suites. For Foundry, smaller plugin ecosystem than hardhat — some tooling requires custom solutions. Weigh these against how you actually plan to use the tool.
In most cases yes — many teams run both, using each where it's strongest. Since Hardhat leads on largest plugin ecosystem — 90+ community plugins cover every testing and tooling need and Foundry on 5–20x faster test execution than hardhat — critical for large suites and audit pipelines, the two are often complementary rather than mutually exclusive.