Comparison · Web3
Foundry vs Hardhat for Smart Contract Development
Foundry or Hardhat for Solidity development? Compare testing, speed, fuzzing, language, plugins and deployment for your next smart contract project.
The short answer
Foundry is excellent when you want fast tests written in Solidity with built-in fuzzing and invariant testing. Hardhat suits teams who prefer a JavaScript/TypeScript workflow and its plugin ecosystem. Many teams use both, for example Foundry for testing and Hardhat for scripts and integrations.
Side by side
| Feature | Foundry | Hardhat |
|---|---|---|
| Language for tests | Solidity | JavaScript/TypeScript (recent versions also support Solidity tests) |
| Speed | Very fast compilation and tests | Fast; depends on setup |
| Fuzz and invariant testing | Built in | Via plugins or newer built-in features |
| Local chain | Anvil | Hardhat Network |
| Ecosystem | Growing; cast and chisel tools | Large plugin ecosystem |
| Best fit | Security-focused Solidity teams | Full-stack JS/TS teams |
Updated October 2026. Products and prices change; check official sites for current details.
Which is best for you?
Foundry
You want rigorous, fast testing in the same language as your contracts.
Hardhat
Your team lives in TypeScript and relies on its plugins.
The framework isn't the security
Either works. What protects users is a clear spec, thorough tests (including fuzz and invariants), static analysis, review and an audit for significant value.
Where EmmaForYou fits
We write and test Solidity with Foundry and Hardhat, and prepare contracts for audits.
More comparisons
Good to know
Can I switch later?
Yes. Contracts are plain Solidity; it's mainly tests and scripts that change.