Foundry Review (2026)

What is Foundry?

Foundry is a Rust-based Ethereum development toolkit built by Paradigm that has become the preferred framework for security-conscious and performance-focused Solidity teams. Its defining advantage over Hardhat is speed: test execution in Rust is typically 5–20x faster than JavaScript, which becomes critical for large test suites that would otherwise take minutes. Tests are written in Solidity itself — not JavaScript — which eliminates the context-switching overhead of maintaining both Solidity business logic and JavaScript test logic. Forge is the core test runner; Cast is a CLI for interacting with any EVM chain; Anvil is a local node similar to Hardhat Network; and Chisel is a Solidity REPL for interactive exploration. The built-in fuzzer automatically generates thousands of test inputs to find edge cases in numerical computations — catching bugs that hand-written test cases miss. Foundry's invariant testing framework runs stateful fuzzing across entire protocol interaction sequences, a technique used by professional auditors. Script-based deployments (Solidity scripts run via `forge script`) replace JSON deployment configs. The Forge Standard Library (forge-std) provides common test helpers, assertions, and cheatcodes. For teams writing new protocols or running competitive audits where coverage and speed matter, Foundry is the correct choice.

Foundry Pros & Cons

Foundry Pricing (2026)

Foundry offers a free plan.

Foundry Features

Frequently Asked Questions