Foundry vs Slither
A detailed head-to-head comparison of Foundry and Slither — pricing, features, and which one wins for different use cases.
Foundry
Blazing-fast Rust-based Solidity testing framework with built-in fuzzing and invariant testing
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 ove…
Full review →Slither
Trail of Bits' open-source static analysis framework for Solidity — catches vulnerabilities before auditors do
Slither is the most widely used static analysis framework for Solidity smart contracts, built and maintained by Trail of Bits — one of the most respected security firms in the industry. It analyzes So…
Full review →Feature Comparison
| Feature | Foundry | Slither |
|---|---|---|
| Local Node | ✓ | ✗ |
| Mainnet Forking | ✓ | — |
| Language | Solidity (tests) | Solidity |
| Test Framework | forge-std | N/A (analysis tool) |
| Plugin Ecosystem | Growing (smaller than Hardhat) | slitherin + custom detectors |
| Debugging | ✓ | ✗ |
| Deployment System | Forge scripts | N/A |
| Open Source | ✓ | ✓ |
| Fuzz Testing | ✓ | ✗ |
| Invariant Testing | ✓ | — |
| Static Analysis | — | ✓ |
| Ci Cd Ready | — | ✓ |
Foundry Pricing
Foundry
Free (Open Source)
Free
- ✓forge, cast, anvil, chisel
- ✓Solidity tests
- ✓Built-in fuzzer
- ✓Invariant testing
- ✓Mainnet forking
- ✓Forge Standard Library
Slither Pricing
Slither
Free (Open Source)
Free
- ✓80+ vulnerability detectors
- ✓Custom detector support
- ✓CI/CD integration
- ✓Printer modules
- ✓Slitherin plugin ecosystem
Verdict: Which Should You Choose?
Foundry is the better pick if you need 5–20x faster test execution than hardhat — critical for large suites and audit pipelines. Slither wins when 80+ vulnerability detectors catch reentrancy, access control, and overflow issues before deployment. Both are production-ready — the right choice depends on your team's workflow and budget.