Exploit a smart contract. In your browser.

Inspect vulnerable Solidity, write the exploit, and run it against a live checker.

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Complete hacking challenges and level up

  1. 01 Fallback
  2. 02 Fallout
  3. 03 Coin Flip
  4. 04 Telephone
  5. 05 Token
  6. 06 Delegation
  7. 07 Force
  8. 08 Vault
  9. 09 King
  10. 10 Re-entrancy
  11. 11 Hostile Takeover
  12. 12 Elevator
  13. 13 Privacy
  14. 14 Gatekeeper One

CTF Library

7 CTFs shown

Smart contract CTF FAQ

What is a smart contract CTF?

A smart contract CTF is a security challenge where you exploit intentionally vulnerable blockchain contracts. These challenges help developers and auditors practice bugs such as reentrancy, access control failures, oracle manipulation, and broken accounting logic.

What are the best smart contract CTFs for beginners?

Ethernaut and Capture the Ether are good beginner-friendly options because they use smaller challenges that introduce common Ethereum and Solidity security concepts before moving into DeFi complexity.

Which smart contract CTF is best for DeFi security?

Damn Vulnerable DeFi is a strong DeFi-focused practice resource. It covers scenarios involving flash loans, lending, governance, oracles, AMMs, and token mechanics.

Are smart contract CTFs enough to become an auditor?

No. CTFs are useful for exploit practice, but real audits also require code review discipline, threat modeling, protocol understanding, invariant thinking, reporting skills, and familiarity with production codebases.

Should I read CTF writeups while solving?

Use writeups after a serious attempt. Reading too early can make the challenge feel clear without building the debugging and reasoning skills needed for real audits.