What makes an airdrop free?
A campaign is usually called free when it does not require buying a token. Some still require gas fees, social verification, testnet activity, or product usage, so users should treat time and transaction costs as part of the decision.
Where to look first
Start with official project docs, verified social channels, ecosystem quest boards, and reputable community trackers. Avoid random claim pages that are not linked from the project itself.
How to reduce risk
Use a dedicated wallet, avoid high-value holdings, revoke risky approvals, and never share seed phrases. The best free crypto airdrop is still not worth compromising wallet security.