Start with the trust question you need to answer
Why startups use World ID
- Stop bots and duplicate accounts. Make rewards, referrals, voting, reviews, promotions, and social participation one-person-one-action.
- Protect sensitive moments. Add human presence when someone approves a payment, recovers an account, deploys software, or authorizes a high-risk transaction.
- Check eligibility privately. Confirm that someone meets a policy without asking your product to store their full identity documents.
- Match trust to risk. Start with a lightweight check, then require stronger proof of humanity, presence, or eligibility where the stakes are higher.
- Build safer AI products. Distinguish people from agents and make human approval an explicit boundary for consequential actions.
- Make communities more accountable. Reduce impersonation, fake accounts, reputation manipulation, and fraudulent content while preserving privacy.
Where it fits in YC startups
Keep the first use case simple
Choose the one action where abuse would most change the outcome—such as creating an account, claiming a reward, receiving a referral benefit, voting, or accessing a scarce resource. Start there, then add stronger trust signals only when the risk calls for them.World ID helps you know that a unique human can participate. Use Selfie Check when you need a signal that someone is present now, Identity Attestations when you need to know whether they meet a requirement, and AgentKit when an agent needs to act on their behalf.