Ideas for preventing free tier abuse?

Hey everyone,

I’m running into an issue with my API-based product, brand.dev.

Too many people are abusing the free tier—creating multiple accounts and rotating API keys to get around limits. Including some bigger companies.... :I

I’m considering shutting down open access to the free tier and requiring users to submit a request instead.

Has anyone dealt with this before? Any better approaches to prevent abuse while keeping things accessible for legitimate users?