API Key Checker

Paste a key. The page guesses which provider issued it, then verifies Anthropic keys against the live API.

Anthropic key formats

Regular API key: sk-ant-api03- followed by about 95 letters, digits, - and _. Total length is roughly 108 characters.
Admin API key: sk-ant-admin01- prefix. Manages the organization, cannot call the Messages API.
Both come from console.anthropic.com → API Keys.