Generate API keys with custom prefix (sk_live_, pat_, lsk_), length, and character set. Shows entropy in bits. Get Go, TypeScript, and Python generation code. Inspired by Stripe (sk_live_) and OpenAI (sk-) formats.
Free, no sign-up — one of the SaaSQuickStart Developer tools.
Prefixes make keys self-documenting and help secret scanners (GitHub, GitLeaks) detect leaked keys. Stripe, OpenAI, and Anthropic all use prefixes. They also let you distinguish test keys from live keys at a glance.
32 characters of alphanumeric (62 chars) gives ~190 bits of entropy — far beyond brute-forceable. 24 characters (143 bits) is fine for most use cases. Never go below 16 characters (95 bits).
Yes — store SHA-256(key) in your database, not the raw key. Show the raw key to the user exactly once on creation. This way a database leak doesn't expose working keys. Stripe and GitHub both do this.
Base58 removes visually ambiguous characters (0, O, I, l) that users might confuse when copying by hand. Use it if users will ever manually type or transcribe keys. For machine-to-machine use, alphanumeric is simpler and has slightly higher entropy.