What does this API key generator create?
It creates high-entropy, opaque strings suitable for authenticating requests to an API you own. Every key is generated from the browser’s cryptographically secure random-number source, and batch results are checked for uniqueness.
Choosing 128, 256, or 512 bits
For a newly designed API key, 256 random bits is a strong general default. The other sizes exist for systems with explicit format or compatibility requirements. A longer key does not repair insecure storage, accidental logging, excessive permissions, or missing revocation controls.
Base64URL, hexadecimal, or alphanumeric?
Base64URL is compact and avoids characters that need URL escaping. Hexadecimal is longer but widely accepted and easy to inspect. Alphanumeric output is useful for systems with restrictive character rules; this tool rounds its length up so the random portion meets or exceeds the selected entropy.
Prefixes and environments
A prefix such as api_test_ can help operators identify a credential’s role and find accidental exposure. It is not secret, is not included in the entropy calculation, and should not imitate a third-party provider’s proprietary credential format.
Store API keys safely
Display a newly issued key only once, transmit it over HTTPS, and store the server-side verifier securely. High-entropy keys can usually be stored as a cryptographic hash so a database leak does not reveal the original credential. Keep a separate identifier when efficient lookup is required, compare verifiers safely, restrict scope, and support expiration, rotation, and revocation.
API keys are not provider credentials or JWTs
A random string cannot become a valid key for an outside service. Provider credentials must be created in that provider’s own dashboard. A JWT is a structured, signed token rather than an opaque API key; use the JWT Secret Generator only for symmetric HMAC signing secrets.
Sources and technical basis
Random values come from the browser’s Web Crypto getRandomValues() API. Operational guidance follows the OWASP Secrets Management Cheat Sheet. Generation happens entirely on this page with no account or server request.
Related developer tools
PostgreSQL password generator creates strong login-role credentials and URI-encoded output. Random key generator creates unlabeled raw key material. Django secret key generator follows Django's framework-specific format. Random string generator creates customizable identifiers and test data. Use this page when you need one or more opaque API credentials with prefixes and environment-file output.