Build auth headers: Bearer token, Basic auth, API key. OAuth and custom.
API Authentication Builder: Build auth headers: Bearer token, Basic auth, API key. OAuth and custom. Use when you need realistic sample data for prototypes, demos, or integration tests. No server interaction after page load. Your data is never logged, stored, or transmitted. A free API Tools tool on HttpStatus.com — no installation needed.
Yes — each generation produces fresh values. Where applicable, cryptographic randomness ensures uniqueness.
Many tools support shareable links. Look for the share button after processing your input.
Client-side tools use your device's memory, so they handle up to several megabytes. Very large inputs may slow the tab.