Ready State

Definitions

1. A property (readyState) on browser objects like XMLHttpRequest and Document that indicates the current phase of a lifecycle — for XHR: 0 (UNSENT) through 4 (DONE); for Document: "loading", "interactive", or "complete". Kubernetes also uses a ready state to indicate a pod can accept traffic, gated by readiness probes.

   In plain English: A status indicator that tells you what stage something is at — loading, partially loaded, or fully done and ready to use.

   Example: "The legacy code checks xhr.readyState === 4 && xhr.status === 200 before parsing the response — it predates fetch()."

Related Terms

• CORS
• CORS Preflight
• Fetch API
• Security Headers
• CORS Origin
• Rails Router
• Route Handler
• Session Storage
• User Agent
• Web Animation API
• Web Audio API
• Web Push
• Web Storage
• Window