Understanding JSON in URL Query Strings, Base64URL Payloads, & Structural Analysis
RESTful APIs, GraphQL clients, and stateful web applications often pass structured JSON objects inside HTTP GET query parameters (e.g. ?filter=%7B%22status%22%3A%22active%22%7D). To transport JSON securely in a URI, reserved characters such as {, }, ", and : must be percent-encoded per RFC 3986.
Base64 & Base64URL Query Parameter Encoding
To avoid long percent-encoded sequences, modern API gateways encode JSON payloads into Base64 or URL-safe Base64URL strings (RFC 7515). Base64URL replaces + with - and / with _ without padding. Our decoder automatically detects Base64URL patterns and decodes them safely into formatted JSON.
Interactive Collapsible JSON Tree Viewer & Structural Metrics
Inspecting complex JSON structures is effortless with our interactive JSON tree view. Expand or collapse nested objects/arrays, filter keys using real-time search, convert payloads into clean YAML, and analyze AST node counts and nesting depth.
100% Local Browser Privacy & Security
Query strings and JSON payloads often contain user filters, session tokens, or API credentials. Our JSON URL Decoder runs 100% locally in your web browser using JavaScript Web Workers. Zero payloads or data leave your machine.