JSON Flatten & Unflatten

Collapse a nested JSON object into dot-path key/value pairs ({"a":{"b":1}} → {"a.b":1}), or expand a flat dot-path object back into its nested form. Handles arrays with numeric indices, escapes literal dots in keys, and preserves JSON value types (string, number, boolean, null). The reverse of the JSON Pointer tool's addressing scheme — useful for spreadsheets, env-file generation, and diffing nested structures. Everything runs locally in your browser.