Convert JSON to a URL Query String
Paste a JSON object of key/value pairs to build a URL query string. Keys and values are percent-encoded, and array values expand into repeated keys.
Object in, query string out
Give it a flat JSON object. Each key/value pair becomes key=value, joined with &. Both sides are percent-encoded, so spaces become %20 and reserved characters like & inside a value are escaped so they do not break the string.
Arrays
An array value expands into repeated keys: {"tag":["a","b"]} becomes tag=a&tag=b. This is the most widely understood convention and round-trips with the query-string-to-JSON tool.
Nested objects
A nested object or array-of-objects value is serialized to compact JSON before encoding. Query strings are meant for flat data, so flatten deep structures first if the receiver expects individual parameters.
FAQ
Is there a leading question mark?
No. The output is just the query portion so you can append it after your own path and ?. Add the ? yourself.
How are booleans and numbers handled?
They are converted to their text form — true, false, 36 — then encoded. The receiver reads them back as strings.
Will it round-trip?
Flat objects and arrays round-trip cleanly with the reverse tool. Nested objects come back as JSON strings, not re-parsed structures.