Query String Parser

Turn query strings into key/value tables and JSON into query strings.

How to use the Query String Parser

1. Query → JSON: paste a URL or query string to see every parameter decoded, and the same data as JSON.
2. JSON → Query: paste a JSON object to get the query string, choosing how arrays are written.

Repeated keys and brackets

There's no single standard for lists and objects in query strings, so frameworks differ:

• size=42&size=43: repeated keys. Spring binds them to a List or array (@RequestParam List<Integer> size); most frameworks read them this way.
• tags[]=a&tags[]=b and filter[brand]=acme: bracket notation, used by PHP, Rails and Node's qs library for arrays and nested objects.
• size=42,43: comma-separated, which Spring also splits into a list for @RequestParam.

Frequently asked questions

Why is + turned into a space?

Query strings use form encoding, where + means a space. A literal plus sign is written %2B.

Is my URL uploaded?

No. Parsing happens in your browser.