{
"a": "1",
"b": "two",
"list": [
"x",
"y"
]
}About Query String to JSON Converter – Parse URL Params
A URL query string is the part after the "?" — pairs like `?page=2&sort=name` that carry parameters into a request. They're compact for machines but awkward to read when you're debugging an API call, a redirect, or a tracking URL with a dozen params crammed together.
This free query string to JSON converter parses those params into clean, readable JSON — repeated keys collapse into arrays and every value is URL-decoded — and serializes JSON back into a valid query string. It runs entirely in your browser, so the URLs and tokens you paste never leave your device.
Features
- Parse URL params to JSON and serialize JSON back to a query string
- Repeated keys (a=1&a=2) become a JSON array
- Values URL-decoded on parse and re-encoded on serialize
- Tolerates a leading "?"; works completely offline
How to use
- Paste a query string (or JSON object) into the input pane.
- Choose "Query → JSON" to parse, or "JSON → Query" for the reverse.
- Read the converted result and copy it from the output pane.
Frequently asked questions
How are repeated keys handled?
When a key appears more than once — for example a=1&a=2 — the values are grouped into a JSON array: { "a": ["1", "2"] }. Serializing that JSON back produces the same repeated-key query string.
Are values URL-decoded?
Yes. On parse, percent-encoding and "+" are decoded, so b=two+words becomes "two words". On serialize, values are re-encoded so the output is a valid, safely-escaped query string.
Why are all the values strings?
A query string has no type information — every value is text. So a=1 parses to the string "1", not the number 1. When serializing JSON back, numbers and booleans are converted to their string form.
Does my data get sent anywhere?
No. Parsing and serializing happen locally in your browser using the built-in URLSearchParams API. The query strings, URLs, and tokens you paste never leave your device.
Related tools
Everything runs locally in your browser — your input is never uploaded.