Query String to JSON
Convert a URL query string into a JSON object. Repeated keys (?tag=a&tag=b) become arrays, the leading ? or # is optional, and percent-encoded characters are decoded — all in your browser.
Query String in, JSON out
A small sample to show the shape of the conversion. Pretty-printed output, types preserved where possible.
?page=1&tag=a&tag=b
{
"page": "1",
"tag": ["a", "b"]
}What you'll use this for
Query String to JSON shows up in every backend and ETL stack — feeding APIs, migrating configs, debugging payloads.
API & data imports
Prepare payloads for REST APIs and ingestion endpoints.
Data migration
Move configuration and tabular data between systems and formats.
Debugging
Inspect production data in a sensible, structured form.
ETL pipelines
Stage transformations between formats in your data flow.
How to convert Query String to JSON
Paste your Query String
Drop your source into the left editor. The sample loads on first visit — replace it with your data.
Click Convert
Or leave Auto-convert on for live updates as you type. Conversion runs locally.
Review the output
The right pane shows pretty-printed JSON with status, byte counts, and line count.
Copy or download
Use the action bar to copy to clipboard or save as a file. Or jump to the reverse converter for round-trip checks.
Frequently asked questions
No. ? or # at the start is stripped automatically. a=1&b=2 works just as well as ?a=1&b=2.
Multiple values for the same key (?tag=a&tag=b) become a JSON array.
Yes — values are URI-decoded via URLSearchParams, so %20 becomes a space, %2F becomes /, etc.
Keys like tag[] are kept as-is (not parsed into arrays via brackets). Use repeated keys for arrays.
Yes. The browser does the parsing, nothing is uploaded.
About Query String to JSON
Query strings are the trailing part of a URL after ?: a set of key=value pairs separated by &. They carry pagination, filters, and tokens. Converting to JSON makes them easy to log, transform, or send to an API.
How parsing works
- Leading
?or#is stripped. - Browser's
URLSearchParamshandles percent-decoding and+as space. - Duplicate keys collapse to an array.
Use cases
- Debug API request URLs.
- Snapshot filter state from a SPA.
- Generate JSON payloads from existing URLs.