#070 · Developer Utilities Developer Tool

Query String Parser

Parse query strings without losing duplicate keys, empty values, key-only parameters, or invalid percent-encoded input.

Developer Input

Query string or full URL

Parameter Table

Duplicates preserved
KeyValue

How to use this developer tool

  1. Paste a query string or full URL.
  2. Select grouped JSON, ordered pairs, code, or rebuilt output.
  3. Choose ordering and empty-value behavior.
  4. Review duplicates in the table and copy the output.

What this developer tool does

Splits each parameter at the first equals sign, decodes values independently, and groups duplicate keys into arrays.

Extract query → split on & → split each pair at first = → decode safely → preserve duplicates → generate selected output.

Invalid percent encoding is preserved instead of stopping the entire conversion.

Example

tag=css&tag=html&user[name]=John&empty=&debug

Tips for better output

  • Use ordered pairs when parameter order is significant.
  • Use grouped JSON for application logic.
  • Keep raw input when debugging invalid encoding.

FAQ

How do I convert a query string into JSON?

Select Grouped JSON and run the parser.

How do I preserve duplicate query parameters as arrays?

Duplicate keys are automatically grouped into arrays in grouped JSON output.

How do I parse bracket notation in URL query strings?

Bracketed keys are preserved exactly, such as user[name].

How do I decode plus signs and percent-encoded query values?

Enable Convert + to space; percent encoding is decoded per key and value.

How do I rebuild a query string after editing parameters?

Select Rebuilt query string to generate an encoded query from the parsed rows.

Supported formats and output

Raw query strings, leading-question-mark strings, and full HTTP(S) URLs. Output is JSON, JavaScript, or rebuilt query text.