Query String ↔ JSON Converter

Convert URL query strings and JSON objects bidirectionally.

Category: Converters

When to use?

Use it to expand a URL query string into a JSON object to inspect parameters, or to convert a JSON object into URLSearchParams form to build an API request URL.

How to use

  • Choose the direction (Query String → JSON or JSON → Query String).
  • Enter the data.
  • Copy the result.

Input Explanation

Enter the query string from a URL (e.g. ?id=1&name=abc) or a JSON object to turn into parameters.

Calculation Basis

It uses the URLSearchParams API to decode/encode key=value& patterns into objects, applying decodeURIComponent and encodeURIComponent to safely handle special characters.

Usage Examples

  • Inspect API parameters - Expand a URL query string into a JSON object to inspect.
  • Build test URLs - Convert a JSON object into a URLSearchParams query string.
  • Debug parameters - Expand a complex query string into JSON to see the values.

Examples

  • "name=John&age=30" → {"name":"John","age":"30"}
  • {"name":"John","age":30} → "name=John&age=30"

Cautions

  • Malformed source data can cause parsing errors or broken output.
  • A mismatched encoding standard or complex nested data may break or drop the structure.

Guides

Query string structure

A query string is key=value pairs joined by & after the ? in a URL. Repeated keys can be treated like an array.

Check URL encoding

Non-ASCII characters, spaces, and special characters need URL encoding. For values that look broken, check with the URL encode/decode tool.

FAQ

How are repeated keys handled?

When the same key appears several times, it is preserved as a JSON array.

Are non-ASCII characters encoded?

For JSON → Query String, they are auto-encoded per URLSearchParams.

Can I paste a full URL starting with ?

It recognizes the query string part after ? in the URL and converts it.

Are keys with no value handled?

Yes. A key with an empty value converts to an empty string.

Related Tools

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  • YAML ↔ JSON Converter - Convert YAML and JSON data bidirectionally in the browser.
  • URL Encode / Decode - Encode text into URL-safe form (%XX) or decode an encoded URL back to text.
  • JSONPath Tester - Extract values from JSON data using a JSONPath expression.
  • Base64 Converter - Encode text to Base64 or decode a Base64 string back to text.
  • HTML Escape / Unescape - Convert HTML special characters to entities, and restore entity strings back to characters.