Query String Builder
Parse query strings from URLs or build them from JSON key/value pairs.
About this tool
Parse query strings from URLs or build them from JSON key/value pairs. Turn opaque strings from network traces, devtools, or SEO audits into structured output you can act on.
Choose Parse to turn a query string or full URL into a JSON map of params. Choose Build to turn a JSON object (arrays allowed) into an encoded query string. Example — Parse a search URL: try `https://example.com/search?q=hello&tag=js&tag=ts` and expect something like `{ "q": "hello", "tag": ["js", "ts"] }`.
Nested objects are stringified as JSON values — not expanded into bracket notation. See also: URL Parser, URL Encoder/Decoder, and JSON Formatter. Runs in your browser — nothing you paste gets uploaded.
How to use
- Choose Parse to turn a query string or full URL into a JSON map of params.
- Choose Build to turn a JSON object (arrays allowed) into an encoded query string.
- Run and copy the Output into clients, docs, or curl snippets.
- Re-encode individual values with URL Encode/Decode when you need partial escapes.
Example
Parse a search URL
Input
https://example.com/search?q=hello&tag=js&tag=ts
Output
{
"q": "hello",
"tag": ["js", "ts"]
}Limitations
- Nested objects are stringified as JSON values — not expanded into bracket notation.
- Hash fragments are ignored when parsing full URLs.
- Does not validate business rules for required params — only encode/decode structure.
Related guides
1Related tools
3Frequently asked questions
What does the Query String Builder do?
Parse query strings from URLs or build them from JSON key/value pairs. Runs in your browser — no install, no account.
How do I use the Query String Builder?
Choose Parse to turn a query string or full URL into a JSON map of params. Choose Build to turn a JSON object (arrays allowed) into an encoded query string. Run and copy the Output into clients, docs, or curl snippets. Re-encode individual values with URL Encode/Decode when you need partial escapes.
Is the Query String Builder free?
Yes. No signup, no usage limits, no paywall.
Does the Query String Builder upload my data?
No. Processing happens locally in JavaScript. Your input is not uploaded, stored, or logged.
What are the limitations of the Query String Builder?
Nested objects are stringified as JSON values — not expanded into bracket notation. Hash fragments are ignored when parsing full URLs. Does not validate business rules for required params — only encode/decode structure.