DevCoreTools

Query Params to JSON Converter

Paste a query string or URL and convert its query parameters into clean JSON.

Query input

Paste a full URL, relative URL with a query string, or raw query parameters.

Processed locally in your browser Limit query text. Your input is processed in your browser and is not uploaded or sent to a server. Avoid pasting production secrets, access tokens, private keys, passwords, or sensitive customer data unless you understand the risk.
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JSON output

Formatted JSON object with decoded keys, values, duplicate arrays, and warnings.

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Converted JSON appears here.

Paste query parameters or load a sample to produce a formatted JSON object without opening or fetching any URL.

Query string to JSON guide

Convert query parameters into a structured JSON object for debugging redirects, API requests, tracking links, filters, and copied URLs.

Query strings as structured data

A query string is the part after ? in a URL. This converter focuses on those key-value pairs and outputs a JSON object you can inspect, copy, or save.

Repeated parameters

Repeated keys such as filter=color&filter=size are common in search filters. Preserve duplicates as arrays when every selected value matters.

Percent decoding

Encoded values like query%20params and plus signs are decoded for readability. Malformed percent escapes are kept as text and reported as warnings.

Empty values and missing equals

Both empty= and flag are preserved as empty strings so feature flags, blank filters, and intentionally empty parameters stay visible.

URL Parser vs this converter

URL Parser inspects the full URL structure. Query Params to JSON ignores protocol, host, path, and fragment details so the query object stays the main result.

Secret-like parameters

Names that look like tokens, API keys, sessions, or auth codes are flagged. Output is preserved by default, with an option to redact those values before copying.

Keep working

View all encoding tools
URL Parser / Query String ParserParse full URLs, relative URLs, and query strings into structured parts.JSON to Query String ConverterConvert JSON objects into URL query strings locally.JSON FormatterJSON ToolsFormat, validate, inspect, and export JSON locally.JSON ValidatorJSON ToolsValidate JSON syntax with clear messages, hints, and formatted output.JSON Escape / UnescapeJSON ToolsEscape and unescape JSON string literals locally.HTTP Headers Parser / FormatterAPI & Auth ToolsParse, format, inspect, and export HTTP headers locally with structured warnings.

Coming soon

URL Encoder/DecoderComing soonEncode and decode URL components and query-string values.

FAQ

Does this converter open or fetch URLs?

No. It treats everything as text and does not open links, call URLs, resolve DNS, or validate whether a URL exists.

Can I paste a full URL?

Yes. Paste an absolute URL or a relative URL with a query string. The converter extracts only the query parameters.

How are duplicate query keys handled?

By default, repeated keys become arrays. Turn off array preservation if you want the last value for a duplicate key to win.

What happens to parameters without values?

A key without an equals sign and a key with an empty value both become an empty string in JSON so the key is not lost.

Should I use this or URL Parser?

Use this tool when you need JSON from query parameters. Use URL Parser when you need protocol, host, path, fragment, credentials, and a broader URL report.