Free online query string to JSON converter. Parse URL parameters into a JSON object. Auto-detects JSON-encoded values within parameters. Runs locally in your browser.
100% Local
How to Use the Query String to JSON
Paste a URL query string into the input box (with or without a leading ?). Click Convert to JSON and each parameter becomes a key-value pair in a JSON object. Use Clear to reset.
How values are parsed
Each parameter becomes a key in the output object
Values that are valid JSON are auto-parsed (numbers, booleans, objects)
Non-JSON values are kept as plain strings
URL-encoded characters are decoded correctly
Features
Uses the native URLSearchParams API for correct parsing
Smart value detection — auto-parses JSON values
Works with or without a leading question mark
All processing runs locally in your browser. Your data is not uploaded to any server.