JSON to Query String Converter
Convert JSON objects to URL query strings with support for arrays, nested objects, and custom formatting options. Perfect for API requests, URL parameters, and form data encoding.
Conversion Options
Recommended Settings
Query String Best Practices
- •Always URL-encode values to handle special characters safely
- •Use brackets format (arr[]=1) for maximum server compatibility
- •Keep query strings under 2048 characters for browser compatibility
- •Skip null values in production to reduce URL length
- •Sort keys alphabetically for consistent caching
Format Selection Guide
- •Brackets (arr[]=1): Best for PHP, Ruby on Rails, most APIs
- •Repeat (arr=1&arr=2): Node.js/Express default, simple and universal
- •Indices (arr[0]=1): When order preservation is critical
- •Comma (arr=1,2): Most compact, check server support first
- •Bracket notation for nested objects is most widely supported
Pro Tips
- •Query strings are visible in URLs - never include sensitive data
- •This tool processes everything client-side for privacy
- •Encoded characters are automatically handled by encodeURIComponent
- •Some servers limit query string length - check your API docs
Most Popular
Brackets format with URL encoding enabled for maximum compatibility
When to Use This Tool
Building query strings for REST API calls with filters, pagination, and sorting parameters. Perfect for constructing GET requests with complex filtering criteria and multiple parameters.
Converting form data to application/x-www-form-urlencoded format for HTTP POST requests. Automatically handles arrays and nested objects according to server requirements.
Creating URLs with complex parameters for sharing, bookmarking, or deep linking. Ideal for building shareable links with state preservation and configuration parameters.
Encoding search queries with multiple filters, categories, and refinement options. Handles complex filter combinations while maintaining URL readability.
Building UTM parameters and tracking codes for marketing campaigns and analytics. Ensures proper encoding of campaign names, sources, and custom parameters.
Creating redirect URIs with state parameters and authorization codes. Properly encodes callback URLs and maintains authentication flow parameters.
How It Works
Parse and validate JSON input
Traverse object properties recursively
Format arrays based on selected style
Flatten nested objects with notation
URL-encode values for safety
Join pairs with ampersands
100% Private
Files never leave your device. All processing happens locally in your browser.
Lightning Fast
Powered by Pure JavaScript for optimal performance on modern browsers.
Secure
No data collection, no tracking, no sign-up required.
Frequently Asked Questions
Which array format should I use?
Brackets (arr[]=1) is the most widely supported format, used by PHP, Ruby on Rails, and many APIs. Use 'repeat' (arr=1&arr=2) for Node.js/Express. Use 'comma' (arr=1,2,3) for compact URLs when the server supports it. Use 'indices' (arr[0]=1) when order preservation is critical.
What's the difference between bracket and dot notation for nested objects?
Bracket notation (user[name]=John&user[email]=test@example.com) is more common and works with property names containing special characters. Dot notation (user.name=John) is cleaner and more readable but can't handle dots in property names. Both are supported by most modern frameworks.
Should I enable 'Encode values'?
Yes, in most cases. URL encoding ensures special characters like spaces, @, #, &, and = are properly escaped for safe transmission in URLs. Only disable if you're handling encoding separately or working with pre-encoded data.
How are null and undefined values handled?
By default, null values are converted to empty strings (key=). Enable 'Skip null values' to omit them entirely from the query string. Undefined values are always skipped.
Can I convert query strings back to JSON?
While this tool focuses on JSON to query string conversion, you can parse query strings to objects using URLSearchParams API in JavaScript or libraries like 'qs'. Note that some information (like type distinctions between numbers and strings) may be lost.
What's the maximum nesting depth supported?
The tool can handle deeply nested objects, but most servers have query string length limits (typically 2048-8192 characters). For very complex data structures, consider using JSON in the request body instead of query parameters.
How do I include the query string in a URL?
Append the generated query string to your URL with a question mark: https://api.example.com/search?name=John&age=30. If the URL already has a query string, use & to append more parameters.
Are there security considerations?
Query strings are visible in URLs, browser history, and server logs. Never include sensitive data like passwords, API keys, or personal information in query parameters. Use POST requests with body data for sensitive information. Always validate and sanitize query parameters on the server side.