Query String Parser
Parse, edit, validate and reorganize URL Query Parameters. Supports editable tables, JSON ↔ Query conversion, and URL Encode/Decode.
Suitable for API development, SEO, website analysis and debugging.
Query String Frequently Asked Questions FAQ
Q1: What is Query String?
Query String is in the URL ? The following part is used to pass parameters to the server. it consists of one or more key=value Composed, used between multiple parameters & Separate.
Example:
https://example.com/search?q=hello&page=2&sort=desc
where Query String is q=hello&page=2&sort=desc, contains three parameters:q(search keyword),page(page number),sort(sort by).
Query String is the most common parameter passing method in HTTP GET requests, and is widely used in search, filtering, paging, tracking and other scenarios.
Q2: What is the difference between GET and POST in passing parameters?
GET request Put the parameters in the URL's Query String (?key=value), the advantages are:
• Ability to add bookmarks and share URLs directly
• Browser cacheable
• Suitable for search, navigation and other side-effect-free operations
POST request The advantages of placing parameters in HTTP Request Body are:
• Parameters will not be displayed in the URL, which is more secure
• Ability to transfer large amounts of data (no length limit)
• Supports multiple Content-Types (JSON, Form, Multipart)
• Suitable for operations with side effects such as login, form submission, etc.
Practical suggestions: Use GET for query and read operations; use POST (or PUT/DELETE) for new, modified, and deleted operations. For sensitive information, always use POST or HTTPS.
Q3: What is URL Encode (Percent-Encoding)? Why is it needed?
URL Encode (also known as Percent-Encoding) is to convert special characters in the URL to % Plus a two-digit hexadecimal code mechanism.
Why do you need coding? Because some characters in the URL havespecial meaning：
• ? → Start Query String
• & → Separate parameters
• = → Separate Key and Value
• # → Start Fragment
• Spaces → not allowed in URL
If the parameter value contains these characters, it must be encoded:
• "hello world" → hello%20world
• "100% done" → 100%25%20done
• "a&b=1" → a%26b%3D1
Available in JavaScript encodeURIComponent() and decodeURIComponent() Encode and decode.
Q4: How to design good Query Parameters? What are some best practices?
The following are suggestions for designing Query Parameters:
1. Use consistent naming conventions
Recommend camelCase(sortBy) or snake_case(sort_by), choose one and be consistent.
2. Parameter names should be descriptive
✅ sortOrder=desc ❌ s=d
3. Avoid URLs that are too long
Browsers have restrictions on URL length (about 2000~8000 characters), and too many Query Parameters may cause the request to fail.
4. Do not send sensitive information
Query String will appear in browser history, server logs, and Referer headers. Sensitive data such as passwords and tokens should not be placed in Query String.
5. URL Encode special characters
Make sure special characters in parameter values are encoded correctly to avoid parsing errors.
6. Consider using array format
For multi-valued parameters, use key[]=val1&key[]=val2 or key=val1,val2 Wait for the clear format.
Q5: Is there a limit to the length of Query String?
Yes, URLs have length limits. But this limitation does not come from the HTTP protocol itself (RFC does not specify the maximum URL length), but from the implementation limitations of browsers and servers:
• Internet Explorer: Approximately 2,048 characters (strictest)
• Chrome: Approximately 64,000 characters
• Firefox: Approximately 64,000 characters
• Safari: Approximately 64,000 characters
• Apache/Nginx server: Default is about 8,000 characters
Practical suggestions: To ensure maximum compatibility, it is recommended to keep the URL length to 2,000 characters Within. If you need to send a large amount of data, you should use a POST request instead and put the data in the Request Body.
Q6: How to deal with arrays or nested structures in Query String?
Query String is essentially a flat key-value structure, but can simulate arrays and nested objects through naming conventions:
Array format (many common practices):
• tag=tech&tag=dev — Duplicate Key (most common)
• tag[]=tech&tag[]=dev — PHP style
• tag=tech,dev — comma separated
Nested objects (many common practices):
• filter[category]=books&filter[price]=10-20 — PHP/Rails style
• filter.category=books&filter.price=10-20 — dot separated
Different backend frameworks parse nested Query Strings differently. This tool parses Key/Value using the most common flat key value. If you need to handle nested structures, it is recommended to use JSON format for delivery.
Q7: Will this tool upload my data to the server?
Not at all. This tool isPure front-end application, all Query String parsing, editing, encoding, decoding, and format conversion are done locally in your browser, and no data is sent to the server. Works even when offline.
Query String usage guide: from basics to advanced
Query String composition structure
A Query String consists of the following parts:
- ?: Flag Query String start
- key: Parameter name, should be descriptive
- =: Connect Key and Value
- value: Parameter value, special characters require URL Encode
- &: Separate multiple parameters
Common applications of Query String in web development
- Search and filter: Such as
?q=keyword&category=books&price=10-50 - Pagination: Such as
?page=2&per_page=20 - sort: Such as
?sort=priceℴ=desc - UTM tracking: Such as
?utm_source=google&utm_medium=cpc - API filtering: Such as
?status=active&created_after=2024-01-01 - OAuth authorization: Such as
?client_id=xxx&redirect_uri=yyy&scope=read - localization: Such as
?lang=zh-TW¤cy=TWD
JSON ↔ Query String application scenarios
In API development, conversion between JSON and Query String is a common requirement:
- Front-end development: Convert JSON setting object to Query String to send API request
- Backend debugging: Convert the received Query String to JSON for logging and analysis
- Postman/cURL test: Quickly convert between JSON and Query formats
- URL share: Convert structured parameters into Query String for easy sharing
- Set up export: Export Query parameters to JSON format and save them
of this tool JSON ↔ Query String The function supports bidirectional conversion, and the conversion results will be automatically synchronized to the editing table above to facilitate further editing and adjustment.