Query String Parser
Free online query string parser. Extract and decode URL query parameters instantly. View key-value pairs with automatic URL decoding. Useful for debugging APIs and tracking parameters.
Enter a URL above to see parsed query parameters.
How to Use Query String Parser
Enter a URL or Query String
Paste a full URL with query parameters, or just the query string portion (starting with ? or &). The tool accepts both formats.
View Parsed Parameters
Each query parameter is extracted and displayed as a key-value pair. URL-encoded values like %20 are automatically decoded to their original form.
Use the Data
The parsed output shows all parameters clearly. Useful for debugging API calls, inspecting tracking parameters, or understanding how a URL passes data to the server.
Example
https://example.com/search?q=hello+world&page=2&sort=price&utm_source=google&utm_medium=cpc | Key | Value |
|---|---|
| q | hello world |
| page | 2 |
| sort | price |
| utm_source | |
| utm_medium | cpc |
Frequently Asked Questions
What is a query string?
A query string is the part of a URL after the question mark (?). It contains key=value pairs separated by ampersands (&). For example, in "https://example.com/search?q=hello&page=2", the query string is "q=hello&page=2" with parameters q=hello and page=2. Query strings pass data from the browser to the server — search terms, page numbers, filters, tracking IDs, and more.
What does URL encoding mean?
Special characters in URLs must be encoded to avoid ambiguity. Spaces become %20 (or +), ampersands become %26, equals signs become %3D. Our parser automatically decodes these for you. For example, "q=hello%20world" becomes q=hello world. If you need to manually encode or decode, use our URL Encode/Decode tool.
Why would I need to parse query strings?
Common use cases include: debugging API requests by inspecting all parameters, understanding UTM tracking parameters in marketing URLs, extracting search terms from referral URLs, checking pagination parameters in scraped URLs, and verifying that OAuth redirect URLs contain the expected parameters like code and state.
Does this handle duplicate parameter names?
Yes. Some URLs contain the same parameter multiple times — like ?filter=red&filter=blue for selecting multiple filter values. Our parser groups duplicate keys, showing all values for each parameter name. This matches how web frameworks like Express.js and Django handle repeated query parameters.
Common Uses for Query String Parsing
Query strings carry the data that makes the web interactive — search terms, filters, pagination, tracking codes, and authentication tokens. Being able to parse them quickly helps you debug, analyze, and build better web applications.
Practical Scenarios
- Marketing analytics: Decode UTM parameters (utm_source, utm_medium, utm_campaign) from referral URLs to understand traffic sources
- API debugging: Inspect all query parameters in API request URLs to verify they match the expected contract
- OAuth troubleshooting: Check redirect URLs for required parameters like code, state, and scope
- SEO audit: Extract search queries from Google referral URLs (look for the "q" parameter)