Free Query String Parser that works offline
Inspect query parameters as formatted JSON or create an encoded query string from a small object. Repeated keys are preserved as arrays instead of being silently overwritten.
What this query string parser does
URLSearchParams applies browser-standard percent encoding and decoding. Converting to JSON makes values easier to inspect, while builder mode handles reserved characters and repeated array values consistently.
How to use the Query String Parser
- Enter or paste a query string, complete URL or JSON object into the tool.
- Adjust the available options so they match the format and result you need.
- Choose Query to JSON or JSON to query and review the equivalent structured or percent-encoded representation before using it.
- Copy or download the result, then clear the page if the input was sensitive.
Common uses
- Debugging search and filter URLs
- Building callback parameters
- Inspecting repeated tracking keys
- Creating encoded test queries from JSON fixtures
Private processing and offline access
This tool does not submit your input to a conversion server. Processing takes place inside the browser using local JavaScript and standard Web APIs. After the PWA has been installed or cached, the page and its core features remain available without an internet connection. Closing or clearing the page removes unsaved input; the tool does not create an account or cloud history.
Tips for accurate results
- Query values are strings even when they look numeric.
- A plus sign may decode as a space in form-style queries.
- Use a full schema when applications require typed parameter validation.
Frequently asked questions
Does this tool upload my data?
No. Query String Parser processes its input in the current browser and does not submit it to a conversion API.
What input does the Query String Parser accept?
Leading question marks and complete URLs are accepted for parsing. Builder mode expects a JSON object; array values become repeated keys.
Can I use this tool offline?
Yes. Once the Offline Tools PWA has cached the page, the core feature works without an internet connection.