Free URL Query String Builder that works offline
Create a correctly encoded query string without manually placing question marks, ampersands and percent escapes.
What this url query string builder does
URLSearchParams handles reserved characters and repeated keys consistently. The builder separates editing from encoding so spaces and Unicode values are not corrupted.
How to use the URL Query String Builder
- Enter or paste a base URL plus query parameter names and values into the tool.
- Adjust the available options so they match the format and result you need.
- Choose Build URL and review an encoded URL and decoded parameter preview before using it.
- Copy or download the result, then clear the page if the input was sensitive.
Common uses
- Preparing API request URLs
- Building analytics-free test links
- Checking repeated query parameters
- Learning URL encoding behavior
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
- Do not place secrets in URLs because they may enter logs and history.
- Use the URL parser to inspect an existing address.
- Fragments are preserved after the query string.
Frequently asked questions
Does this tool upload my data?
No. URL Query String Builder processes its input in the current browser and does not submit it to a conversion API.
What input does the URL Query String Builder accept?
Absolute and relative URLs are supported when the browser URL parser can resolve them. Repeated parameter names are preserved.
Can I use this tool offline?
Yes. Once the Offline Tools PWA has cached the page, the core feature works without an internet connection.