Query String Parser and Builder

This tool makes query parameters visible as rows and rebuilds them with standard component encoding.

Designed for: Web developers and QA testers debugging links, filters, and API requests.

How to use this tool

Paste a full URL or query string to parse it, or add rows and build a query. Review repeated keys, blank values, and parameter order when comparing requests.

How the result is produced

The browser URL and URLSearchParams APIs parse and serialize the query component. Repeated keys remain repeated rather than being silently collapsed into one value.

Test examples

`?tag=red&tag=blue` contains two values for the same key. Spaces may be serialized as `+` by URLSearchParams, so compare decoded values rather than assuming one textual form is the only equivalent.

Limitations

The tool does not validate server routes, authentication, signatures, cache behavior, or whether a parameter is safe to expose in a URL. URLs can be recorded in history and logs.

Privacy and processing

Parsing and building happen in the browser. Avoid pasting tokens, personal data, or private query values into a public page.

Related guide

Query parameters are visible data, not a private channel

Related tools in this category

• URL Encoder and DecoderUse this for query values and URL components, not for blindly re-encoding a complete URL.
• HTML Entity Encoder and DecoderConvert text to safe visible entities or decode common entities back to characters.
• CSS Minifier and FormatterPaste CSS and choose a compact or readable output for inspection.

Documentation

• https://developer.mozilla.org/en-US/docs/Web/API/URLSearchParams
• https://www.rfc-editor.org/rfc/rfc3986

This page describes the implementation shipped with the NOFYI Tool Factory. Review the interface output before using it in a production workflow.