DevToolbox

URL Query String Parser: Decode and Edit Parameters

2026-05-24

Quick Answer

Quick Answer: Paste any URL or query string into our URL Params Parser to see decoded parameters in a table, edit values, and copy the rebuilt URL.

What is a query string?

Everything after ? in a URL is the query string: ?q=hello&lang=en has keys q and lang. Values are often percent-encoded (%20 for space, UTF-8 for non-ASCII).

Common use cases

  • API debugging — inspect page, limit, and filter params
  • Marketing links — read UTM tags (utm_source, utm_campaign)
  • OAuth redirects — decode code and state without manual unescaping
  • Fix broken links — change one param and regenerate the URL

Query string vs URL encoding

ToolPurpose
URL EncoderEncode/decode a single string
URL Params ParserSplit, edit, and rebuild full query strings

Try It Yourself

Parse your next API URL with the URL Params Parser

Frequently Asked Questions

How are plus signs handled?

In query strings, + often means space. Our parser uses standard URLSearchParams behavior.

Can I paste only ?foo=bar?

Yes—paste a full URL, a path with query, or just the query portion (with or without leading ?).

Duplicate keys?

URLSearchParams may combine duplicate keys; our table shows each entry from the parsed result.

Try it yourself

Use our free URL Parameter Parser — no signup required.

Open URL Parameter Parser →