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Query String Builder

🔒 In your browser

Build & edit query strings from key/value pairs.

How it works

Build a query string from key/value pairs — each value is percent-encoded correctly, so spaces and & inside a value won't break the URL. Or paste an existing URL to pull its parameters into the table and edit them.

q=blue+suede+shoes&page=2

Parameters

Query string
q=blue+suede+shoes&page=2
Full URL
https://example.com/search?q=blue+suede+shoes&page=2

Spaces become + in query strings (the standard form-encoding), which servers decode back to spaces.

About the Query String Builder

Building a query string by hand is easy to get wrong — a stray space or ampersand can break the whole link. This free query string builder lets you add key/value pairs and get a correctly encoded query string and full URL, every time.

It runs in your browser and keeps your data private.

How to build a query string

  • Add key/value pairs for each parameter.
  • Get a correctly percent-encoded query string and complete URL.
  • Edit or remove pairs and watch the output update.

How encoding keeps links from breaking

Certain characters have special meaning in a URL — a space, an ampersand, a question mark, a hash. If they appear raw inside a parameter value, they truncate or corrupt the link. Percent-encoding replaces them with codes like %20 and %26 so the value survives intact. This builder encodes every value for you, so you never ship a broken URL.

Frequently asked questions

What is a query string?

The part of a URL after the ? that carries parameters as key=value pairs separated by &, used to pass data like search terms, filters or tracking tags.

Does it encode special characters?

Yes. Spaces, ampersands and other reserved characters in your values are percent-encoded so the resulting URL is always valid.

Is my data private?

Yes. The query string is built locally in your browser.

Is a space encoded as + or %20?

Both appear in the wild. In the query string, + historically means a space (from form submissions), while %20 is the general percent-encoding. %20 is always safe; this builder uses correct encoding so values decode back exactly.

Related searches

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Copy this and paste it into your page's HTML. The tool runs in the visitor's browser, just like here. Change height to fit, or add the optional auto-resize snippet below. Add ?theme=dark to the URL for dark mode.

<iframe src="https://toolhq.dev/embed/query-string-builder/" title="Query String Builder — ToolsHub" width="100%" height="520" style="border:1px solid #e5e7eb;border-radius:12px;max-width:680px" loading="lazy"></iframe>
Optional: auto-resize the iframe height

Add this once on the same page so the iframe grows to fit the tool:

<script>
addEventListener("message", function (e) {
  if (e.data && e.data.type === "toolshub:resize") {
    document.querySelectorAll('iframe[src*="/embed/"]').forEach(function (f) {
      if (f.contentWindow === e.source) f.style.height = e.data.height + "px";
    });
  }
});
</script>