# Query string builder — no upload

> Build and encode a URL query string from key/value pairs in your browser. Nothing is uploaded — the parameters stay in the tab.

Build a properly encoded URL query string from key/value pairs, handling escaping and repeated keys. The string is built locally, so nothing is uploaded.

Assembling a query string by hand invites encoding bugs. Building it from key/value pairs guarantees correct escaping and makes repeated or complex parameters straightforward.

To take a URL apart instead, use the URL parser; to encode a single value, the URL encoder.

## How to

1. **Add pairs.** Enter each parameter key and value.
2. **Build.** The encoded query string is assembled.
3. **Copy.** Append it to your URL.

## FAQ

### Does it encode values correctly?

Yes. Values are percent-encoded so special characters don't break the URL — no need to escape each one by hand.

### Can it handle repeated keys?

Yes. Add the same key multiple times for array-style parameters, which the builder serializes correctly.

### Is anything uploaded?

No. The query string is built locally in the tab.


## Related tools

- [URL parser](https://www.safepaper.app/dev/url-parser)
- [URL encode](https://www.safepaper.app/dev/url-encoder)
- [cURL to code](https://www.safepaper.app/dev/curl-to-code)
- [HTTP client](https://www.safepaper.app/dev/http-client)

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Canonical HTML: https://www.safepaper.app/dev/query-string
Markdown: https://www.safepaper.app/dev/query-string.md

There is no upload endpoint — your files are processed in this browser tab. Open your network tab and check.