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Query String Parser Developer

Break a URL into its parts and list every query parameter.

Query String Parser is a free online tool that break a URL into its parts and list every query parameter. It runs entirely in your web browser using plain JavaScript, so files are processed on your own device and never uploaded to a server. There is no sign-up, no file size limit imposed by the site, no watermark and no paid tier.

Price
Free — no account, no quota, no watermark
Category
Developer
Where it runs
In your browser, on your device
Files uploaded
None
Technology
plain JavaScript
Settings
None — it just works
Works offline
Yes, after the first visit

About Query String Parser

A query string is broken into its parameters, including the case most parsers get wrong: a repeated key. `?tag=a&tag=b` is legal and common, and there is no standard saying whether it means "the last one wins" or "a list" — PHP, Rails and Express all answer differently. Repeated keys are shown as a list here so you can see exactly what is there.

How to use it

  1. Paste the text you want to run through query string parser.
  2. There is nothing to configure — the result updates as you type.

Under the hood

Runs onplain JavaScript — runs the whole thing

Questions

What happens with duplicate parameters?

All values are shown. Which one your server uses depends on its framework: PHP takes the last, Rails needs `tag[]` for an array, and Node's URLSearchParams exposes all of them.

Are values URL-decoded?

Yes, including `+` as a space, which is the form-encoding convention that applies inside a query string specifically.