URL Query String Parser

What Is a URL Query String?

Every time you search Google, filter an e-commerce site, or click a tracking link in an email, you're using a URL with a query string. A query string is the part of a URL that comes after the ? character and contains key-value pairs separated by &.

Example URL:

https://shop.example.com/results?category=shoes&color=red&size=42&sort=price_asc&page=2

Breaking this down:

• ? — marks the start of the query string
• category=shoes — key: category, value: shoes
• color=red — key: color, value: red
• size=42 — key: size, value: 42
• sort=price_asc — key: sort, value: price_asc
• page=2 — key: page, value: 2

Our URL Query String Parser takes any URL you paste in and instantly displays every parameter in a clean, readable table.

Why Query Strings Get Messy

In practice, query strings are rarely this clean. Real-world URLs often contain:

URL Encoding: Spaces, special characters, and non-ASCII text must be percent-encoded. A space becomes %20, a + becomes %2B, and @ becomes %40. This makes raw URLs unreadable.

https://api.example.com/search?q=iPhone%2015%20Pro%20%2B%20case&lang=en-US

Base64 and JWT tokens in queries: Authentication tokens passed via URL can be hundreds of characters long.

Nested objects: Some frameworks serialize nested JavaScript objects as query strings:

filter[price][min]=10&filter[price][max]=500&filter[brand][]=Nike&filter[brand][]=Adidas

Array parameters: The same key repeated multiple times.

Our parser handles all of these cases and displays the decoded human-readable values alongside the raw encoded versions.

Real-World Use Cases

API Debugging: When testing a third-party API, the endpoint URL often contains authentication tokens, filter parameters, and pagination. Paste the full URL to instantly see what parameters are being sent without counting characters manually.

Affiliate & Tracking Links: Marketing URLs contain utm_source, utm_medium, utm_campaign, and dozens of other tracking parameters. Parse any link to see exactly what data it sends back to analytics systems.

E-commerce Filtering: Filter and sort state is often stored entirely in the URL query string. Parsing it helps understand how a platform's filter system works.

Redirect Debugging: SAML SSO, OAuth callbacks, and payment gateway redirects carry encoded payloads in their query strings. Decoding these is esse...