Query Parameters

Query parameters are key-value pairs appended to a URL after a question mark to send additional data to the server. Multiple parameters are separated by ampersands. They are commonly used for search queries, filtering results, sorting, pagination, and tracking. Query parameters make URLs bookmarkable and shareable while allowing dynamic content based on user input.

An e-commerce product listing uses query parameters for filtering: /products?category=shoes&color=red&sort=price_asc&page=2&limit=20. The server parses these to return only red shoes, sorted by price from low to high, showing the second page of 20 results. Users can bookmark this filtered view or share the exact URL with others to show the same results. The frontend reads these parameters to update UI state.