In this article, we’ll provide a thorough understanding of query parameters with examples.
Table of Contents
What is a Query Parameter?
A query parameter is a set of parameters (key-value pair) appended to the end of a URL. They’re URL extensions that provide additional information to a server when making requests. In other words, query parameters let us define customized content or actions based on the information we’re passing.
Take, for example, this URL:
In this example, there are two query parameters:
- ‘category’ with the value “Electronics”
- ‘brands’ with the value “[Samsung, LG, Sony]”
These parameters can be used to instruct the web server how to process the request, such as displaying products from the “Electronics” category and filtering them based on the brands “Samsung,” “LG,” and “Sony.”
An ampersand (&) is used between each parameter to add multiple query parameters, such as in the above example. This forms a query string parameter.
What is a Query String?
A query string is formed by putting a “&” sign between numerous query parameters. Basically, all URLs on the Internet can be broken down into three parts: protocol, file (or application) location, and query string/query parameter. In a browser, the technology used is nearly always HTTP; the address is the standard form of the hostname and filename, and the query string is whatever comes after the question mark sign (“?”).
A query string is essentially the part of a URL that contains data provided to a web-based application or a back-end repository. The HTTP protocol is stateless by nature; therefore, query strings/query parameters are required. You must maintain a state for a website to be anything more than a brochure (store data). There are several options: you can utilize something like session state server-side on most web servers. Cookies can be stored on the client. You can also use it to store information in the URL.
Why Do We Need Query Parameters?
Query parameters allow us to sort content on a page. For example, e-commerce stores can use query parameters to display products from a specific category and filter them based on brands. This makes it easier for users to navigate and find their desired products. Additionally, with query strings or query parameters, users can request a specific page according to their requirements with query strings or query parameters.
Query parameters can also be used to implement pagination by specifying the number of results per page and the page number. This allows users to navigate efficiently.
Moreover, a query string provides useful information to other tools like Google Analytics. Google Analytics has a UTM tracking feature that allows us to categorize traffic based on where it came from.
In other words, UTM tracking shows you exactly where a person was before visiting your website. This is quite important for measuring the effectiveness of specific marketing campaigns and backlinks.
What are API Query Parameters?
API query parameters allow us to pass information to an API URL in a simple and easy way. We can use these parameters in REST API when making requests to various endpoints. These are additional key-value pairs that occur after the question mark in the API URL. They’re essentially URL extensions that help decide certain content or actions based on the data being sent.
A “?” is used to attach query parameters to the end of the URL. In other words, we use a question mark symbol to separate path and query parameters.
Take, for example, this weather API request:
- https://api.weatherstack.com/current is the endpoint.
- ? marks the beginning of the query string.
- access_key=YOUR_ACCESS_KEY is a query parameter where ‘access_key’ is the key, and ‘YOUR_ACCESS_KEY’ is its corresponding value. This parameter serves as an authentication mechanism to access the Weatherstack API. It should be replaced with an actual access key provided by Weatherstack.
- & is used to separate multiple query parameters within the query string.
- query=New York is another query parameter where the ‘query’ is the key, and ‘New York’ is its corresponding value. This parameter specifies the location for which the current weather data is requested, in this example, New York.
It’s important to remember that query parameters can play an important role in attribution. However, it’s also key to ensure that your attribution strategy is cross-platform and functioning as well as it possibly can.
How to Use API Query Parameters?
Always consult API documentation before utilizing query string parameters. This is because not all APIs are created equal, and not all query string formats will work with the API. However, you must follow some basic guidelines for efficient data filtering.
After the base URL and path parameters, a question mark (?) is added to the endpoint to add query string arguments (if any). The query strings that follow the “?” define different parameters and variables, as discussed in the previous section.
The parameters can be linked, one after the other, or separated by an ampersand (&). It makes no difference what order the parameters are in.
However, query strings differ between APIs. So, once again, it’s critical to consult the documentation to see what features are available. For example, limit, offset, and page are frequent query string arguments in bigger API databases. Limit specifies how many resources/instances you want to be retrieved, while offset specifies where the count should begin.
What About Enterprise Usage of Query Parameters?
Communication with a server is one of the purposes of query strings. It accomplishes this by exchanging information.
In addition, enterprises can use query strings in marketing tools. As discussed earlier, we can utilize query strings with UTM parameters to tell Google Analytics to sort traffic by source. We can also design our own UTM tracking tool.
Tracking site searches is another application of query strings. This is quite useful for tracking product sales on eCommerce sites. We can also use a query string to pass values interactively and modify emails or website greetings.
Conclusion
A query parameter is essentially a set of parameters (key-value pair) added to the end of a URL after the question mark “?” symbol. They are URL extensions that provide additional information to a server when making requests. A key and a value are distinguished by an equal sign (=) in URL parameters. Additionally, the ampersand (&) is used to join multiple query parameters.
In an API, query string parameters are displayed after a question mark (?) in the endpoint. The parameters and their values are immediately followed by the question mark (?), commonly referred to as the “query string.” When used correctly, this is the most straightforward approach to adding basic screening to RESTful APIs.
Frequently Asked Questions (FAQs)
What Is a Query Parameter in a URL?
URL parameters (also known as “query strings” or “URL query parameters”) are elements added into URLs to help you select and organize material on your website, as well as track information. In a nutshell, URL parameters allow you to convey information about a click through the URL.
What is an example of a query parameter?
Take this URL as an example:
https://example.com/search?q=apple&category=fruit&page=1
In this URL:
- The query string is: ?q=apple&category=fruit&page=1
- The query parameters are:
- q=apple
- category=fruit
- page=1
What are query parameters in API?
In an API, query string parameters are used after a question mark (?) in the endpoint. They help decide certain content or actions based on the data being sent.
Why use query parameters?
Query parameters can be used for various purposes, such as sorting content on a page, implementing pagination by specifying the number of results per page, etc.
