Understanding a Data Attribute Like a Pro Web Developer

Posted on March 27, 2024 | Updated on April 18, 2024

A data attribute is an essential facet of web development. It encompasses the breadth and detail of code and notifies the rest of the inputs how to interact with one another. Let’s uncover the secrets behind maximizing the benefits of data attributes, whether you’re a newcomer in the web development scene or need a refresher. 

Knowing code and how to leverage data attributes is becoming a more desired skill for design, tech and many other professionals — so, get ahead of the game.

What Is a Data Attribute?

A data attribute provides custom context to code. It is global, therefore it can meld with all HTML elements, like “accesskey” and “style.” It is seen formatted as: 


Attributes expand on the foundational information that would otherwise not make sense in standard attributes. 

Adding data attributes will not alter how the code functions, but it merely adds detail and associations to existing frameworks. Sometimes they manifest as key-value pairs to better define a data set. They can support common attribute references, like type, length, count, and operation code.

lines of code

It is a smart, functional way to input private page- or application-specific information into the elements. Why would web developers customize code like this? Wouldn’t it make it unnecessarily complicated? The effort pays off in increased user experience. Plus, the user agent doesn’t consider custom code.

What is the anatomy of a data attribute, and are there rules for how to construct it? Yes, and they are easy to remember. First, there should be no capital letters present. Secondly, there has to be at least one character after the data- prefix. When it comes to the value, it can be a string of infinite possibilities. They typically follow list tags, whether ordered or unordered:

<li>, <ul>, <ol>

It’s essential to note data attributes are only browser-supported in specific versions. If they are not up-to-date, then they may not work properly. These are the minimum versions required for full compatibility, though previous versions may offer partial functionality:

  • Google Chrome: 7
  • Microsoft Edge: 12
  • Firefox: 6
  • Safari: 5.1
  • Opera: 15

Is Attribute Data Different?

A data attribute and attribute data are different concepts. In short, data attributes are additional, custom pieces of information. You can use JavaScript and CSS to manipulate it to serve your purpose. Data attributes are for programming purposes.

Attribute data is more of a generalized umbrella term for data analysis instead of execution. It encompasses quantitative data, whereas its counterpart, variable data, is measurement-based. Attribute data recognizes a set by its characteristics, determining if it does or doesn’t meet a specific trait. Gathering attribute data happens in countless ways, from gathering customer surveys to analyzing public records. It depends on the intention and application behind the data use.

For example, attribute data perspectives can view how much information is labeled “green” versus “yellow.” Most attribute data can follow a yes or no flow and determine whether it has that quality or not. 

Variable data informs how green or yellow those data points are. The two combined provide a holistic overview of what the data contains, its quality, and its diversity. Attribute data is ideal for modeling to understand data, and employing data attributes is curating code to store more specific details.

person drawing a flow chart

What Are Examples of Data Attributes and Their Use Cases?

If you’re just learning how to code or have a limited view on what data attributes can provide, here are a few examples.

Say you’re setting up an ecommerce store and each item needs to have the base price attached to it to make sense when programming a sale. The data attribute might look like this:


Then, the developer can use JavaScript to interact with that stored information. If the site needs to apply a sitewide discount, it can interact with this data attribute to automatically create a seamless experience. However, this example is unique because it implies the retailer doesn’t want the base price to be visible. Remember — custom data attributes are not accessible. If you want this information available, do not make it follow this format.

Another example would be coding employee IDs in a list.

<h1>Employee Information</h1>

  <li data-id="108">John Smith</li>
  <li data-id="765">Jerry Smythe</li>
  <li data-id="333">Jimmy Smuthe</li>

You can see how the names are now associated with a private yet stored employee ID for quick association and identification.

This example explores how categories can provide even more meaning to metadata:

  <li data-id="mammal">Bear</li>
  <li data-id="bird">Parrot</li>
  <li data-id="mammal">Whale</li>
  <li data-id="fish">Goldfish</li>

In this list, the data attributes define the relationships between data points.

However, these are only lists. What do data attributes look like with more complexity? Consider how game developers code sprites. For players to interact with them appropriately, they have to have a lot of qualities. Imagine crafting a farming simulator:

  onclick="crops[this.dataset.cropId].harvested()" />

You could see how conditional and personalized this data could become.

laptop with code

How Do You Access Data Attributes?

Once you have an updated browser, you can dive into using data attributes. It’s fairly straightforward in whatever markup language and style sheet you are in. Let’s start with writing the content, designing it in a way that makes sense, then making it usable.


Using the right syntax for data attributes in HTML doesn’t always have to look like the aforementioned examples. You can store information visually or not. Reading them only requires you to search for the attribute qualifiers.


The CSS attribute selectors must match the HTML in order to access them. Display parent data with the attr() function.


Reading data attributes in JavaScript is simple. All you need is the HTML name and getAttribute(), though there are other ways, including using a DOMStringMap. 

What Are the Benefits of Data Attributes?

Programming changes happen constantly, which is why there are strict ways to use HTML. Inventing attributes out of the blue not only limits functionality, but it ignores how it will develop in the future. Who knows if those imagined attributes will become relevant or functional? Custom data attributes prevent those what-if scenarios from arising while still getting malleability from your code. 

It makes code timeless and resilient. It is an avenue to take without resorting to non-standard attributes or hacks, which makes behaviors consistent across developers.

It also makes referencing information more streamlined. Its unique format makes it an easy identifier for all programs to know that it is a custom attribute, making it easier for multiple programmers to translate what is and isn’t necessary in a code. It prevents unnecessary conflicts with other scripts while providing peace of mind for what the coder wants transparent and not.

A Data Attribute’s Utility

Data attributes input meaning into otherwise disconnected code. You can store more information with clever data attribute incorporation without other complicated measures and properties on the DOM. Developers might have other preferred methods to achieve a similar effect, however data attributes are versatile and straightforward tools every developer should keep in their toolkit.

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