Icons are a universal language that helps users navigate and function digitally. From a design perspective, many considerations go into creating icons that are eye-catching and understandable. One of the primary considerations is whether to choose solid and outline icons. Let’s look at what makes solid and outline icons different and how they function as an essential element of digital design.

What is an Outline Icon?

Outline icons have subtle characteristic figures that appear on the outer edges of the hero. This style emphasizes the simple shape of the icon and allows small visual changes to communicate a variety of meanings.

What is a Solid Icon?

Solid icons grab the users’ attention with a simple design and careful coloring. As you can see in the image below, the solid icons stand out more than an outline icon, and as a result, they don’t need to contain as many subtle cues or shapes around the edge of the icon. Hollow icons rely on the shape to attract attention, whereas solid icons draw the eye with their color.

Icons are a Universal Language

With the design, you can accomplish so much through the effective deployment of strong visual elements. It doesn’t matter what language you speak. We can communicate and completely understand each other with visual cues. Icons are a great example of this.

Everyone unconsciously interacts with symbols and icons every day. They are a design element capable of conveying a message that is universally understood. As a result, they are incredibly powerful tools for user experience (UX) and user interface (UI) designers. Icons can add to the aesthetic value, engage a user’s curiosity and encourage experimentation.

Functional + Familiar = Useful

Users should not have to decode the meaning of icons. An icon must be immediately understandable without labels or additional explainers. The icons we use every day have accumulated meaning over time and maintain meaning through their context. Designers of digital icons must be aware that for an icon to be useful, it has to be both familiar and functional.

Icons are Inclusive

Icons are a common visual vocabulary that means that anyone from any walk of life should understand their meaning. Everyone knows that a red heart icon is meant to communicate love. Similarly, we all know that an icon with a smiling face is intended to share happiness. One of the reasons icons are a powerful design tool is because they are so inclusive.

Functional Icons

Icons can be found everywhere in everyday life. They are often used to guide public places like airports, stations, parks, and shopping malls. Available icons are a specific type of icons that are even more general and recognizable than the digital icons seen on phone and computer screens.

Solid vs. Outline Icons

So which icons should designers use to ensure a great UX? And how do solid and outline icons compare?

In general, the effectiveness of an icon relates to how quickly a user can recognize the icon and understand its meaning. When creating an icon, there are plenty of elements with which you can experiment, including dynamics, color, space, shape, and texture. For solid icons, you can utilize all of these elements, whereas, with an outline icon, you can only experiment with shape and space to make something that connects with users.

Are Solid Icons More Recognizable?

Research had shown that, in general, solid icons were more instantly recognizable than outline icons, mainly when those icons represented an identifiable item from the real world. A solid icon is usually a more accurate representation of the actual life item than an outline.

When to use Solid vs. Outline Icons?


  • Use outline icons if you need to make subtle characteristic cues more noticeable
  • Use outline icons if you have information along the edges of the icon that you want to highlight
  • Use outline icons if the design is simple and they are no elements within the icon that need to be distinguished


  • Use solid icons to represent physical, real-world objects
  • Use solid icons to represent the work done by a physical object
  • Use solid icons to make characteristic cues and details on icons easier to identify
  • Use solid icons if you want to highlight a particular color

Overall, for icons that aim to express the exact meaning of the original subject, it is usually best to make them solid. On the other hand, for icons that have abstract or loosely defined meanings, then hollow or outline icons are often better. There are various ways to make your icons eye-catching and appropriate in both cases. In the end, the type of icon that designers will create and use will depend on the ultimate purpose of that icon, the brand’ how effectively a user can understand its meaning.

To learn more about how you can effectively use icons to improve your user experience feel free to contact our UX experts.