Why Icons Fail: Hidden Usability Pitfalls and How to Fix Them

Icons can bring the following benefits to a graphical user interface (GUI):

1. Create good click areas : Icons are usually large enough for easy tapping on touch screens and easy clicking with a mouse. Text links can cause asymmetry between reading and clicking on touch screens.

2. Save space : Icons are compact, allowing many icons to be displayed in toolbars, panels, and other controls within limited space.

3. Enable quick recognition (when well designed) — especially for common or familiar standard icons. Icons designed with cultural differences in mind are internationally universal. For example, mailboxes look different across countries, but the envelope is the same, making it a more universal icon for email.

4. Meet and enhance aesthetic design goals.

5. Consistent use across products can convey a product family concept and strengthen the connection between products.

However, if design does not fully consider potential icon issues, they can cause usability problems.

Few universal icons

Users only have universal recognition for a few icons, such as home, print, and the magnifying glass for search. Most other icons are ambiguous because they are used differently across interfaces, leading to a lack of standardization and making icon usage a design pain, as users cannot expect the same meaning each time they see an icon.

The three‑line “hamburger” icon is a good example. In many apps it represents the main navigation menu, but some use a similar icon to open a list of common items (e.g., Buy Me a Pie). Placing the icon to the right of an input field, where users expect a submit button, adds further confusion.

Heart and star icons are also frequently misunderstood. They often represent like, bookmark, rating, or other user feedback. Users’ confusion stems from differing functions across sites and the contrast between the two icons, making their meanings hard to remember and explain. For example, on the travel site Combadi the heart icon marks a trip as “liked” but does not save it for later review, and users preferred likes only from people who actually purchased the trip. In contrast, the interior‑decor shopping site Fab uses the heart icon to save the item for later.

Even small differences in function or meaning can hinder users’ understanding and trust when they see the icon again.

Last week (the article was published on July 27) we released a usability report on a website’s clock icon in the main navigation. Although the graphic is highly recognizable as a clock, its meaning in this case is vague because the site uses it for navigation history, opening a sidebar with recent pages. No test participants clicked it. A vague icon equals a meaningless function.

Icons need text support

Almost all icons encounter ambiguity. To solve this, we should pair icons with textual labels so users can understand their meaning in context. Even for standard icons, adding text is safer, especially if you have customized the icon aesthetically.

Icon text should always be visible, not shown or hidden based on user interaction. For navigation icons, text is especially critical. Do not rely on hover‑to‑show text: this raises interaction cost and does not work on touch devices.

Usability.gov displays quick‑navigation icons on every page of its site, linking to design methods, documentation, templates, and specifications. If I asked each reader to send me an icon that represents “design methods,” I would receive many different answers. As we noted years ago in the “Website Homepage Usability Design Guidelines,” using icons in navigation makes them hard to recognize. While the mobile version shows text alongside icons, the desktop version hides the text, showing it only on hover, which forces users to discover the text to understand the navigation, reducing efficiency.

Relative size helps attract user attention

Icons tend to be more noticeable on mobile than on desktop or app interfaces. It is easy to assume that an icon that looks fine on mobile will work the same on desktop, but this is not true. Mobile screens have limited space, so only a few elements compete for attention. On desktop, the larger screen contains many elements, and an icon can be easily overlooked unless it occupies a relatively large portion of the header. For example, a hamburger menu icon may occupy 20‑25% of the header width on a standard mobile site, but the same size on a desktop makes the icon appear tiny (around 3.5% of the width), reducing its visibility.

To address this, designers can display the full menu on larger screens instead of keeping it hidden behind a small hamburger icon, improving discoverability and avoiding usability issues caused by hidden navigation.

Small tips for icon design

When you decide to design icons for your interface, start with research! Look at competitors’ or platform‑standard icons because those are most familiar to users.

If you must create a new icon, follow these guidelines to make it easy to recognize and remember:

Keep it simple. Reduce graphic detail and avoid excessive personalization; simple icons are easier to recognize at small sizes.

Apply the five‑second rule: if it takes you more than five seconds to decide on an appropriate icon, the meaning is probably too complex to convey with a single image.

Test recognizability: ask people what they think the icon means.

Test memorability: after explaining the meaning, check again weeks later whether they still remember.

Use textual support. As Bruce Tognazzini (NNGroup chief designer) said, “A word is worth a thousand pictures.”