Font size and accessibility – How to design readable texts
An easily readable font is a key component of accessible web design. People with visual impairments, older users, or people with cognitive limitations depend on texts being clearly structured and easy to understand. But even for all other users, an optimal font size contributes to better readability and a pleasant user experience.
In addition to choosing a suitable font size, contrast, font types, and flexible customization options also play an important role. Modern web standards such as the WCAG guidelines set clear requirements for making digital content accessible to as many people as possible. Companies and website operators should take these requirements into account not only for legal reasons, but also to reach a larger target audience and improve user-friendliness.
Why is font size important for accessibility?
Font size plays a crucial role in the readability of texts and thus in digital accessibility. People with visual impairments, older users, and people with cognitive limitations benefit from clearly legible, easily scalable fonts. Fonts that are too small or have poor contrast can lead to a poor user experience and make it significantly more difficult to access information.
For example, while a standard font size of 16px is sufficient for many users, people with visual impairments or dyslexia may need larger font sizes of 18px or more. In addition, it should be possible to change the font size without affecting the content or layout of the page.
You can find out more about the general requirements for accessible websites in our accessibility audit.
Optimal font sizes for different target groups
Not every target group has the same requirements when it comes to font size. Here are a few examples:
- Older people: They often benefit from a font size of at least 18px, as eyesight deteriorates with age.
- People with visual impairments: Flexible settings that allow font sizes of 20px or more are crucial here.
- Mobile users: Since smaller screens require larger fonts, the default font size for mobile views should be at least 16px.
- Legibility in job applications: If you are wondering what font size is ideal for a job application, keep in mind that documents must be easy to read and look professional. As a rule, a font size between 10 and 12px is recommended for job applications.
Contrasts and fonts: What you should keep in mind
Font size alone is not the only factor for accessible display. Contrast and font types also play a major role. According to the WCAG guidelines, the color contrast between font and background should be at least 4.5:1 for normal text and 3:1 for large text.
In addition, sans serif fonts such as Arial, Helvetica, or Verdana are often more readable than decorative fonts. These should be avoided to ensure that the text remains easily accessible to all users. For more information on assistive technologies, see our article on screen readers.
Flexible font sizes thanks to responsive design
Good web design relies on responsive design, which means that content adapts flexibly to different screen sizes. This is particularly important for font size, as users have different requirements depending on their device and eyesight.
Why is this important?
- Better readability on all devices: Text must be easy to read on both a large desktop screen and a smartphone.
- Customizable font sizes: Users must be able to change the font size without affecting the layout or navigation.
- Accessibility through scalability: It is good practice to specify font sizes in relative units such as em or rem instead of fixed pixel values. This allows the font size to dynamically adapt to the user’s settings.
With our Website Accessibility Widget, users can set their preferred font size and contrast options themselves.
Tools for checking the readability of your website
There are various testing and analysis tools available to ensure that your website is accessible:
- Automated accessibility checkers: These tools analyze contrasts, font sizes, and other criteria in accordance with WCAG guidelines.
- Customization tools: Systems that allow users to individually adjust font sizes and colors.
- Browser-based developer tools: Help simulate various visual impairments to check how readable the content is.
Comprehensive accessibility certification can help companies optimize their websites according to the latest standards.
Key findings at a glance
The right font size and a flexible design are essential for a barrier-free website. Users should be able to change the font size without compromising readability or design. Combined with good contrast and scalable typography, this ensures an optimal user experience for all target groups.