How do you choose the best font size and line height for web readability?

1 Why font size and line height matter

Font size and line height are two of the most important factors that affect how easy it is to read text on a screen. Font size determines how big or small the letters are, while line height controls the vertical space between the lines of text. Together, they influence the legibility, readability, and aesthetics of your web content.

2 How to measure font size and line height

Font size and line height are usually measured in different units, depending on the context and the device. For web development, the most common units are pixels (px), points (pt), ems (em), and rems (rem). Pixels are absolute units that correspond to the physical dots on the screen. Points are relative units that are based on the print standard of 72 points per inch. Ems and rems are relative units that are based on the font size of the parent element or the root element, respectively.

3 How to choose font size and line height

Finding the right font size and line height for web readability can be tricky, as it depends on various factors such as the font family, the screen size, the contrast, and the audience preferences. However, there are some general guidelines and best practices that you can follow to make your web typography more readable. For instance, a comfortable and consistent font size for body text is usually between 14px and 18px, while headings should be between 20px and 32px. The line height should also be proportional and balanced for your font size - a common range is between 1.2 and 1.5 times the font size. Additionally, choose a font family that is clear and suitable for your web content - one that has good legibility, readability, and compatibility across devices and browsers. Finally, pick a color scheme that provides enough contrast and harmony for your web typography - colors that are easy to distinguish from the background, complement each other, and fit with your brand identity.

4 How to test font size and line height

Once you have chosen your font size and line height, it is important to test them on different devices and browsers to ensure they look and perform accordingly. To do this, you can resize your browser window to check how your web typography adapts to different screen sizes and resolutions. Additionally, you can use a web accessibility tool or a browser extension to check the contrast ratio and the color blindness compatibility of your web typography. Furthermore, you can use a web performance tool or a browser extension to check the loading speed and the resource consumption of your web typography. Finally, you can use a web analytics tool or a survey to collect feedback and data from your visitors about their web readability experience.

5 How to improve font size and line height

Finally, you should always strive to enhance your web readability by updating your font size and line height according to the latest web standards and best practices. Experimenting with different font families, color schemes, and layout options can help you find the best combination for your web content. Additionally, applying web typography principles and techniques such as hierarchy, alignment, spacing, and emphasis can further improve your web readability. You can also look to other web developers and designers who have mastered web typography and color theory for guidance.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?