When it comes to styling text on a website, one of the most commonly used properties is font size. It allows web developers to control the size of text and make it more readable and visually appealing. However, there are two main units of measurement for font size in CSS: percentage (%) and em. Many developers debate which one is better to use, but the truth is, each has its own advantages and disadvantages. In this article, we will delve into the differences between the two and help you decide which one is best for your website.
Let's start by defining what percentage and em mean in CSS. Percentage is a relative unit of measurement that is based on the font size of the parent element. For example, if the parent element has a font size of 16px and the child element has a font size of 50%, it will have a font size of 8px (50% of 16px). On the other hand, em is also a relative unit of measurement, but it is based on the font size of the element itself. So if the parent element has a font size of 16px and the child element has a font size of 2em, it will have a font size of 32px (2 times the font size of the parent element).
One of the main advantages of using percentage for font size is that it allows for more consistent scaling across different screen sizes. This is because it is based on the font size of the parent element, so it will adjust accordingly. This makes it a popular choice for responsive web design, where the font size needs to adapt to different screen sizes. On the other hand, em is more flexible as it is based on the font size of the element itself. This means that you can have different font sizes for different elements, giving you more control over the design.
Another advantage of using percentage for font size is that it is easier to calculate and maintain. Since it is based on the parent element, you only need to change the font size of the parent element to make changes to all the child elements. This can save time and effort, especially when dealing with large websites with multiple pages. On the other hand, using em can be more complex and time-consuming, as you need to calculate the font size for each element individually.
However, one of the main disadvantages of using percentage for font size is that it can lead to inconsistent font sizes. This is because it is based on the font size of the parent element, which can vary from page to page. This can result in some elements having a font size that is too small or too large, making the design look unbalanced. On the other hand, em can be more consistent as it is based on the font size of the element itself.
Another disadvantage of using percentage for font size is that it can be limited in terms of design choices. Since it is based on the font size of the parent element, it can only be scaled to a certain extent. This can be a problem when trying to achieve a specific design or when working with different font sizes. On the other hand, em allows for more precise and granular control over font sizes, giving you more design options.
In conclusion, both percentage and em have their own advantages and disadvantages when it comes to font size in CSS. Percentage is great for responsive design and easy to maintain, while em offers more design flexibility and control. Ultimately, the choice between the two will depend on your specific needs and the design goals of your website. It is recommended to experiment and see which unit of measurement works best for your particular project.
