Readability and Legibility

Readability

Readability is a measure of how easy to read and follow is the written content. Copywriters, content writers, and designers are responsible for assuring good readability for the written content. For example, very complex and long sentences are hard to follow and to understand.

Guidelines to ensure a good readability

1. Avoid fancy words and made-up terms. Also, try to avoid the use of acronyms.
2. Write short sentences and smaller paragraphs.
3. If you target a bigger market, try to write at an 8th grade reading level. For more educated audiences, a 12th grade reading level is more than enough.
4. Start with the conclusion, and elaborate after, but be brief.

Legibility

Are people able to see, distinguish, and recognize the characters and words in your text? Then your written content has good legibility. "Legible" goes back to the Latin word legibilis, meaning "that can be read." Legibility is determined by respecting the visual design, and typography rules, such as good contrast, good tracking, kerning, leading.

Guidelines to ensure a good legibility

1. Use a reasonably large default font size and allow users to change the font size.
2. Have a high contrast between characters and background.
3. Use a clean typeface, and be careful when using handwriting or gothic style: those styles have reduced legibility.

Exercise

Be aware to have a looser letter spacing (tracking) for small type sizes. Look at the below example with different letter spacing for a type size of 16px.

There should be no more 40 to 60 characters per line for body text. For desktop, you can use longer lines up to 120 characters, but you will need to increase the line height.

Use a line height (leading) bigger then the text size, it's safe to apply a ratio between the font size and the line height like this: line-height = font-size X 1.4 (or 1.5).

For body text or long copy of text, it's a good practice to keep the text left-aligned and not centered. This applies for languages such as English.

Be aware of the combination of colored text with colored background, a bad combination will result in low distinction in the text, and would result in very bad accessibility. Colored text should be used mainly to draw attention (headlines, buttons, and links).

Conclusion

Most of the users will read less than 30% of the written content since we are mainly scanning the information and stopping on whatever is interesting to us. Assuring good readability and legibility is a great way to prepare your content for a great experience.