Legibility & Readability

Great typography happens when you arrange text or copy on a page and make it both legible and readable. Although, 'Legibility' and 'Readability' both relate to the ease and clarity with which you read any particular setting of type, but they actually refer to two different concepts. To explore this difference, it is important to understand that legibility is a component of readability. 

Legibility is the measure of how distinguishable individual character to the eye of reader; whereas readability is the measure of how easy it is to read the text overall.

Legibility is related to the design of the typeface and the shape of the glyphs, while readability refers to how the font is arranged, or typeset. Both are important when setting text.

"Legibility" is based on the ease with which one letter can be told from the other. 

"Readability" is the ease with which the eye can absorb the message and move along the line. 

- J. Ben Liberman "Types of Typeface"(1968)  

Harnessing readability and legibility on the web will help you create content that offers a better user experience for your leads and customers.

Readability is a responsibility shared by both copywriter or content writer and the designer. While creating legible text typically lies solely on the designer and developer in digital material.

LEGIBILITY

Legibility refers to how a typeface is designed and how well one individual character can be distinguished from one another. 

Its also important to keep in mind that different typefaces were designed for different uses.

The legibility of a typeface is a product of its design and relates to the ability to distinguish one glyph from another when reading.

Factors contributing to the typeface's legibility are as follows: 

• x-height
• Character width
• Weight
• Design traits
• Stroke contrast
• Counters
• Serifs or lack thereof

In addition, many professionals believe that what you read most, you read best. Therefore, in the U.S., where running text in books, magazines, and newspapers is typically typeset using serif text fonts, readers are most comfortable and familiar with them and therefore find them more legible. By contrast, sans serif fonts may appear more legible to audiences in countries where they are more commonly used.

Keep in mind that not all typefaces are designed to be legible. This is more of a consideration for text designs, where the degree of legibility relates directly to holding the reader’s attention for the length of the copy. Display designs are generally used for fewer words in larger sizes, where the objective is to attract a reader’s eye and to convey a mood, feeling, or message. In this case, legibility might not be of primary consideration.

READABILITY

Readability creates better reading experiences.

Readability is about the reader - the ease with which a reader can successfully decipher, process and make meaning of the text read. 

It is about arranging words or group of words in a way that allows the readers eye to access the content easily and in a way that make sense. Its really an art form that is honed over time as successful combinations are found.

Readability is how the type is arranged(or typeset) and therefore is controlled by the designer.

Factors affecting type's readability are as follows:

• Type size
• Type case
• Line spacing(or leading)
• Tracking
• Kerning
• Alignment
• Line length(or column width)
• Color or contrast

Since these readability factors are chosen by the designer, not inherent to the text, even very legible fonts may lack readability when set in certain ways. In addition, not all factors affecting readability are equally significant.  For example, although generally speaking, smaller type size is harder to read, you may be able to improve a font’s readability by setting it slightly smaller, but with wider line spacing.

So, for a successful business both legibility and readability are equally important. If the legibility of your fonts are crystal clear; but content presentation quality is poor - your customer won't read it. Similarly, if the readability of your copy is compelling and on point; but lost in physically difficult to read typography - your customers can't read it. If readers find it an effort to read and navigate your text, your business can wind up lost for words.

Reference 
https://creativepro.com
https://anchordigital.com.au/

- Rupali Thombare