readable

Readable is an adjective used to describe text or material that can be easily read and understood by the intended audience. It encompasses legibility—the ease with which a person can discern the written characters—and comprehensibility—the ease of grasping the meaning. In publishing, education, and digital media, readability is a common goal to ensure information is accessible to readers of varying backgrounds and literacy levels.

Several factors influence readability: sentence length, vocabulary difficulty, syntactic complexity, organization, and typography. Good readability typically employs shorter sentences, familiar words, clear structure with headings and lists, and generous white space. Visual design elements such as font size, typeface, line length, color contrast, and margins also affect how easily text can be read, especially on screens.

Readability is often measured using formulas such as the Flesch Reading Ease and the Flesch-Kincaid Grade Level, the Gunning Fog Index, and the SMOG index. These indices estimate difficulty based on sentence length and syllable counts. They provide rough guidance but have limitations and should be used alongside qualitative judgment.

In accessibility work, readability intersects with plain-language principles and information design. Practices include simplifying language, avoiding jargon, providing definitions, using headings and summaries, and offering alternative formats to reach readers with different abilities and devices.

In computing, the term also appears in programming contexts as "readable" data or as a Readable stream in APIs that provide sequential access to data. While not essential to everyday writing, these technical senses share the core idea that information can be read and understood in a straightforward manner.