Readability is how easily someone can read a piece of writing and understand it the first time through. It depends on the words you choose, how long your sentences run, how the page is laid out and how well the text matches what the reader already knows.
How readability works
Two things are at work. The first is the language itself: short, familiar words and sentences that carry one idea each are quicker to process than long chains of clauses full of abstract nouns. “We will review your application within five working days” is easier than “Applications are subject to a review process, the duration of which is typically five working days.”
The second is the page. Online, most people scan before they read. Clear subheadings, short paragraphs, lists where the content really is a list and plenty of white space let a reader find the part they came for. A wall of text with perfect sentences can still be hard work.
Readability formulas try to put a number on the first part. Flesch Reading Ease, Flesch-Kincaid Grade Level, Gunning Fog and SMOG all count things like syllables per word and words per sentence. They are quick and consistent, but they cannot tell whether your argument makes sense, whether a term is familiar to your audience or whether the layout helps. Treat the score as a prompt to look again, not a verdict.
Why it matters
A useful UK benchmark comes from government. GOV.UK’s content guidance aims for a reading age of about nine, on the basis that even expert readers prefer plain language when they are busy, stressed or reading on a phone. Specialists do not resent clarity; they resent having to work out what you mean.
For a business, readability shows up in enquiries. If a visitor cannot quickly tell what you do, who it is for and what happens next, they go back to the search results and try someone else. Clear copy also helps accessibility: people with dyslexia, people reading in a second language and people using screen readers all benefit, which supports your duties under the Equality Act 2010 and the aims of WCAG.
Google does not rank pages on a readability score as such. What it does reward is content that satisfies the searcher, and readable pages tend to do that better. Clear, self-contained sentences are also easier for search features and AI answer tools to quote accurately.
Common mistakes
- Writing for colleagues rather than customers, so internal jargon and acronyms go unexplained.
- Opening with background and history, and only reaching the point in the fourth paragraph.
- Treating a green light in a plugin as proof the page is clear.
- Over-correcting into choppy, childish copy that drops the precise terms a technical buyer searches for.
- Long paragraphs on mobile, where four lines on a laptop become twelve on a phone.
- Passive constructions that hide who does what, such as “a quote will be provided” instead of “I will send you a quote”.
How to act on it
Start with your most important pages: the homepage, main service pages and anything that leads to an enquiry or sale. Read each one aloud. Wherever you stumble, run out of breath or have to reread, rewrite that sentence.
Then work through a simple routine. Put the answer or the main point first. Cut sentences that run past about 25 words into two. Replace abstract nouns with verbs (“decide” rather than “make a decision”). Explain or remove every acronym. Break up paragraphs longer than four sentences and add subheadings that say what each section contains. Following plain English principles covers most of this.
A free readability and keyword density checker will flag long sentences and dense passages so you know where to look. The best test is still a real customer: ask one to read the page and tell you what you offer and what they would do next. If they cannot, the copy needs work whatever the score says. Rewriting key pages this way is a regular part of my content SEO and strategy work.