Readability Checker

What the score measures

Flesch Reading Ease uses two inputs and nothing else:

206.835 − 1.015 × (words ÷ sentences) − 84.6 × (syllables ÷ words)

Long sentences push it down. Long words push it down harder. That's the whole model, which is both its strength, it's objective and instant, and its limitation.

Reading the number

Score	Level	Typical of
90–100	Very easy	Children's books
80–90	Easy	Conversational writing
70–80	Fairly easy	Popular fiction, good plain English
60–70	Standard	Newspapers, most web writing
50–60	Fairly difficult	Quality journalism, trade press
30–50	Difficult	Academic writing, technical documentation
Below 30	Very difficult	Legal contracts, research papers

60–70 is the sensible default for anything aimed at a general audience. That's roughly an eighth-grade reading level, and it is not a low bar, it's the level at which people read comfortably rather than effortfully, including people who are tired, distracted, reading on a phone, or reading in a second language.

A low score is not automatically bad

A contract, a research paper or a technical specification should score low. Precision costs readability, and in those contexts precision wins. Readers of a journal article expect and can handle dense prose.

The score becomes a problem when it's lower than your audience expects. A privacy policy scoring 25 is a real failure, because the people it exists to inform can't read it. A landing page scoring 40 is losing readers who had a choice.

How to actually raise it

Split long sentences. This is the highest-leverage change by a wide margin. Any sentence over about 25 words is usually two sentences that haven't been separated yet. Look for "and", "but" and semicolons as the natural break points.

Choose shorter words where they mean the same thing. "Use" for "utilise", "help" for "facilitate", "about" for "approximately", "buy" for "purchase", "start" for "commence". Not because long words are wrong, but because the short one is usually clearer and there's no cost.

Cut throat-clearing. "It is important to note that" is six words that carry no information. "In order to" is "to".

Prefer verbs to noun phrases. "We made a decision" → "we decided". "Give consideration to" → "consider". This shortens sentences and makes them more direct at the same time.

Use the active voice by default. "The committee approved the plan" is shorter and clearer than "the plan was approved by the committee". The passive has real uses, when the actor is unknown or irrelevant, but it's usually a habit rather than a choice.

What the score can't see

This is the important caveat. Flesch measures sentence and word length, so it can be gamed and it can be wrong:

• Short and meaningless scores well. "The thing did the thing to the thing" is very readable and says nothing.
• Jargon in short words is invisible to it. "We need to align on the ask before we socialise the deck" scores beautifully.
• It ignores structure. Headings, paragraphs, lists and ordering affect comprehension enormously and don't appear in the formula.
• It ignores whether you're right. Obviously, but worth saying.

Use it as a smoke alarm, not a grade. A bad score reliably means something is wrong. A good score means nothing is obviously wrong with your sentence lengths.

Why the longest sentences are listed

Because that's where the fixable problems concentrate. Improving a document's score is almost always a matter of finding the five worst sentences and splitting them, far more effective than trying to shave a syllable off every word.