Readability Checker

Several formulas are shown because each weights different things, and agreement between them is more informative than any single number.

Flesch Reading Ease runs 0–100, higher being easier. It weights sentence length and syllables per word:

Flesch–Kincaid Grade converts the same inputs to a US school grade level.

Gunning Fog counts words of three or more syllables specifically, so it is harsher on jargon.

Coleman–Liau uses characters rather than syllables, which makes it more reliable on text where syllable estimation is shaky — technical terms, product names.

Aim for 60–70 for most web content. Below 30, you are writing for specialists whether you meant to or not.

A score tells you there is a problem. The highlighting tells you where it is, which is the part you can act on.

Long sentences are marked above 25 words and flagged harder above 35. Long is not automatically bad — variation in sentence length is what makes prose readable — but three consecutive 40-word sentences will lose people regardless of how good the content is.

Passive voice is marked, not condemned. "The server was restarted" is the right choice when who restarted it is irrelevant or unknown. It becomes a problem when it is the default, because it removes the actor from every sentence and makes writing feel evasive.

Complex words — three or more syllables — are underlined. Many are unavoidable and correct. The question is whether a shorter word would do: "use" for "utilise", "help" for "facilitate", "about" for "approximately".

The formulas are blunt instruments. They count syllables and sentence lengths; they cannot tell whether an idea is clearly explained. A page of short sentences full of unexplained jargon scores well and reads terribly. Use the score to find suspects, then use judgement.