Readability Score Checker

Six. Flesch Reading Ease gives a 0 to 100 ease score, and Flesch-Kincaid, Gunning Fog, Coleman-Liau, Automated Readability Index and SMOG each estimate the US school grade needed. All share one set of word, sentence and syllable counts.

Each formula weighs different signals. Coleman-Liau and ARI count letters per word, Gunning Fog and SMOG count words of three or more syllables, and Flesch-Kincaid counts syllables per word. A text heavy in long but common words can split them by several grades.

For Gunning Fog and SMOG, a complex word is any word the syllable heuristic estimates at three or more syllables. The Text statistics row shows the running count so you can see what is driving those two indices up.

It names the US school grade that should read the text on a first pass. A grade of 8 means a typical eighth grader could follow it. Unlike Reading Ease, a lower number here means easier reading.

With a vowel-group heuristic: each word is lowercased, runs of vowels are counted, and a silent trailing e is dropped. It is fast rather than a dictionary lookup, so irregular words can be off by one and slightly shift every formula.

Yes. Reading Ease is not clamped, so plain short sentences can exceed 100 while dense, jargon-filled prose can fall below zero. The grade indices can likewise run past grade 16 for very difficult text.

No single one is definitive. Treat them as a panel: if most cluster around the same grade, that is your reading level. When they scatter, the outlier usually reveals whether long words or long sentences are the real problem.

Less so. SMOG was designed for longer passages of about 30 sentences, so on a sentence or two its square-root math is jumpy. For short snippets, lean on Flesch-Kincaid and Coleman-Liau instead.

Yes. Every formula runs in your browser and nothing you paste is uploaded, logged or stored.