Average sentence length, standard deviation, longest / shortest sentences, and a histogram of sentence lengths.
Use sentence-length analysis to spot monotonous rhythm — long passages of all-similar sentence lengths read as flat. Editors and writing coaches use it to push clients toward more varied syntax.
Sentence-length variety captures something Flesch and SMOG cannot: rhythm. Use it as a stylistic supplement to grade-level formulas.
This tool measures the mean and standard deviation of sentence length across your text.
A high standard deviation usually correlates with more engaging, varied prose — long sentences carry detail, short sentences punch.
Hemingway-style writing keeps average sentences around 12 words. Academic writing often runs 25+.
For most writing, 15–20 words per sentence reads well. Mix short and long for variety — high standard deviation usually correlates with engaging prose.
Strings of same-length sentences read as monotonous, while mixing short and long sentences creates rhythm and keeps readers engaged. A high standard deviation indicates good variety; a very low one suggests your prose may feel flat.
It measures how much your sentence lengths spread around the average. A larger value means you mix short and long sentences, while a value near zero means most sentences are nearly the same length.
Sentences are split on terminal punctuation such as periods, question marks, and exclamation points. Abbreviations, decimals, and ellipses can occasionally cause miscounts, so treat the totals as close estimates rather than exact figures.
Input
Short punch. Then a long, winding sentence that meanders through several thoughts and clauses before landing. Short again.
Output
Mean: 8.7 words, SD: 6.3 — High variety.
Three sentences of 2, 17, and 2 words. The high standard deviation is the signature of engaging, rhythm-aware prose.
% content words vs. function words.
analysisVocabulary variety — type‑token ratio.
analysisTotal + per‑word syllable counts.
analysisHighlight passive sentences in your writing.