Sentence variety analyzer: the rhythm detectors read
AI detectors estimate two things: how predictable each word is (perplexity) and how much that predictability varies across the text (burstiness). Sentence length is the part of burstiness you can see. This tool charts it, sentence by sentence, and gives you a variation score, computed in your browser, without sending the text anywhere.
Reading the chart
Each bar is one sentence, in order; height is its length in words. Human prose usually looks jagged: a 34-word sentence, then a 6-word one, then 18. Model-written text (and text that has been through several rounds of grammar tools) tends to flatten into bars of similar height. The variation score is the coefficient of variation (standard deviation ÷ mean); under about 35% is the range detectors treat as uniform.
How to add variety without adding noise
Cut one long sentence in two where the second half is the point. Follow a complex sentence with a plain declarative. Let a question stand alone. Delete the second of two sentences that say the same thing. Vary openings: not every sentence needs to start with the subject. Read it aloud: where you run out of breath, the reader did too.
Why this matters for false positives
Writers who learned English formally, and anyone drilled on ‘complete, balanced sentences’, produce very regular prose, and detectors misclassify it at higher rates. If your own writing scores as uniform here, the fix is stylistic, not a rewrite of your ideas. Then check the result against the in-app detector, before and after.
Is a high variation score a guarantee against detection?
No. Variation is one signal among several a classifier reads, and every detector differs. It is a reliable way to remove the most common machine-like pattern, not a guarantee, and we never present it as one.
What score should I aim for?
Edited human prose commonly lands between 40% and 70%. Below 25% is very uniform. Above 80% is fine if it still reads naturally.
Does the humanizer change sentence variety?
Yes. Varying rhythm is one of the main things a rewrite does. Paste the output back here to see the difference, or use the in-app score to check the effect directly.