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Writing · Readability

Sentence Length Analyzer

Paste text to see your average sentence length, the longest and shortest sentences, and how the lengths are spread.

Try an example — tap to load
5
Sentences
14.6
Avg words / sentence
27
Longest (words)
Sentence-length distribution

How many sentences fall in each word-count band. 73 words across 5 sentences, averaging 14.6 words each.

Longest sentence — 27 words

When every sentence runs the same length, prose turns flat and readers drift, so mix punchy short lines with longer, flowing ones for a more engaging pace.

A sentence length analyzer splits your text on “.”, “!”, and “?”, then counts the words in each sentence to report the average, the longest and shortest, and a distribution. Averages under about 20 words read easily; long, unbroken sentences are the usual culprit when a draft feels dense or hard to follow.

Why sentence length matters

Sentence length is one of the strongest signals of how hard a text is to read — it feeds directly into readability formulas like Flesch–Kincaid and Gunning Fog. Long sentences pack in more clauses, so the reader has to hold more in mind before reaching the point. That is fine occasionally, but a whole paragraph of 30-word sentences quickly tires a reader. This tool surfaces the pattern: the average tells you the overall pace, while the longest sentence is often the one worth splitting.

How it measures

There is no formula — just a deterministic count. The text is split into sentences wherever a period, exclamation mark, or question mark appears, and blank fragments are dropped. Each sentence is then split on spaces to count its words. From those counts the tool derives the average (to one decimal), the longest and shortest sentence, and a histogram that buckets sentences into 1–5, 6–10, 11–15, 16–20, 21–25, and 26+ word bands.

  1. 1
    Paste your text. Drop in a paragraph, an essay, or a full draft — the analysis updates as you edit.
  2. 2
    Split into sentences. The text is divided at every “.”, “!”, and “?”. “Vary your rhythm. Then read it aloud.” becomes two sentences.
  3. 3
    Count words per sentence. Each sentence is split on spaces. “A short sentence lands hard.” is 5 words; a clause-heavy sentence may run past 25.
  4. 4
    Read the average. Total words ÷ sentence count. Five sentences totalling 73 words average 14.6 words each — comfortably readable.
  5. 5
    Fix the outliers. Open the longest-sentence panel and the 26+ band. Break the worst offenders into two, and add a short sentence for contrast.

Rough sentence-length guide

A commonly cited readability guideline for average sentence length. Treat it as a signal, not a rule.

Average words / sentenceReads as
Under 14Easy — clear and quick to follow
14–20Average — the sweet spot for most prose
21–29Fairly hard — dense, watch for run-ons
30 or moreHard — likely needs splitting

Vary your length — long is not bad

A low average is not automatically better. Prose where every sentence is the same length reads as flat and mechanical, whatever that length is. The best writing mixes a punchy short sentence against a longer, flowing one — the distribution chart is there to show whether you actually do that or whether your sentences all cluster in one band. A single long sentence is often the clearest way to develop a complex idea; the problem is only when long sentences pile up with no relief. Aim for a comfortable average, then deliberately vary the rhythm around it.

What is a good average sentence length?
For general and academic prose, an average of about 14–20 words per sentence reads comfortably. Under 14 feels crisp and simple; averages above 25 start to feel dense. These are guidelines, not targets — the right length depends on your audience.
How are sentences detected?
The text is split wherever a period, exclamation mark, or question mark appears, and empty fragments are ignored. It is a simple rule, so abbreviations like “e.g.” or “Dr.” and decimals like “3.5” can be miscounted as sentence breaks.
How is average sentence length calculated?
It is the total number of words divided by the number of sentences, rounded to one decimal place. For example, 73 words across 5 sentences gives an average of 14.6 words per sentence.
How are words counted within a sentence?
Each sentence is split on spaces, and every non-empty chunk counts as one word. Hyphenated terms like “well-known” count as a single word, and numbers count too.
Should I aim for the shortest possible sentences?
No. Uniformly short sentences read as choppy and monotonous, just as uniformly long ones read as dense. Good writing varies length — the distribution chart shows whether your sentences are spread across bands or bunched in one.
What does the distribution chart show?
It buckets your sentences into word-count bands — 1–5, 6–10, 11–15, 16–20, 21–25, and 26+ — and shows how many sentences land in each. A healthy mix spans several bands; a tall single bar means your sentences are all a similar length.