Count every sentence in your text and analyse sentence length in real time. See the total sentence count, average words per sentence, and a live breakdown highlighting your shortest and longest sentences — ideal for editing essays, blog posts, and readability checks.
Sentences are detected by ending punctuation (. ! ?). Counts update live as you type.
Type or paste text above to see the sentence breakdown.
Frequently Asked Questions
What is a Sentence Counter?
A Sentence Counter detects and counts every sentence in a piece of text, then analyses how long each one is. It shows the total sentence count, average sentence length, and highlights the shortest and longest sentences so you can review readability at a glance.
How are sentences detected?
Sentences are split on ending punctuation — full stops (.), question marks (?), and exclamation marks (!). Text without any ending punctuation is treated as a single sentence if it contains content. Abbreviations such as Dr. or e.g. may occasionally be split incorrectly; review the breakdown if precision matters.
How is average sentence length calculated?
Average sentence length is the total word count divided by the number of sentences, rounded to one decimal place. For example, 30 words across 3 sentences gives an average of 10.0 words per sentence.
Why does the breakdown highlight certain sentences?
Sentences tied for the shortest word count are highlighted in green. Sentences tied for the longest word count are highlighted in blue. This makes it easy to spot sentences that may be too terse or too complex during editing.
Can I use this to improve my writing?
Yes. Varying sentence length improves readability. Most plain-language guides recommend an average of 15–20 words per sentence. Use the breakdown to find run-on sentences or choppy fragments, then edit accordingly. For a broader overview, try the Word Counter.
Is my text stored or sent anywhere?
No. All analysis runs entirely in your browser. Your text never leaves your device and is not stored on any server.
How is this different from the Word Counter?
The Word Counter gives a broad overview — words, characters, paragraphs, and reading time. The Sentence Counter focuses specifically on sentence detection and length analysis with a per-sentence breakdown.
Is this tool free and does it work on mobile?
Yes on both counts. The Sentence Counter on draft21 is completely free with no account or sign-up required and works on phones, tablets, and desktops.