Free Sentence Counter
Count sentences instantly and see your average sentence length. Free, unlimited, private — ideal for tightening readability.
A sentence counter tells you how many sentences are in a passage by splitting on full stops, question marks, and exclamation points. Humanit’s free sentence counter also reports your average sentence length — a key readability signal — and runs entirely in your browser with nothing uploaded.
How it works
- 1Paste your text. Type or paste your text into the sentence counter above.
- 2See results instantly. The numbers update live as you type — there’s no button to press.
- 3Edit and re-check. Tweak your text and watch the results change in real time.
How sentences are counted
The counter splits your text on sentence-ending punctuation — periods, question marks, and exclamation points — and ignores empty fragments. A block of text with no ending punctuation still counts as one sentence, so short notes are never reported as zero.
Why average sentence length matters
Uniform sentence length is one of the signals AI detectors score on (low “burstiness”). Varied length — mixing short, punchy sentences with longer ones — reads as more human and more engaging. Watching your average and your sentence count helps you spot a passage that has gone flat and monotonous.
Tighten your writing
Most clear writing averages 15–20 words per sentence. If your average climbs much higher, readers lose the thread; break long sentences in two. The live count lets you edit and immediately see the effect.
The abbreviation problem every sentence counter has
Splitting text into sentences is harder than it looks, because a period does not always end one. "Dr. Chen met Prof. Ali at 3 p.m. on Tuesday." is one sentence containing four periods, and a naive counter reports four. Decimals ("$3.5 million"), initials ("J. R. R. Tolkien"), abbreviations (e.g., i.e., etc., U.S., Inc.), and ellipses all do the same thing. This counter treats terminal punctuation as a sentence end when it is followed by whitespace and a capital letter or the end of the text, which handles the ordinary cases correctly. Nothing handles every case — if a document is dense with abbreviations, expect the count to run slightly high, and check the number against a paragraph you can count by eye.
Why sentence variety matters more than the average
Two texts can share an average of 17 words per sentence and read completely differently. One alternates a six-word sentence with a twenty-eight-word one; the other runs seventeen, seventeen, seventeen. The first has rhythm and the second is a metronome — and the second is what unedited AI output usually looks like, which is why "burstiness" is one of the main signals detectors score. If you write a passage and it feels flat despite a sensible average, the fix is almost always to cut one sentence in half and let another run long, rather than to shorten everything.
A quick way to use the number
Paste a section you are unhappy with and look at two things: the average, and whether the sentence count is close to the paragraph count. If a paragraph is one long sentence, it is probably doing too much. If your average is over 25, find the longest sentence and split it at its first "and" or "which" — that single edit usually pulls the whole section back into range, and you can watch it happen live above.
Free, unlimited, and private
The sentence counter is free with no sign-up and no limit on how much text you process. Because it runs entirely in your browser, your text is never sent to a server, stored, or used to train any AI — it never leaves your device. When you’re ready to do more with your writing, Humanit’s AI humanizer and AI detector are one click away.
| Words per sentence | Reads as | Best for |
|---|---|---|
| 8–11 | Very easy, punchy | Ads, UX copy, social |
| 15–20 | Clear and standard | Most writing |
| 21–25 | Denser | Reports, analysis |
| 25+ | Hard to follow | Trim it down |
Frequently asked questions
How does it decide where a sentence ends?
It splits on terminal punctuation — periods, question marks, and exclamation points — and ignores empty fragments, so the count reflects real sentences.
Does it count a line with no period as a sentence?
Yes. A block of text with no ending punctuation is counted as one sentence rather than zero, which matches how people read.
What is a good average sentence length?
For clear, general-audience writing, 15–20 words per sentence is a good target. Varying the length keeps the writing from sounding flat.
Does it handle abbreviations like "Dr." and "e.g." correctly?
Mostly. It treats a period as a sentence end only when whitespace and a capital letter (or the end of the text) follow it, which handles ordinary prose well. Text that is dense with abbreviations or initials may still count slightly high — no sentence splitter is perfect on those.
How many sentences should a paragraph have?
Three to five for most writing, two to four for web and blog copy. The count matters less than whether the paragraph makes a single point — six short sentences on one idea is fine, three on three ideas is not.
Is it free and private?
Yes — free, unlimited, no account, and it runs entirely in your browser so your text is never uploaded.
Do I need an account?
No. There’s no sign-up and no install — open the page and start typing.
Does it work on mobile?
Yes — it works in any modern browser on phone, tablet, or desktop.
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Open the AI HumanizerLast updated: May 2026