Sentence Counter: Free Online Tool
Counts
FREE TOOL · NO SIGN-UP
This sentence counter shows how many sentences are in your text, how many words they contain on average, and which ones run long. It also counts questions and exclamations, and lists every sentence with its word count so you can spot the ones that need trimming. Writers, students, editors and SEOs use it to keep content clear and easy to follow. Paste your text and the counts appear instantly, all inside your browser, so your writing stays private.
How to Use the Sentence Counter
One box, live results, no settings.
Step 1: Enter or paste your input
Paste an essay, blog post, email, script or any other text into the box. Formatting does not matter, since line breaks and extra spaces are ignored when sentences are split. Clear empties the box.
Step 2: Read the counts
The results update as you type:
- Sentences, the headline number.
- Words in the whole text.
- Avg. words / sentence, the key readability signal.
- Long sentences (25+ words), flagged as a warning when there are any.
- Questions and Exclamations, counted from question marks and exclamation marks.
A table underneath lists up to 200 sentences with their number, text and word count.
Step 3: Apply the result
Look at the long sentence count first. Find those sentences in the table, then split them, cut filler words or turn a list buried in the sentence into bullet points. Paste the revised text back in and check the average again.
How Sentence Boundaries Are Detected
The sentence counter ends a sentence at a full stop, question mark, exclamation mark or ellipsis. If a closing quote, bracket or parenthesis follows the punctuation, it stays with that sentence. Any text left at the end without punctuation still counts as a final sentence, so an unfinished draft is counted correctly.
Before splitting, the tool collapses line breaks and repeated spaces into single spaces. That means a sentence that wraps across several lines still counts as one, and a heading without a full stop joins the next sentence. Fragments that contain no letters or numbers, like a lone “…” are ignored.
This punctuation-based approach is fast and predictable, and it matches how most readability tools count. It does not try to understand grammar, so it will not split a run-on sentence joined with commas, and it treats some abbreviations as sentence endings. The next sections explain what to watch for.
Word counts use the same method as our Word Counter, so totals match.
Average Sentence Length and Readability
Average sentence length is one of the strongest predictors of how easy text is to read. Formulas like Flesch Reading Ease and Flesch-Kincaid Grade Level use it directly, alongside syllables per word.
Rough guide for words per sentence:
| Average | How it reads |
|---|---|
| Under 15 | Very easy; good for web, mobile and general audiences |
| 15 to 20 | Clear and standard for most blogs, news and business writing |
| 20 to 25 | Getting dense; fine for expert or academic readers |
| Over 25 | Hard to follow for most readers |
The 25-word flag in this tool is a practical warning line. A few long sentences are fine, but if many of your sentences pass it, readers will need to reread to keep track.
For a full score, paste the same text into the Readability Checker. If the grade level is high, the sentence table here shows you exactly which sentences to fix first.
Abbreviations, Decimals and Edge Cases
Because sentences are split on punctuation, a few patterns can inflate the count:
- Abbreviations such as “Dr.”, “e.g.”, “U.S.” and “etc.” end with a full stop, so the counter may split there.
- Decimals and versions like “3.5” or “v2.1” can split at the point.
- URLs and file names with dots, like example.com or report.pdf, can split too.
- Ellipses used mid-sentence end a sentence here.
- Missing punctuation. Headings, list items and captions without a full stop merge with the next sentence.
If an exact count matters, for example for an assignment, scan the table for very short “sentences” like “Dr” or “5 percent of users” and adjust. For drafts, the effect is usually small and the average is still a reliable guide.
Varying Sentence Length for Better Flow
Average length is only half the picture. Text where every sentence is the same length sounds flat, even when the average is good. Mixing short, medium and long sentences creates rhythm and keeps attention.
Try this pattern: a medium sentence to set up a point, a longer one to explain it, and a short one to land it. Short sentences work well for emphasis and transitions. Longer ones suit explanation, as long as they have one clear idea.
Use the table to check variety. If every sentence shows 18 to 20 words, rewrite a few: split one, combine two short related ones, or cut a sentence down to five words for impact. Reading the text out loud also helps. Wherever you run out of breath, the sentence is probably too long.
Key Features of Our Sentence Counter
- Free with no signup. Check as much text as you want.
- Six counts. Sentences, words, average length, long sentences, questions and exclamations.
- Sentence table. Every sentence (up to 200) with its word count.
- Long sentence warning at 25 words or more.
- Private and instant. Runs in your browser and updates as you type.
Who Uses a Sentence Counter
- Students meeting sentence requirements and keeping essays readable.
- Bloggers and SEO writers aiming for easy reading on mobile.
- Editors finding the longest sentences in a draft quickly.
- ESL learners and teachers practicing shorter, clearer sentences.
- UX and technical writers keeping instructions short and direct.
Pro Tips and Mistakes to Avoid
Checklist of best practices
- Aim for an average of 15 to 20 words for general readers.
- Fix any sentence over 30 words first.
- Put one idea in each sentence.
- Vary length on purpose.
- Recheck after editing to confirm the average dropped.
Common mistakes and quick fixes
- Count looks too high. Abbreviations or decimals are splitting sentences. Check the table for fragments.
- Count looks too low. Headings or list items without punctuation merged into the next sentence.
- Chasing a perfect average. A good average with ten 40-word sentences is still hard to read. Look at the long sentence count.
- Cutting meaning. Shorter is better only if the sentence still says what you need.
Write Sentences Readers Finish
Paste your text above to find long sentences and check your average. Then score it with the Readability Checker, check structure with the Paragraph Counter, and count syllables with the Syllable Counter. See every free tool in the FHSEO Hub tools directory.