0Avg words/sentence
0Avg sentences/¶
0Longest (words)
0Shortest (words)
0Over 25 words
Flesch Reading Easen/a
FK grade leveln/a
What this means
Type at least 10 words and one full sentence to get a readability score.
Sentences over 25 words0 flagged
Sentence length is the single biggest lever on readability. Split each one of these and your Flesch-Kincaid grade drops noticeably.
None: every sentence is at or under 25 words.
Sentence Counter
Live Flesch / FK readability · Flags sentences over 25 words · Runs in your browser · no upload
What is a sentence counter (and why length matters)
Count sentences, watch your average sentence length, and get a live readability score (Flesch Reading Ease + Flesch-Kincaid grade) as you write. The counter flags any sentence over 25 words so you can split it before publishing. Everything runs in your browser; your text never leaves your device.
Where a word counter measures how much you've written and a character counter tracks platform limits, a sentence counter tells you how easy your text is to read. Average sentence length is the single biggest lever on readability: trim a long sentence and the Flesch-Kincaid grade drops without changing what you're saying.
- Live sentence count with abbreviation-aware splitting (Mr., Dr., e.g., single initials …)
- Average words per sentence and sentences per paragraph
- Flesch Reading Ease + Flesch-Kincaid grade with a plain-language label
- Flags every sentence over 25 words so you can find and split them
Quick answer
Aim for 15-20 words per sentence on average for web and business writing. Anything over 25 should be either deliberate or split.
Flesch Reading Ease reference
The canonical 7-tier interpretation. The same bands the live readability panel uses, so both pages read from one source and the table never drifts out of sync with the tool.
| Score | Label | Grade level | What it means |
|---|---|---|---|
| 90-100 | Very easy | 5th grade | Conversational; easy for an average 11-year-old. |
| 80-89.9 | Easy | 6th grade | Easy. Conversational English for most consumers. |
| 70-79.9 | Fairly easy | 7th grade | Fairly easy to read. |
| 60-69.9 | Standard | 8th-9th grade | Plain English. Comfortably read by 13-15 year-olds. |
| 50-59.9 | Fairly difficult | 10th-12th grade | Fairly difficult to read. |
| 30-49.9 | Difficult | College | Difficult to read. College-level prose. |
| 0-29.9 | Very difficult | College graduate | Best understood by university graduates. |
Built for sentence-level editing
Three views on the same text: counts, readability, and the specific long-sentence offenders to fix.
Counts
- SentencesBig
- Paragraphs · words · characters
- Avg words / sentence
- Avg sentences / paragraph
Readability
- Flesch Reading Ease0-100
- Flesch-Kincaid gradeUS
- Plain-language band label
- "What this means" line
Long-sentence flagger
- Word threshold>25
- Lists each offender
- Truncates to 180 chars for scan-ability
- All client-side
How to use the sentence counter
Three steps. No sign-up, no setup, nothing to install.
- 1
Paste or type
Drop your draft into the box. Sentence count, averages, and readability update on every keystroke.
- 2
Read the band
The Reading Ease label and FK grade tell you who can follow your text. Most consumer writing targets the Easy-Standard bands (60-89).
- 3
Split the long ones
Scroll the long-sentence list and split anything you can. Watch the Ease score climb back into the green band.
Who built this
Same team behind the Word Counter and the Character Counter. Every counter on this site runs entirely in your browser.
The WordCounters team
Linguists, editors & engineersA small team of writers and engineers shipping privacy-first text tools. Readability is computed with the original Flesch-Kincaid formulas; the 7-tier label table follows Flesch's canonical interpretation.
Frequently asked
Direct answers; mirrored in this page's FAQ JSON-LD so AI answer engines can cite them cleanly.
How does the counter decide where one sentence ends and the next begins?
It splits on sentence-final punctuation: period, exclamation mark, question mark, or ellipsis, followed by whitespace or end-of-text. Common abbreviation periods (Mr., Mrs., Dr., e.g., i.e., single capital initials) are masked first so they don't fragment a sentence. It's a good real-time heuristic, not a parser.
What is a good average sentence length?
For most web and business writing, aim for 15-20 words per sentence on average. Under 10 reads choppy; over 25 starts to lose readers. The counter shows the running average and flags any individual sentence above 25 words so you can split it.
What is the Flesch Reading Ease score?
A 0-100 score where higher numbers mean easier to read. The formula combines average sentence length with average syllables per word: shorter sentences and shorter words push the score up. We translate the number into a plain-language label (Very easy → Very difficult) using the canonical 7-tier interpretation.
What does Flesch-Kincaid grade level mean?
It estimates the US school grade needed to read your text comfortably. A grade of 8 means an eighth-grader (~13 years old) can follow it. Most consumer-facing writing aims for grades 6-9. Technical writing and academic prose run higher.
Why does the counter flag long sentences?
Sentence length is the single biggest lever you have on readability. Splitting a 40-word sentence into two 20-word sentences drops your Flesch-Kincaid grade noticeably without changing what you're saying. The tracker lists each sentence over 25 words so you can find them at a glance.
Is my text uploaded anywhere?
No. The counter runs entirely in your browser. We don't upload, log, or send a single character to any server. Your text is held in your browser's per-tab session storage so a refresh doesn't lose your work, and it clears the moment you close the tab. The page itself is static HTML; the counter is a small client-side script. Closing the tab is the only privacy guarantee you ever need.
Try the rest of the tools
Same brutalist console, same privacy promise. Pick a counter: