What counts as a "word" for the threshold?

Words are sequences of characters separated by whitespace. Punctuation attached to a word (e.g., commas, periods) is counted as part of that word token, matching everyday word-count conventions.

How are sentence boundaries detected?

The tool splits on terminal punctuation (., !, ?) followed by whitespace or the end of the text. It handles common abbreviations reasonably well, though edge cases like "e.g." or "Dr." may occasionally cause an early split.

What threshold should I use?

Most plain-language guides recommend keeping sentences under 20–25 words for general readers. Legal or academic writing may tolerate up to 35 words. Journalism typically aims for 15–20 words.

Is my text stored or sent anywhere?

No. All processing happens entirely in your browser using JavaScript. Nothing is transmitted to any server.

Can I adjust the threshold after highlighting?

Yes. Move the slider and click "Highlight" again — or enable auto-highlight so the view updates as you drag.

Long Sentence Highlighter

Paste your text and instantly highlight every sentence that exceeds your chosen word-count limit.

Input Text

Word threshold 25 words

5 60

Auto-highlight as I type

Statistics

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Total sentences

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Long sentences

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Total words

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Avg words/sentence

Highlighted Output

Over threshold Within limit

Your highlighted text will appear here.

Summary

The Long Sentence Highlighter scans your pasted text and visually marks every sentence whose word count exceeds a threshold you choose. Shorter sentences are left untouched so you can see at a glance which parts of your writing need to be broken up. Adjust the slider and the highlights update instantly — no page reload required.

How it works

Paste or type your text into the input area.
Set the word-count threshold using the slider (default: 25 words).
Click "Highlight" to analyze the text.
Sentences over the threshold are highlighted in amber; others stay plain.
Edit your text and click "Highlight" again to re-check.
Use "Clear" to reset everything and start fresh.

Use cases

Improve readability by spotting run-on sentences before publishing.
Simplify academic or legal writing for a general audience.
Check blog posts and articles against plain-language guidelines.
Review student essays for overly complex sentence structure.
Prepare speeches and scripts for natural spoken delivery.
Audit marketing copy to keep messaging punchy and clear.

Frequently Asked Questions

Last updated: 2026-05-23 · Reviewed by Nham Vu