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Sentence Counter

Count the number of sentences in any text instantly. Free online sentence counter — accurate period, question mark, and exclamation detection. No signup needed.

How it works

The Sentence Counter counts the number of sentences in a block of text, identifying sentence boundaries at periods (.), exclamation marks (!), and question marks (?). It also calculates the average sentence length in words — a key readability metric.

Sentence length directly affects readability. Long sentences (30+ words) are harder to process and score poorly on readability indexes like Flesch-Kincaid. Most readability guidelines recommend an average sentence length of 15-20 words for general audiences. Short sentences create emphasis and improve scannability in web content.

How to use it: paste any text. The tool counts sentences, calculates average length, shows the shortest and longest sentences, and provides a readability grade estimate. The sentence list view lets you click on a sentence to jump to it for editing.

Readability context: a Flesch-Kincaid Grade Level of 8 means the text is readable by an average 8th grader, which is the standard recommendation for general web content. Technical documentation can be grade 12+, but marketing copy and landing pages should target grade 7-9 for broad accessibility.

SEO note: search engines like Google prioritize pages that users engage with. Content with short, clear sentences tends to have lower bounce rates and higher time-on-page — both indirect ranking signals. Use this tool when editing blog posts, landing pages, and product descriptions to ensure readability before publishing.

Frequently Asked Questions

How does it handle abbreviations like 'Dr.' or 'e.g.' that contain periods?
A built-in abbreviation list prevents common abbreviations (Dr., Mr., Mrs., e.g., i.e., etc., U.S., P.O.) from being treated as sentence endings. The list covers over 200 common abbreviations.
What is a good average sentence length for web content?
15–20 words per sentence is the recommended range for general web audiences. Technical documentation can go to 25–30. Marketing copy and landing pages benefit from 10–15 words for scannability.
How is the Flesch-Kincaid grade level calculated?
FK Grade = 0.39 × (words/sentences) + 11.8 × (syllables/words) − 15.59. It estimates the US school grade level needed to understand the text. Grade 8 is the standard target for general web content.
Does it count questions and exclamations as sentences?
Yes. Sentences ending with ?, !, or . are all counted. Ellipsis (...) is not counted as a sentence ending.