See how many sentences you wrote and how long they run.
Sentences are split at full stops, question marks and exclamation marks, with special handling so that common abbreviations such as Mr., Dr., e.g. and single initials do not end a sentence early. Closing quotes and brackets stay with the sentence they belong to.
The report lists every sentence with its word count, plus the average length. Readability guides often suggest keeping most sentences below about 25 words, so the tool highlights how many exceed that.
It recognizes a list of common abbreviations and single capital initials, and does not treat their period as the end of a sentence. Unusual abbreviations can still cause an extra split.
A line without ending punctuation is joined to what follows it. Add a period to a heading if you want it counted separately.
For general web writing, between 14 and 20 words is comfortable. Technical and legal writing runs longer, but sentences past 30 words are hard for most readers.