Methodology
Every number on socialwordcounter.com comes from a documented, reproducible rule.
Counting
Words, sentences and graphemes are segmented with the browser's Intl.Segmenter. URLs, emails, @handles and #hashtags are masked before segmentation so each counts as one word. Sentence segments ending in a known abbreviation are merged into the next sentence.
Readability
Readability uses the Flesch Reading Ease and Flesch-Kincaid Grade Level formulas, computed from average sentence length and average syllables per word. The consensus grade is the rounded grade level.
Platform limits
Each platform's limit and counting rule is stored in one place. X applies its weighted rules — URLs count as 23 characters and CJK characters and emoji count as two — while other platforms count characters as typed.