No. Everything is counted inside your browser. Your text is never sent to or stored on a server.

Runs of letters and digits separated by whitespace count as one word each. Japanese characters (hiragana, katakana and kanji) count as one word per character, the same approach word processors use.

Each emoji counts as one character (surrogate pairs are handled correctly). The byte count still shows the real UTF-8 size.

Word count divided by 200 words per minute, a common average for silent reading. Treat it as a rough estimate.

Text inside tables is counted (each cell becomes its own line), and so is text inside text boxes. Chart values and labels, text inside images, SmartArt, headers and footers, footnotes and comments are not counted — Word stores those outside the document body.