Paragraph counter with the words in every paragraph

No — the page reads both conventions and tells you what each one finds. Text with blank lines between blocks is grouped on those blanks; text with one paragraph per line and no blanks at all is counted a line at a time. The automatic setting uses blank lines whenever the text contains any, which is the right guess for anything written in plain text, Markdown or an email. When it guesses wrong, the menu lets you force either rule, and the two figures stay side by side so you can see what the choice cost.

Because a word processor counts every press of Enter as a paragraph, including the empty ones. In Word, Google Docs and Pages, a paragraph is a formatting unit rather than a unit of prose: each heading is a paragraph, each bullet is a paragraph, each empty line you left for spacing is a paragraph of its own, and so is the caption under a picture. This page counts blocks of prose and ignores blank lines entirely, so a document that Word describes as 84 paragraphs commonly arrives here as 31.

Yes, if it sits on a line of its own with blank lines around it, because in plain text there is nothing to tell a heading apart from a very short paragraph. Formatting is what marks a heading in a document, and formatting is exactly what is lost when you copy text into a plain box. Headings show up in the list as one-sentence paragraphs of three or four words, which makes them easy to spot — and if they are distorting your average, deleting them before you paste takes a moment.

Online, most editors aim for 40 to 100 words — three or four sentences — and treat anything past 150 as a wall. Print is more generous, and academic writing more generous still: a journal paragraph of 200 words carrying one argument is perfectly normal, while the same paragraph on a phone screen fills the entire display and gets skipped. There is no rule to enforce, which is why the flag is a number you set rather than a fixed limit. The useful signal is not the average but the spread — a piece where every paragraph is within ten words of every other reads as flat however long they are.

No, they are emphasis — and emphasis stops working when it is everywhere. A single sentence standing alone is the oldest way to make a reader slow down, and copywriters use it deliberately at the turn of an argument. The page marks them because the tic is invisible from inside the draft: it is very common to write six of them in a row without noticing, at which point the emphasis is gone and the piece reads as a list of assertions. The count and the share are reported at the foot of the list so you can judge the proportion rather than the individual case.

In HTML a paragraph is whatever sits inside a pair of paragraph tags, and blank lines have nothing to do with it. That is why a web page whose source is written as one enormous unbroken line can still display twelve neat paragraphs, and why text pasted out of a web page sometimes arrives with the paragraph breaks intact and sometimes as a single block — it depends on how the page marked them up. Plain text has no tags, so the blank line is the only paragraph mark it owns, which is precisely why this page supports two rules instead of one.

Yes, under the blank-line rule: consecutive lines with no blank between them are treated as a single paragraph, and the list marks it with how many lines it spans. This matters for text pasted out of a PDF, where a paragraph arrives as six or seven hard-wrapped lines. Under the one-paragraph-per-line rule those same six lines count as six paragraphs, which is the honest answer to what that rule asks — if that is what you are seeing, the automatic setting has picked the wrong convention and switching it fixes the count.