Keyword Density Checker

How this tool works and its limitations

Text is cut into words in this browser. Letters and digits make a word, and a hyphen or an apostrophe between two of them stays inside it, so well-known and don't are one word each, as they are in the Word and Character Counter. A comma or period between two digits stays too, so 1,000 and 3.14 are one word. Anything else ends a word: other punctuation, symbols, emoji, slashes and a hyphen with spaces around it. Chinese and Japanese letters count as one word each, and Thai, Lao, Khmer and Myanmar text is split with the browser's own dictionary, using the same code as the counter.

Capital letters are folded with the browser's lowercasing after the text is put in Unicode normal form, so a letter typed with a separate accent equals the single accented letter. The Turkish dotted capital I becomes a plain i, the dotless i stays its own letter, and the German sharp s stays different from ss. Curly apostrophes become straight ones.

A phrase is two or three words with only spaces between them. Each phrase is counted at every position, so phrases overlap, and the lists are sorted by count with ties kept in the order of first appearance. A text is cut into words once, so changing a setting or the target does not repeat that work. Large pastes are processed in short steps with a pause between them, which keeps typing and scrolling responsive, and nothing is stored or sent.

Copy as CSV follows RFC 4180, with comma separators and CRLF line ends. As a safeguard against spreadsheet formulas, any cell that starts with an equals sign, a plus sign, a minus sign or an at sign gets an apostrophe in front of it; phrases here start with a letter or a digit, so the safeguard is rarely needed.

The stop word list has 182 words: a, about, above, after, again, against, all, also, am, an, and, any, are, aren't, as, at, be, because, been, before, being, below, between, both, but, by, can, can't, cannot, could, couldn't, did, didn't, do, does, doesn't, doing, don't, down, during, each, few, for, from, further, had, hadn't, has, hasn't, have, haven't, having, he, he'd, he'll, he's, her, here, here's, hers, herself, him, himself, his, how, how's, i, i'd, i'll, i'm, i've, if, in, into, is, isn't, it, it's, its, itself, just, let's, may, me, might, more, most, must, mustn't, my, myself, no, nor, not, of, off, on, once, only, or, other, ought, our, ours, ourselves, out, over, own, same, shall, shan't, she, she'd, she'll, she's, should, shouldn't, so, some, such, than, that, that's, the, their, theirs, them, themselves, then, there, there's, these, they, they'd, they'll, they're, they've, this, those, through, to, too, under, until, up, very, was, wasn't, we, we'd, we'll, we're, we've, were, weren't, what, what's, when, when's, where, where's, which, while, who, who's, whom, why, why's, will, with, won't, would, wouldn't, you, you'd, you'll, you're, you've, your, yours, yourself, yourselves. These limits are worth knowing:

• The tool describes the text you paste. It does not score ranking potential, and no density it prints is a target to reach or a limit to stay under.
• Words are matched in the exact form typed, with no stemming: shoe, shoes and shoeing are three words, and a target keyword finds only the form you enter.
• The stop word list is English only, so for a text in another language switch the option off, or its common words will crowd the lists. A few listed words, such as will and may, can also be nouns, and switching the option off brings them back.
• A phrase never runs across punctuation, a symbol, an emoji or a line break, so text broken into short lines, such as a hard wrapped email, loses the phrases that straddle each break.
• Web addresses, words joined by a slash and words joined by an en or em dash are split into their parts, so the total can differ a little from the Word and Character Counter, which counts each of those as one word. A hyphen keeps a word whole in both tools, and a dash or hyphen with spaces around it splits in both.
• Chinese and Japanese letters count as one word each, so a phrase of those scripts is two or three letters in a row, not a dictionary word. Such a phrase is always shown with its letters joined, even where the text had a space between two of them, because occurrences with and without the space are counted as one phrase. Thai, Lao, Khmer and Myanmar words come from the dictionary in your browser and can differ between browsers.
• Capital letters are folded without knowing the language: a Turkish capital I becomes an ordinary i rather than a dotless one, and the German sharp s stays different from ss.
• Text larger than 5 MB is not analyzed. In a test in Chromium on a laptop, a 1 MB paste was analyzed in about 0.25 seconds and a 5 MB paste in about 1.1 seconds, including the short wait before work starts, and the page was never blocked for more than 50 milliseconds at a time. A phone is slower, and a text with very many different words can take a little longer than a repetitive one.