Four styles, four editions, and why the edition repeats every time
The four styles on offer are not evergreen standards; each is a specific, dated edition — APA 7th, MLA 9th, Chicago 17th in its notes-and-bibliography form, and Harvard as set out in Cite Them Right. Manuals get revised, and a finished citation carries no mark of which edition produced it once it is sitting in a reference list. That is why the Citation Formatter names the edition next to every result: it is the one piece of information you cannot recover later if a rule changes underneath you.
The same author list, formatted four different ways
APA and Harvard reduce every given name to initials and attach them to the surname with a comma — Smith, J. MLA and Chicago do the opposite: the first author is written surname-first, and every author after that reverts to natural order, first name before surname. Two styles compress a name; two only reorder the first one.
The four styles also disagree about when a list of authors becomes “et al.” MLA switches at three authors, replacing everyone after the first with the abbreviation. Chicago is far more permissive and only switches beyond ten, listing the first seven. APA lists up to twenty authors in full, joined with an ampersand rather than the word “and,” and only past twenty does it fall back to the first nineteen, an ellipsis, and the final name. Harvard uses the same initials-based name format as APA but joins the list with “and” — the one place the two styles that look most alike actually diverge.
An empty field does not become an error
The reference is assembled only from what you type in. Leave the publisher blank and the citation is built without one — no placeholder, no error — and the result states what it did not have. That line is worth reading before copying, because a field missing silently is indistinguishable from a field that was simply never given.
Capitalisation is a guess about your title, not a rule
APA and Harvard put a title in sentence case; MLA and Chicago put it in headline case. Neither transformation can tell a proper noun from an ordinary word, so a title containing a name or an acronym needs checking by eye either way — there is no way for the conversion to know which words in your title were never supposed to be lowercased.
Entering an organisation as the author
Author parsing looks for a comma to split a surname from initials. Type an organisation’s name with no comma in it and it is treated as a single, indivisible name and passed through unchanged, rather than being torn into a fake surname and initials it was never meant to have.
Why the scope stops where it does
Four source types — book, journal article, web page, chapter in an edited book — and four styles, with no IEEE, Vancouver, AMA, films, datasets, interviews, legislation or social posts. A citation that is subtly wrong is not caught by anyone until the work has already been marked, so covering a source type badly is a worse outcome than leaving it out and saying so plainly.
What it is, and is not, a substitute for
Departments vary their requirements and manuals get revised out from under a generator that was correct when it was written. Treat the result as a draft that saves the typing and gets the structure right, and check it against the guide the work will actually be marked against before submitting anything.