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APA vs MLA vs Chicago vs Harvard.

Four styles, tied to four specific editions: APA 7th (2020), MLA 9th (2021), Chicago 18th (2024) — and Harvard, which is not tied to any single edition at all, because no one body governs it. The ledger below compares them element by element; further down, the same book, journal article and web page are cited correctly, four ways.

Updated 25 Jul 2026 By Amit Jain 9 min read 5 sources Free tool

4Styles compared, side by side

2024³Newest edition here — Chicago, 18th

1⁴Of the four with no official body — Harvard

12Formatting elements in the ledger

Every edition and date above is checked against the publisher or governing body itself — see the sources ledger.

01 — The Four, At a Glance

Same job, four traditions.

APA, the Publication Manual of the American Psychological Association, is now in its 7th edition (2020), governed by the APA itself, and dominant across the social and behavioural sciences, education and nursing¹.

MLA, the MLA Handbook, is in its 9th edition (April 2021), governed by the Modern Language Association, and standard through the humanities, literature and language studies².

Chicago, The Chicago Manual of Style, reached its 18th edition on 19 September 2024, governed by the University of Chicago Press. It runs two parallel systems — notes-and-bibliography, favoured in history and the arts, and author-date, favoured in the sciences and social sciences³.

Harvard is different in kind, not just in rules: it is a family of author-date conventions with no single manual and no governing body. Each institution publishes its own variant, so the rows below show one common convention — always confirm the version your own department actually wants⁴.

02 — The Reference Ledger

Twelve elements, compared.

Search across all four columns, or filter to one category. Click a column heading to sort.

Citation style comparison: APA, MLA, Chicago, Harvard

Edition covered hereBasics	7th ed. (2020)	9th ed. (2021)	18th ed. (2024)	No fixed edition
Governing bodyBasics	American Psychological Association	Modern Language Association	University of Chicago Press	None — institution-specific
In-text citationBasics	(Author, Year, p. X)	(Author page)	(Author Year, page)	(Author Year, p. X)
Reference-list titleBasics	References	Works Cited	Bibliography / References	Reference List
Two authorsAuthors	Author, A., & Author, B.	Author, A., and B. Author.	Author, A., and B. Author.	Author, A. and Author, B.
Three or more authorsAuthors	First author et al. (in text, from the first citation)	First author et al.	First author et al. (reference-list threshold varies)	First author et al. (threshold varies by institution)
Book title stylingTitles	Sentence case, italic	Title Case, italic	Title Case, italic	Sentence case, italic
Journal article titleTitles	Sentence case, no quotes	Title Case, in quotes	Title Case, in quotes	Sentence case, in quotes
Journal name, volume & issueTitles	Italic Journal, Vol(Issue)	Italic Journal, vol. #, no. #	Italic Journal vol, no. issue	Italic Journal, Vol(Issue)
DOI / URL formatFormat details	https://doi.org/… (no closing period)	DOI preferred; https:// often dropped	https://doi.org/…	DOI, or “Available at:” URL
Access-date requirementFormat details	Usually not required with a DOI; used for changing pages	Optional/supplemental	Recommended if no post/modified date exists	Commonly required for web sources
Place of publication (books)Format details	Not required	Not a core element	No longer required — new in 18th ed.³	Often still required

Method: static reference data, checked against the sources below on 25 Jul 2026; the controls only search, filter and sort what is already on the page.

03 — Worked Examples

The same source, cited four ways.

Three real, checkable records — a journal article, a style manual itself, and a web page — formatted correctly in each style.

Journal article

Watson & Crick, Nature, 1953

Vol. 171, issue 4356, pp. 737–738. DOI 10.1038/171737a0.⁵

APAWatson, J. D., & Crick, F. H. C. (1953). Molecular structure of nucleic acids: A structure for deoxyribose nucleic acid. Nature, 171(4356), 737–738. https://doi.org/10.1038/171737a0

MLAWatson, J. D., and F. H. C. Crick. “Molecular Structure of Nucleic Acids: A Structure for Deoxyribose Nucleic Acid.” Nature, vol. 171, no. 4356, 1953, pp. 737–738. https://doi.org/10.1038/171737a0.

Chicago (author-date)Watson, J. D., and F. H. C. Crick. 1953. “Molecular Structure of Nucleic Acids: A Structure for Deoxyribose Nucleic Acid.” Nature 171 (4356): 737–738. https://doi.org/10.1038/171737a0.

HarvardWatson, J.D. and Crick, F.H.C. (1953) ‘Molecular structure of nucleic acids: a structure for deoxyribose nucleic acid’, Nature, 171(4356), pp. 737–738. Available at: https://doi.org/10.1038/171737a0 (Accessed: 25 July 2026).

Book

The Chicago Manual of Style, 18th ed.

University of Chicago Press, 2024. Cited here for one reason: its own place-of-publication rule just changed.³

APAThe Chicago manual of style (18th ed.). (2024). University of Chicago Press.

MLAThe Chicago Manual of Style. 18th ed., University of Chicago Press, 2024.

Chicago (author-date)University of Chicago Press. 2024. The Chicago Manual of Style. 18th ed. University of Chicago Press. — no place of publication, per the 18th edition’s own new rule.

HarvardUniversity of Chicago Press (2024) The Chicago manual of style. 18th edn. Chicago, IL: University of Chicago Press. — note Harvard conventions typically still ask for the place.

Web page

MLA Style Center, “What’s New in the Ninth Edition”

style.mla.org, published April 2021.²

APAModern Language Association. (2021, April). What’s new in the ninth edition of the MLA handbook. MLA Style Center. https://style.mla.org/ninth-edition-whats-new/

MLA“What’s New in the Ninth Edition of the MLA Handbook.” MLA Style Center, Modern Language Association, Apr. 2021, style.mla.org/ninth-edition-whats-new/.

Chicago (author-date)Modern Language Association. 2021. “What’s New in the Ninth Edition of the MLA Handbook.” MLA Style Center. April 2021. https://style.mla.org/ninth-edition-whats-new/.

HarvardModern Language Association (2021) What’s new in the ninth edition of the MLA handbook. Available at: https://style.mla.org/ninth-edition-whats-new/ (Accessed: 25 July 2026).

04 — Which Should I Use?

The instruction always wins.

You’ve been told which style to use. Use that one, exactly as your department or journal specifies — over anything on this page.
No instruction, sciences or social sciences. APA is the safe default; Chicago author-date is a common alternative.
No instruction, humanities or literature. MLA is the safe default.
No instruction, history or much trade publishing. Chicago notes-and-bibliography.
Told to use “Harvard.” Find your own institution’s written guide before formatting a single reference — the name alone doesn’t specify the rules.

One habit that prevents most errors: pick the edition once, keep a note of which one, and apply it consistently through the whole piece. Mixing rules from two editions of the same style is a common, entirely avoidable mistake.

05 — FAQ

Real questions, short answers.

Which citation style should I use?

Whichever your instructor, department or target journal specifies — that instruction always wins. Absent one, APA suits sciences and social sciences, MLA suits humanities and literature, Chicago suits history and much publishing, and Harvard is common in UK and Australian universities.

Do I need to include an access date?

It depends on the style. APA and Chicago mainly want one for undated or frequently-changing pages; MLA treats it as optional/supplemental for the same cases; Harvard commonly requires one for web sources, though this varies by institution.

What changed in the newest edition of each style?

Most visibly: Chicago's 18th edition (September 2024) dropped the requirement to state a book's place of publication — APA (7th, 2020) and MLA (9th, 2021) are themselves the current editions, each with their own smaller updates from the prior edition.

Is "Harvard" the same everywhere?

No — this is the single most important thing to know about it. Harvard has no official manual or governing body; it is a family of author-date conventions that each university publishes its own version of. Always check your own institution's guide.

Do I cite the DOI or the URL?

The DOI, formatted as a full https://doi.org/ link, whenever one exists — across APA, MLA and Chicago alike. A DOI is permanent; a URL can break. Use a plain URL only when no DOI has been assigned.

Does this page format my citations for me?

Not yet on this page — it compares the rules and shows worked examples so you can format your own correctly. The source-check tool on the AFG Write home page reads a DOI's metadata and returns a formatted citation.

06 — Sources

Where every edition and date above comes from

American Psychological Association, Publication Manual of the American Psychological Association, 7th edition (2020); official guidance at apastyle.apa.org.apastyle.apa.org · accessed 25 Jul 2026
Modern Language Association, MLA Handbook, 9th edition (published April 2021); MLA Style Center, “What’s New in the Ninth Edition of the MLA Handbook.”style.mla.org · accessed 25 Jul 2026
University of Chicago Press, The Chicago Manual of Style, 18th edition, released 19 September 2024; publisher listing and CMOS Shop Talk announcement (16 Apr 2024) confirming the dropped place-of-publication requirement for books.press.uchicago.edu & cmosshoptalk.com · accessed 25 Jul 2026
Representative institutional Harvard-style guides illustrating the lack of a single authority: University of York Library, “Harvard”; the Open University, “Quick Guide to Harvard Referencing (Cite Them Right).”subjectguides.york.ac.uk & university.open.ac.uk · accessed 25 Jul 2026
Nature (Springer Nature), citation metadata for Watson, J. D., and Crick, F. H. C., “Molecular Structure of Nucleic Acids,” Nature 171 (1953): 737–738.nature.com/articles/171737a0 · accessed 25 Jul 2026

About this page: every edition, release date and governing body above is checked against the publisher or association itself. The Harvard row shows one common convention, not a universal rule — the sources ledger names guides that themselves say as much. Where a rule could not be verified against a named source, it was left out rather than guessed.

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