APA vs MLA vs Chicago: Which Citation Style Should You Use?

APA, MLA and Chicago are the three citation styles you will meet in almost all academic writing. They exist because different fields have different priorities — and once you understand what each style is optimising for, the formatting rules stop feeling arbitrary. This guide explains who uses each, how they differ, and how to choose.

First, the most important rule

Use the style your assignment or publication requires. This is not a matter of preference. If your instructor, journal or institution specifies a style, that decision is already made — your only job is to apply it consistently. The guidance below is for when the choice is genuinely yours, or when you want to understand why the styles differ.

APA — the social sciences style

APA (American Psychological Association) style dominates psychology, education, nursing, business and the social sciences generally.

Its defining feature is that the date is prominent — it appears right after the author. That is deliberate: in fast-moving empirical fields, how recent a source is matters enormously. A 2003 study and a 2024 study on the same topic are very different evidence.

An APA reference for a book looks like:

Smith, J. (2024). Title of the book. Publisher.

Note: author's first name reduced to an initial, year in parentheses up front, title in sentence case and italics.

MLA — the humanities style

MLA (Modern Language Association) style is standard in literature, languages, philosophy and the humanities.

Its defining feature is that the page number is prominent and the date is not. In literary analysis, where in a text something appears matters more than what year the edition was printed. MLA in-text citations are author-and-page: (Smith 42).

An MLA reference for a book looks like:

Smith, John. Title of the Book. Publisher, 2024.

Note: author's full first name, no parentheses around the date, title in title case and italics, date at the end.

Chicago — the history and publishing style

Chicago style is common in history, the arts, and much professional publishing. It is the most flexible of the three — and it comes in two systems:

• Notes-bibliography: sources are cited in footnotes or endnotes, with a full bibliography. Favoured in history and the humanities.
• Author-date: similar to APA, with parenthetical citations. Favoured in the sciences that use Chicago.

A Chicago bibliography entry for a book looks like:

Smith, John. Title of the Book. City: Publisher, 2024.

Note the inclusion of the city of publication — a detail APA and MLA dropped years ago.

The differences at a glance

The styles diverge on a handful of consistent points:

• Author's name: APA uses initials (Smith, J.); MLA and Chicago use the full name (Smith, John).
• Date position: APA puts it up front in parentheses; MLA and Chicago put it near the end.
• Title case: APA uses sentence case for titles; MLA and Chicago use title case.
• In-text citation: APA is author-date (Smith, 2024); MLA is author-page (Smith 42); Chicago notes-bibliography uses footnote numbers.
• The reference list is called: "References" in APA, "Works Cited" in MLA, "Bibliography" in Chicago.

None of these is better. Each reflects what its field cares about most: recency for APA, location-in-text for MLA, flexibility for Chicago.

How to choose when it is up to you

• Writing in psychology, education, business, nursing, or a social science → APA.
• Writing in literature, languages, philosophy, or the humanities → MLA.
• Writing in history, art history, or for general publication → Chicago.
• Genuinely unsure and unconstrained → APA is the safest default outside the pure humanities; it is the most widely recognised.

Consistency beats perfection

Whichever style you use, the cardinal rule is consistency. A reference list that is half-APA and half-MLA looks careless even if every individual entry is defensible. Pick the style, apply it to every source, and check the small details — punctuation, italics, capitalisation — because that is where marks are quietly lost.

To get every source formatted correctly in all three styles from a single set of details, use the Citation Generator. Treat its output as an accurate first draft, then verify anything unusual — multiple authors, missing dates, edited volumes — against your assignment's style guide.

The short version

APA, MLA and Chicago differ because their fields differ: APA foregrounds the date (social sciences), MLA foregrounds the page (humanities), and Chicago is the flexible, footnote-friendly choice (history and publishing). Use whichever your assignment requires; if the choice is yours, match the style to your field. Apply it consistently, and let the Citation Generator handle the formatting.