APA vs MLA vs Chicago Citation Styles

APA, MLA, and Chicago are the three citation styles most college students encounter, and they differ in both what they emphasize and how they format a reference. None is more "correct" than another; each was built for a different kind of reader with different information needs.

This is for anyone assigned a paper that requires a specific citation style, or trying to figure out which one applies when an assignment sheet doesn't say directly.

APA (American Psychological Association)

Common in psychology, education, and the social sciences. In-text citations lead with the author's name and year, like (Smith, 2023), since APA emphasizes how recent a source is, which matters in fields where research findings can be superseded quickly. The reference list uses "Last, F. M." author formatting and sentence-case titles. APA is currently in its 7th edition, published in 2019 by the American Psychological Association.

MLA (Modern Language Association)

Common in literature, languages, and the humanities. In-text citations use the author's name and a page number, like (Smith 42), since MLA emphasizes locating the exact passage in a text, useful for close reading of literary works. Titles in the works-cited list use title case and are placed in quotation marks or italics depending on the source type. MLA is currently in its 9th edition, published in 2021 by the Modern Language Association.

Chicago

Common in history and some publishing contexts. Chicago has two distinct systems: notes-bibliography, which uses numbered footnotes with a matching bibliography, and author-date, which uses in-text parenthetical citations similar to APA. Check which variant your instructor wants, since the two look quite different on the page even though both fall under "Chicago style." The Chicago Manual of Style is currently in its 18th edition, published in 2024, though many programs and instructors haven't yet updated their guidance from the widely used 17th edition (2017), so confirm which edition your course expects.

Why the styles differ at all

Each style developed to serve a specific readership. APA readers in the social sciences often care most about whether a finding is current, so the year comes first. MLA readers in literary studies often want to verify an exact quote or passage, so the page number comes first. Chicago's historical roots favor detailed footnotes that can hold extra context (a translator's note, a source's provenance) that a simple parenthetical citation can't accommodate. None of these are arbitrary rules; they're each shaped by what that discipline's readers most need to check.

Quick way to tell which one you need

Check your syllabus or assignment sheet first. If it doesn't say, the subject area is a reasonable guide: social science coursework usually wants APA, literature and humanities coursework usually wants MLA, and history coursework often wants Chicago. When genuinely unsure, ask your instructor rather than guessing, since switching styles after a paper is drafted is far more time-consuming than confirming beforehand. For the full rule sets, the APA Style website, the MLA Style Center, and the Chicago Manual of Style are each the authoritative source, maintained directly by the organization that publishes the style.

Generate citations in any of these styles, and 11 others, with the citation generator.