APA vs MLA: Key Differences Explained

APA (American Psychological Association) and MLA (Modern Language Association) are the two most common citation styles used in universities. The core difference comes down to what each discipline considers most important when citing a source.

APA was designed for the social sciences. In psychology, education, and sociology, when a study was conducted matters enormously — a 1985 study on memory is far less authoritative than a 2023 study. So APA puts the publication year right after the author name in every in-text citation: (Smith, 2023).

MLA was designed for the humanities. In literary analysis or history, page numbers matter more than dates — you need to point your reader to the exact passage you are discussing. So MLA uses (Smith 47) in-text, with no year. The full publication details, including the year, appear only in the Works Cited list.

The in-text citation format is the most visible difference between APA and MLA. Here is the same source cited in both styles:

Working memory is degraded after even one night of poor sleep (Walker, 2017, p. 158).

Working memory is degraded after even one night of poor sleep (Walker 158).

In APA, the year always appears after the author name. In MLA, the year never appears in the in-text citation — it belongs only in the Works Cited entry. Page numbers are introduced with "p." in APA but appear with no label in MLA.

Both styles require a list of all sources at the end of your paper. APA calls this the Reference List; MLA calls it Works Cited. The formatting rules are different in significant ways.

Here is the same book formatted in both styles:

Walker, M. (2017). Why we sleep: Unlocking the power of sleep and dreams. Scribner.

Walker, Matthew. Why We Sleep: Unlocking the Power of Sleep and Dreams. Scribner, 2017.

• Author format: APA uses initials (Walker, M.); MLA uses the full first name (Walker, Matthew)
• Year placement: APA puts the year in parentheses after the author; MLA puts it at the end
• Title capitalization: APA uses sentence case for book titles (Why we sleep); MLA uses title case (Why We Sleep)
• Publisher: APA omits the publisher location; MLA does too (since MLA 8th edition)

One of the most commonly confused differences is how each style capitalizes titles. APA uses sentence case for article and book titles in the reference list — only the first word, proper nouns, and the first word after a colon are capitalized. Journal names are written in title case.

MLA uses title case throughout — every major word is capitalized in every title. Both styles italicize book and journal titles. Both styles put article titles in quotation marks, not italics.

Attention restoration theory: A systematic review of existing research.
Journal of Environmental Psychology, 45, 112–123.

"Attention Restoration Theory: A Systematic Review of Existing Research."
Journal of Environmental Psychology, vol. 45, 2016, pp. 112–123.

The answer is almost always: whichever one your instructor specifies. If the assignment guidelines do not mention a style, use the table below as a starting point based on your discipline.

• Psychology, education, sociology, nursing, social work → APA
• English literature, comparative literature, modern languages → MLA
• History, philosophy, religious studies, fine arts → Chicago (notes-bibliography) or MLA
• Communication, media studies, political science → APA or Chicago depending on the program
• Business, economics → APA or Chicago author-date

If you switch universities or programs, the expected style may change. Always read the assignment brief carefully. Submitting an MLA paper for an APA course — or mixing the two within a paper — will cost you marks even if your content is excellent.

• In-text format: APA = (Author, Year) | MLA = (Author page)
• List title: APA = References | MLA = Works Cited
• Author format: APA = Last, F. | MLA = Last, First
• Book title capitalization: APA = Sentence case | MLA = Title Case
• Year in reference: APA = After author name | MLA = At end of entry
• Primary disciplines: APA = Social sciences | MLA = Humanities
• Latest edition: APA = 7th (2020) | MLA = 9th (2021)

Both styles are updated periodically. APA released its 7th edition in 2020 with several changes, including new rules for citing social media and removing the publisher location requirement for books. MLA released its 9th edition in 2021 with clarifications on digital sources. Make sure you are using the current edition when you cite.