Use APA for the sciences, social sciences, psychology and education; MLA for the humanities, literature and language studies; and Chicago for history, parts of the humanities, and book and journal publishing. If your instructor or journal names a style, that requirement overrides any general rule. The citation generator formats a source in whichever of the three you choose.
The three styles describe the same sources, but they arrange the parts differently. The differences are small once you see them side by side, so this guide walks through each one.
Which fields use which style
Citation styles grew out of the needs of different subjects, which is why each one fits a particular kind of writing.
- APA (American Psychological Association) is the standard in psychology, education, nursing, business and the social and natural sciences. These fields value how recent a source is, so the publication year sits up front.
- MLA (Modern Language Association) is used in literature, languages, philosophy, religion and most humanities courses. Close reading matters here, so the citation points to an exact page.
- Chicago (the Chicago Manual of Style) is common in history, art history and the publishing industry. It offers two systems, one built on footnotes and one built on author and year.
When a course or publication specifies a style, follow it exactly. Use the field-based guidance above only when nobody has told you which to use.
How the in-text citation differs
This is the difference you notice first when reading a paper.
- APA uses author and year:
(Garcia, 2019). If you quote directly, add the page:(Garcia, 2019, p. 14). - MLA uses author and page, with no comma and no year:
(Garcia 14). - Chicago notes and bibliography uses a superscript number after the sentence,¹ which points to a footnote at the bottom of the page or an endnote at the back.
- Chicago author-date drops the note and uses parentheses like APA but without the comma:
(Garcia 2019, 14).
So APA leads with time, MLA leads with location in the text, and Chicago lets you choose between a note system and a date system.
Where the date goes
The placement of the publication date is a clear signal of which style you are reading.
In APA the date comes right after the author, both in the text and in the reference entry, because currency of research is the point. In MLA the date moves to the end of the entry and does not appear in the in-text citation at all. In Chicago author-date the date follows the author much as it does in APA; in Chicago notes and bibliography the date appears later in the note and the bibliography entry.
Title formatting
Each style treats titles a little differently in the reference entry.
- APA uses sentence case for article and book titles, capitalising only the first word and any proper nouns: Understanding memory in early childhood. Journal names keep title case.
- MLA uses title case, capitalising the main words: Understanding Memory in Early Childhood.
- Chicago also uses title case, close to MLA.
All three italicise the titles of longer works such as books and journals, and put the titles of shorter works such as articles in quotation marks.
What the reference list is called
The list at the end of your paper has a different name in each style, and the names are not swappable.
- APA: References
- MLA: Works Cited
- Chicago: Bibliography
In every case the list is alphabetised by the author’s surname. Using the wrong heading is a common way to signal that a paper does not actually follow the style it claims to.
The same source in all three styles
Here is one journal article, by an author named Lia Garcia, written three ways so you can compare the layout directly.
| Style | Reference entry |
|---|---|
| APA | Garcia, L. (2019). Understanding memory in early childhood. Journal of Child Development, 12(3), 200-215. |
| MLA | Garcia, Lia. “Understanding Memory in Early Childhood.” Journal of Child Development, vol. 12, no. 3, 2019, pp. 200-15. |
| Chicago | Garcia, Lia. “Understanding Memory in Early Childhood.” Journal of Child Development 12, no. 3 (2019): 200-215. |
Notice the pattern. APA puts the year second and uses an ampersand and sentence case. MLA spells out “vol.” and “no.”, uses title case, and ends with the year. Chicago looks close to MLA but uses a colon before the page range and parentheses around the year.
How to choose quickly
Run through these in order:
- Has anyone told you which style to use? Your instructor, the assignment sheet or the journal’s submission rules decide it. Follow that and stop here.
- No instruction? Match your subject. Sciences and social sciences point to APA, literature and languages point to MLA, history and publishing point to Chicago.
- Still unsure between Chicago’s two systems? Pick notes and bibliography for history and the arts, and author-date for the sciences.
Once you know the style, you do not have to memorise the punctuation. Enter the source details into the citation generator and switch the output between APA, MLA and Chicago.
For step-by-step formatting in one style, see how to cite a website in APA, how to cite in MLA or the Chicago style citation guide.