Do you know the big differences between AP, APA, Chicago, and MLA styles?

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Be intentional with your writing

Chances are you’ve heard of AP, APA, Chicago, and MLA styles of writing. You’ve probably even used them. But do you know the big differences between these four popular writing styles?

What are the AP, APA, Chicago, and MLA writing styles?

Before we get into the differences between these four writing styles, we should explain them all a little more.

AP Style: AP, or Associated Press, style is most commonly used by journalists.

APA Style: American Psychological Association (APA) style is common in science and some college classes.

Chicago Manual of Style: The Chicago Manual of Style is arguably the most comprehensive, often used in publishing.

MLA Style: MLA, or Modern Language Association, style is the one you’re likely most familiar with. It’s the style your teachers probably taught you in high school.

What are the biggest differences?

Oxford Comma

AP style advises against using the Oxford comma.

The Chicago Manual of Style and the MLA and APA style guides recommend using the Oxford comma.


AP and APA both spell out numbers below 10 and use numerals for numbers 10 and over.

However, for APA style, when the numbers involve exact times, dates, ages, scores, points on a scale, or monetary amounts, you use numerals. For example, “He turns 7 next week.” vs. “I think he’s six years old.”

MLA spells out numbers that are one to two words (e.g., one hundred, twenty-three), and use numerals for the rest (e.g., 143, 1,115).

The Chicago Manual of Style suggests spelling out numbers between 0 and 99 as well as any rounded numbers or numbers that end in hundred, thousand, hundred thousand, million, or billion (e.g., 220, one thousand two hundred).

If the number starts a sentence, you always spell it out (“Two hundred days had passed since he last saw her.”)

Book and Article Titles

In AP style, you never italicize or underline book, poem, or newspaper titles. Instead, you place quotation marks around books, plays, poems, lectures, etc. For newspapers, you simply write the name of the publication — no quotation marks or italics, e.g., The Washington Post.

For APA style, place quotation marks around journal articles, song titles, articles from collections, etc. Italicize or underline books, edited collections, etc.

For the Chicago Manual of Style, use quotation marks around the title of articles titles and chapter titles; italicize longer titles like periodicals or books.

MLA suggests you italicize books and websites. Place quotation marks around song titles, newspaper articles, journal articles, and magazine articles.

State Abbreviations

AP style suggests abbreviating states as such: California=Cal., Alabama=Ala., New Hampshire=N.H., etc. Writers using AP style do not abbreviate Alaska, Hawaii, Idaho, Iowa, Maine, Ohio, Texas, and Utah.

The APA does not have a specific suggestion on whether to abbreviate state names.

Chicago Manual of Style and MLA style suggest abbreviating states by the two-letter postal code (e.g., Florida=FL, Maryland=MD, California=CA, etc.)

Why do I need to know these differences?

Before you start writing, decide which style you will use. If you do not plan to follow any particular style or if you decide to take a little from each style, you should still outline the formatting and citation style you plan to use ahead of time. Inconsistency may appear unprofessional. For example, if you have the title of a journal in quotes on one page and italicized on another, it could confuse readers.

At We Do Web Content, we have our own style that draws from some of the styles listed above. For example, we always spell out numbers until 10 like AP and APA styles, but we also abbreviate states with the postal code like MLA style. While we use characteristics of different styles, we always ensure we are consistent.

For help with content writing, give us a call: 888-521-3880.