How to Cite Sources in APA, MLA & Chicago Styles

By ZeroFee Tools · October 15, 2026 · 7 min read

Citations are the receipts of academic writing. They show where every borrowed idea came from, give credit to the original authors, and let your readers check your work. The trouble is that the three major styles, APA, MLA, and Chicago, each arrange the same facts in a different order. This guide compares all three side by side with website, book, and journal examples, flags the mistakes that cost writers the most credibility, and shows how the free Citation Generator builds every reference for you.

Every style answers the same four questions: who wrote it, when was it published, what is it called, and where can I find it. APA leads with author and date, MLA leads with author and page, and Chicago gives you a choice between footnotes and author-date. Learn which style your assignment needs, keep the same pattern from the first citation to the last, and let the free citation generator handle the commas and italics for you.

What are APA, MLA, and Chicago styles?

APA (American Psychological Association) is the standard for the social sciences and uses author-date citations; MLA (Modern Language Association) serves the humanities and uses author-page citations; Chicago (The Chicago Manual of Style) serves history and publishing and offers both notes-bibliography and author-date systems.

APA style, now in its 7th edition, dominates psychology, education, business, nursing, and much of the social sciences. Its signature move is putting the publication year front and center, because in those fields how recent a finding is often matters as much as who reported it. In the text you write (Lee, 2024), and the reference list gives the full details. When a source has three or more authors, APA shortens the in-text citation to the first author plus et al. from the very first mention.

MLA style, in its 9th edition, is the home of literature, languages, cultural studies, and the arts. Instead of dates, MLA in-text citations point to the author and the page where the idea appears, like (Lee 12), because the editions being quoted can matter more than the year. Its signature concept is the container: an article sits inside a journal, a chapter inside a book, a video inside a platform, and MLA asks you to record that nesting carefully.

Chicago style, in its 17th edition, is the publishing world's standard and the default in history. It actually offers two complete systems. Notes and bibliography uses numbered footnotes or endnotes plus a bibliography, which is why history books carry those familiar little superscript numbers. Your instructor, department, or publisher chooses for you; the golden rule is never to mix the systems in one document.

How do you cite a website in each style?

Web citations in all three styles need the same facts: author, date, page title, site name, and URL. APA orders them author, date, italic title, site, URL; MLA orders them author, quoted title, site, date, URL; Chicago notes order them author, quoted title, site, date, URL.

Take a typical article page as our running example:

Notice what changes and what does not. APA italicizes the page title and keeps the full URL including https://. MLA drops the https://, wraps the title in quotation marks, and treats the site as the container. Chicago's footnote looks conversational, with the author's name in natural order, while the bibliography entry flips it. One detail trips up nearly everyone: APA only asks for a retrieval date on pages designed to change over time, like a live dashboard. A normal published article does not need one.

How do you cite a book in each style?

Book citations need author, year, title, edition, and publisher in every style. APA gives Author, A. (year). Italic title. Publisher. MLA gives Author. Italic title. Publisher, year. The Chicago bibliography gives Author. Italic title. Place: Publisher, year.

Using a second-edition book as the example:

The edition line deserves attention because students leave it out constantly. If the book says "Second edition" or "Revised edition" on the title page, record it; a first edition needs no edition note at all. Also note the capitalization split: APA uses sentence case for book titles in the reference list (only the first word and proper nouns capitalized), while MLA and Chicago use title case.

How do you cite a journal article in each style?

Journal articles add volume, issue, and page range to the mix, and APA and Chicago use the DOI when one exists. All three styles treat the article title differently from the journal title: the article gets sentence case or quotation marks, while the journal name gets italics.

The DOI, the permanent link starting with 10., is the most valuable line in a journal citation, so prefer it over a plain URL whenever the article has one. APA formats it as a full https://doi.org link; Chicago accepts the DOI alone. Also watch the ampersand: APA uses & between authors in the reference list, while MLA and Chicago spell out "and." It is a tiny difference that markers notice immediately.

How to generate a citation in 5 steps

1. Open the free Citation Generator and pick your style. Choose APA, MLA, or Chicago before you enter anything, because the field order and punctuation follow from that choice.
2. Select the source type. Website, book, and journal article each have their own form, so the tool only asks for the fields your style actually needs.
3. Copy details from the source itself. Take the author and title from the page, the title page, or the article header, not from a search result snippet, which often truncates or rewords them.
4. Preview and spot-check the result. Compare the output against the patterns in this guide: correct case, correct italics, DOI or URL present, edition noted where it applies.
5. Paste and match your in-text citations. Copy the reference into your bibliography, then make sure every in-text mention, (Lee, 2024) or (Lee 12) or a footnote number, points to an entry that actually exists there.

6 common citation mistakes to avoid

• Mixing styles in one paper. APA in-text citations with MLA-style works cited is the classic error. Decide once, at the start, and stay there.
• Citing the container instead of the source. The journal is not the article, and the website is not the page. The article or page title carries the quotes or sentence case; the journal or site name carries the italics.
• Forgetting the retrieval detail. A journal article without its DOI, or a webpage without its URL, cannot be checked. If the reader cannot find it, the citation has failed.
• Wrong capitalization. APA reference titles use sentence case, while MLA and Chicago titles use title case. Applying the wrong case rule to every entry is an easy way to lose points on all of them at once.
• Misusing et al. APA uses the first author plus et al. for three or more authors from the first mention; MLA uses it for three or more as well. With two authors, name them both.
• Trusting any generator blindly. Even a good tool is only as accurate as what you typed. Glance at the output before you submit: authors spelled right, year right, title complete.

Frequently asked questions