How to Use a Chicago 18th Edition Citation Generator

A Chicago 18th edition citation generator fills in most of a footnote in about two seconds, and the part it gets wrong is almost always the part the 18th edition changed. Chicago released the 18th edition in 2024, replacing the 17th from 2017, and it cut several elements that had been mandatory for decades. Tools trained on older examples keep printing them. This guide gives you the current element order from the manual, ten checks to run on whatever the generator hands you, and a worked correction for each one.

What a Chicago 18th edition citation generator can and cannot know

A generator reads metadata from a DOI, ISBN, or URL and pours it into a template. It knows the author string, the title string, the year, and usually the publisher. That covers the mechanical part.

What it cannot see is which of Chicago's two systems your department wants, whether the thing you are citing is a report or a web page or a chapter, whether the metadata it scraped was right in the first place, and which edition of Chicago its own template was built from. That last one is the expensive gap. A template written against the 17th edition produces citations that look completely plausible and are quietly out of date, because the 18th edition's changes were mostly deletions. Nothing looks broken when a tool includes something it no longer needs to.

So the workflow that works is: generate, then check. The ten checks below are ordered by how often they catch something.

Pick the system before you generate anything

Chicago describes two citation systems, and they produce entirely different-looking documents.

Notes-bibliography uses superscript numbers in the text, full details in a footnote or endnote, and an alphabetical bibliography at the end. It is standard in history, philosophy, religious studies, and much of the humanities.

Author-date uses a parenthetical (Author Year, page) in the text and a reference list at the end. It is standard in the natural sciences, the social sciences, and a good deal of business and education writing.

Most generators default to one and bury the other in a dropdown. Setting this wrong produces output that is correctly formatted for a system nobody asked for, which no amount of proofreading will fix. Our full walkthroughs of each system are here: Chicago notes-bibliography and Chicago author-date.

The 18th edition formats, straight from the manual

Notes-bibliography

Book:

Full note: Charles Yu, Interior Chinatown (Pantheon Books, 2020), 45. Short note: Yu, Interior Chinatown, 48. Bibliography: Yu, Charles. Interior Chinatown. Pantheon Books, 2020.

Chapter in an edited book:

Full note: Kathleen Doyle, "The Queen Mary Psalter," in The Book by Design: The Remarkable Story of the World's Greatest Invention, ed. P. J. M. Marks and Stephen Parkin (University of Chicago Press, 2023), 64. Short note: Doyle, "Queen Mary Psalter," 65. Bibliography: Doyle, Kathleen. "The Queen Mary Psalter." In The Book by Design: The Remarkable Story of the World's Greatest Invention, edited by P. J. M. Marks and Stephen Parkin. University of Chicago Press, 2023.

Titles of books and journals are italicized; article and chapter titles take quotation marks.

Author-date

Book:

Reference: Binder, Amy J., and Jeffrey L. Kidder. 2022. The Channels of Student Activism: How the Left and Right Are Winning (and Losing) in Campus Politics Today. University of Chicago Press. In-text: (Binder and Kidder 2022, 117-18)

Journal article:

Reference: Dittmar, Emily L., and Douglas W. Schemske. 2023. "Temporal Variation in Selection Influences Microgeographic Local Adaptation." American Naturalist 202 (4): 471-85. https://doi.org/10.1086/725865. In-text: (Dittmar and Schemske 2023, 480)

The year moves directly after the author in author-date, and the reference list is alphabetical by surname.

Ten checks to run on generator output

1. Delete the publisher's city

This is the single most common stale output. Through the 17th edition, a book citation named the city: Chicago: University of Chicago Press, 2022. The 18th edition no longer requires a place of publication for books published since 1900 (14.30).

Generator gives: Yu, Charles. Interior Chinatown. New York: Pantheon Books, 2020. 18th edition: Yu, Charles. Interior Chinatown. Pantheon Books, 2020.

Books published before 1900 keep the place, so a citation of an 1890 treatise is a genuine exception.

2. Count the authors against the new thresholds

The 18th edition changed both thresholds, and it changed them differently for notes and for bibliography entries.

In a bibliography or reference list, list up to six authors. With more than six, list the first three and add "et al." (13.23, 13.78). The 17th edition listed up to ten, so a generator running the old rule will print seven or eight names where three plus "et al." belongs.

In a note or an author-date parenthetical, name up to two authors. With three or more, name the first and add "et al."

Generator gives (note): Rachael A. Bay, Noah Rose, and Rowan Barrett, "Predicting Responses to Contemporary Environmental Change," 465. 18th edition (note): Rachael A. Bay et al., "Predicting Responses to Contemporary Environmental Change," 465.

That three-author note is exactly what a 17th-edition template produces, because the old rule allowed three names before "et al." kicked in.

3. Replace "ibid." with a shortened note

The 18th edition discourages "ibid." and prefers a shortened citation instead (13.37). Chicago's reasoning is practical: a shortened note is usually under a line, so "ibid." saves no space, and in formats that link to one note at a time it leaves the reader with no idea which source is meant.

Generator gives: 12. Ibid., 51. 18th edition: 12. Yu, Interior Chinatown, 51.

The shortened form has three permitted shapes: author-title (Chicago's regular short form), author-only, and title-only.

4. Repeat the author's name instead of a 3-em dash

Older bibliographies replaced a repeated author's name with a row of three em dashes followed by a period. Chicago now prefers repeating the name (13.72, 13.113).

Generator gives: [three em dashes]. Interior Chinatown. Pantheon Books, 2020. 18th edition: Yu, Charles. Interior Chinatown. Pantheon Books, 2020.

If your bibliography has a run of entries by the same author, this affects every one after the first.

5. Put the DOI in URL form

A DOI belongs in the reference as a full https://doi.org/ address. The bare doi:10.1086/725865 style that older tools emit is out.

Generator gives: doi:10.1086/725865 18th edition: https://doi.org/10.1086/725865

6. Drop the month or season from journal articles

Publication months and seasons for journal articles can usually be omitted now (13.26). Volume, issue, and year carry the load.

Generator gives: American Naturalist 202, no. 4 (May 2023): 471-85. 18th edition: American Naturalist 202, no. 4 (2023): 471-85.

7. Chapter page ranges are now optional

A bibliography entry for a chapter in an edited book no longer has to carry the chapter's full page range (14.8). Many generators still append it. Keeping it is not an error, so treat this as a consistency decision: include the ranges everywhere or nowhere, and follow your department's style sheet if it has one.

8. Check the "Turabian" setting is not doing something else

This one catches people who assume the two labels are interchangeable. Kate L. Turabian's A Manual for Writers of Research Papers, Theses, and Dissertations, 9th edition (2018), is aligned to Chicago's 17th edition. A tenth edition matching CMOS 18 has been announced for 2026, but the 9th is what the Turabian label still means in most tools today.

So selecting "Turabian" in a generator gives you 17th-edition-era output: publisher cities included, older author thresholds, the whole set of changes above reversed. If your instructor said "Turabian," ask which manual they mean before you generate two hundred footnotes.

9. Verify the metadata, not the format

A generator formats whatever it was handed. If the DOI lookup returned a truncated subtitle, a journal's issue number as part of the volume, or an editor in the author field, the output is immaculately formatted and wrong. Open the source and compare the author list, the year, the full title including subtitle, and the volume and issue against what the tool produced.

This is the check that has nothing to do with Chicago and catches the most consequential errors.

10. Confirm the shortened note matches the full note

Generators that produce footnotes often produce the full form every time and leave you to shorten them, or shorten them mechanically and lose the distinguishing word. A short note has to point unambiguously at one entry in your bibliography. If you cite two Yu books, Yu, Interior Chinatown, 48 works and Yu, 48 does not.

Special cases

No author

Start with the title, in both the note and the bibliography. For an organization that is effectively the author, use the organization: Chicago's own example puts Google in the author slot for a corporate privacy policy.

Note: "Privacy Policy," Privacy & Terms, Google, effective November 15, 2023, https://policies.google.com/privacy. Short note: Google, "Privacy Policy." Bibliography: Google. "Privacy Policy." Privacy & Terms. Effective November 15, 2023. https://policies.google.com/privacy.

No date

Use n.d. in place of the year. In author-date, that becomes (Smith n.d.) in the text and Smith, Jane. n.d. in the reference list. Where a page carries a "last modified" or "effective" date instead of a publication date, use that and label it, as the Google example does.

A book published before 1900

Keep the place of publication. The 18th edition's deletion of the city applies to books published since 1900, so early printed sources retain it. A generator that strips the city from everything will get these wrong in the opposite direction, which is worth a scan if you work with historical material.

Self-published work

Chicago now prefers "published by the author" over "self-published" (14.36), and the commercial platform no longer needs naming. Amazon Kindle Direct Publishing in the publisher slot is 17th-edition habit.

AI-generated content

The 18th edition added guidance for citing AI-generated text (14.112) and AI-generated images (3.38), and it asks authors to state whether and to what extent AI was used in the work (4.51, 4.76). Most generators have no template for this at all, so expect to write it by hand and to check your instructor's own policy, which may be stricter than Chicago's.

An archived or dead page

The 18th edition added guidance for citing pages via the Wayback Machine and similar archives (14.104). If the live URL is gone, cite the archived version and give its capture date.

The same person as author and editor

When one person is cited as both author and editor of a work, give the name in full for both roles (14.12) rather than shortening the second appearance.

Common mistakes and how to avoid them

• Mixing the two systems in one paper. A footnote and a parenthetical citation on the same page means a generator setting changed partway through. Pick a system at the outset and regenerate anything that predates the decision.
• Trusting a library guide's edition label. Guides that say "18th edition" in the heading sometimes still carry 17th-edition examples underneath, because updating example blocks is slow work. Check the examples against a change you know about, such as the publisher city, before relying on the page.
• Italicizing the wrong title. The larger work is italicized and the smaller one takes quotation marks: a journal is italic and its article is quoted, a book is italic and its chapter is quoted. Generators handle this well when the source type is set correctly and badly when a chapter has been imported as a book.
• Letting the bibliography and the notes disagree. They are generated separately by most tools. If you fixed a name in one, fix it in the other.

Quick-reference table