How to Cite AI: APA, MLA, Chicago, Harvard

Knowing how to cite AI is now essential for academic and professional writing. If you used ChatGPT to brainstorm, Claude to summarize research, or Gemini to generate a first draft, you probably need to cite it. The challenge is that each citation style handles AI differently, and the guidelines have been updated multiple times since 2023.

This guide covers the current rules for APA, MLA, Chicago, and Harvard, with copy-paste citation examples for each. It also covers the question most students actually have: when do I need to cite AI, and when is it just a tool?

When Do You Need to Cite AI Tools?

Not every interaction with AI requires a citation. Here's the general rule:

Cite AI when you use its output directly in your work: quoted text, paraphrased arguments, generated data, or content that shaped your final text.

Don't cite AI when you use it the way you'd use a spell checker or calculator, as a tool that assists your process but doesn't contribute content. Running your draft through Grammarly doesn't need a citation. Asking ChatGPT to generate three paragraphs that you include in your essay does.

The gray area is where AI helped you develop ideas. If you brainstormed with ChatGPT and those ideas ended up in your paper, many institutions now recommend at least a disclosure statement, even if formal citation isn't required.

When in doubt, ask your instructor or check your institution's AI policy. Over 70% of universities now have formal AI use policies, and they vary significantly. Harvard, for example, publishes detailed guidance through its library system that includes specific citation formats and disclosure requirements.

Understanding when and how to use AI ethically is a skill in itself. The AI Academy teaches responsible AI usage alongside practical techniques, so you build good habits from the start.

APA Format (7th Edition)

APA treats AI-generated text as the output of an algorithm, with the AI company listed as the author.

Reference List Format

In-Text Citation

According to ChatGPT, the primary factors include... (OpenAI, 2026).

APA-Specific Rules

• Include the exact version or date of the model you used
• APA recommends including the full AI-generated text as an appendix if you directly quote it
• Reference it at least once in your in-text citations
• The date in the reference should be the date you generated the content, not the model's release date

MLA Format (9th Edition)

MLA updated its guidance in August 2025, and it differs significantly from APA. MLA does not treat AI as an author. Instead, the prompt or a description of the generated content comes first.

Works Cited Format

In-Text Citation

The AI suggested that "the trilogy's central theme is the corruption of power" ("Identify the main themes").

MLA-Specific Rules

• The prompt text is the "title" of the entry; put it in quotation marks
• Italicize the AI tool name (like a container title)
• Include both the version date and the date you generated the content
• If the prompt is very long, you can shorten it in the works cited entry

Chicago Style (17th Edition)

Chicago recommends treating AI-generated content like a personal communication, similar to how you'd cite a phone call or private conversation. This means no bibliography entry.

Footnote/Endnote Format

1. Text generated by ChatGPT, OpenAI, February 15, 2026, https://chat.openai.com.

2. Claude (3.5 Sonnet), response to "Explain the causes of the 2008 financial crisis," Anthropic, February 15, 2026.

Chicago-Specific Rules

• Do not include AI sources in your bibliography or reference list
• Use footnotes or endnotes only
• Include your prompt if it's relevant to the reader
• Some professors may want a bibliography entry despite Chicago's recommendation, so always check

Harvard Format

Harvard referencing follows a structure similar to APA, with the AI company as author.

Reference List Format

OpenAI (2026) ChatGPT [Large language model]. Available at: https://chat.openai.com (Accessed: 15 February 2026).

Anthropic (2026) Claude 3.5 Sonnet [Large language model]. Available at: https://claude.ai (Accessed: 15 February 2026).

In-Text Citation

AI-generated analysis suggests three primary factors (OpenAI, 2026).

Harvard-Specific Rules

• Include the access date since AI outputs are not static
• Specify the model version in the title if possible
• Some universities using Harvard style have published their own AI citation addenda, so check your institution's library guides

Quick Reference Table

How to Cite AI Image Generators

If you used DALL-E, Midjourney, or Stable Diffusion to generate images in your paper, cite them similarly:

For more on AI image generation, our guide on how to use ChatGPT to create images covers the tools and techniques.

The Disclosure Statement

Beyond formal citations, many institutions now require a separate AI disclosure statement. This is a paragraph (usually at the end of your paper, before references) explaining how you used AI.

Even if your professor doesn't require this, including one demonstrates academic honesty and protects you from accusations of undisclosed AI use.

Knowing how to disclose and cite AI properly is part of using it effectively. Our AI Academy covers the ethical and practical sides of working with AI tools in professional and academic settings.

Common Mistakes When Citing AI

1. Citing the AI model instead of the company. The author is OpenAI, not "ChatGPT." It's Anthropic, not "Claude."

2. Using the model release date instead of your usage date. The date in your citation is when you generated the content, not when GPT-4 was released.

3. Forgetting to save the conversation. If your citation style requires a URL (APA, MLA with link), save or share the chat before you close it. You can't reconstruct an AI conversation later.

4. Citing when you should disclose (or vice versa). Using AI for brainstorming might need only a disclosure statement. Using AI-generated text directly in your paper needs a formal citation.

5. Assuming your institution follows the standard style guide exactly. Many universities have published their own AI citation amendments that add or modify requirements. Always check your school's library guides.

If you're a student using AI for academic work, our guides on how to use AI for studying and writing essays with ChatGPT cover the practical techniques. For broader questions about ethical AI use, our guide on how to use AI responsibly covers the principles beyond citation, and knowing how to cite properly is what keeps you in good standing.

Staying Current

Citation guidelines for AI are still evolving. APA and MLA have both updated their recommendations multiple times since 2023, and more changes are likely as AI use becomes standard in academic work.

The safest approach: check your style guide's official website at the start of each semester.

For a comprehensive foundation in using AI tools the right way -- citation, disclosure, and beyond -- the AI Academy keeps its curriculum updated as guidelines evolve.

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