Citation guides

How to Cite ChatGPT and Other AI Tools

How APA, MLA and Chicago say to cite ChatGPT, Claude and Gemini, a Harvard example (there is no official one) and how to write an AI disclosure.

AI chatbots are now part of how students work, and citation styles have caught up. APA revised its advice on citing AI in September 2025 and MLA in August 2025, and Chicago's current advice follows its 18th edition (2024). Harvard has no single official format, so universities differ. Before formatting anything, though, there is a more important question.

First: check what your course allows

Universities differ enormously. Some ban generative AI outright, some allow it with disclosure, and some encourage it. No citation format will save an assignment that broke the rules, so read your course guide or ask your teacher first. If AI use is allowed, cite or disclose it as below.

APA citation for ChatGPT

APA treats the AI company as the author. Since September 2025 it no longer asks for a version number by default: use the name of the tool (ChatGPT) or of the model (for example ChatGPT-5). There are two patterns. Cite the tool in general when you only used it for support, or cite a specific chat when it has a share link and the chat itself helps your reader.

For the tool in general, the year is when the tool was most recently updated. For a chat, the date is the day the chat took place. Describe your prompts in the running text, for example in the Method section. APA does not put prompts in the reference itself, and an appendix is optional if it helps your reader.

MLA citation for ChatGPT

MLA does not treat the AI tool as an author. It starts from a description of the prompt (as the title of the "work"), then names the tool, the model, the company and the date the text was generated. A stable share link is preferred as the location; if the tool offers none, give its general URL. This is MLA's own example.

Harvard citation for ChatGPT

Harvard is a family of styles with no single official format, and universities handle AI differently. Many UK universities follow Cite Them Right, which treats the question you asked as the title of the work and the response as a communication to you. The example below follows that template, as shown in Robert Gordon University's guide. Check your own university's variant, or use the Harvard reference generator for ordinary sources and add AI entries by hand.

Claude, Gemini and Copilot

The pattern is the same for every chatbot; only the company, tool or model and URL change. These are APA's own examples for citing a tool in general. For Copilot, use Microsoft as the author in the same way.

Chicago citation for ChatGPT

Chicago (18th edition) says that you must credit AI tools when you use the text they generate, but for most writing you can simply name the tool in your text, for example "The following recipe for pizza dough was generated by ChatGPT". If you need a more formal citation, such as in a student paper or a research article, use a numbered footnote or endnote, with the URL copied from the share button the tool provides.

If you edited the AI-generated text, say so in the text or at the end of the note, for example "edited for style and content". Library guides to the 18th edition report that Chicago does not usually put AI in the bibliography, and that if an entry is required it goes under the developer's name (OpenAI), not the tool's. Ask your instructor which pattern they expect.

Difficult cases, answered

AI invented a source that does not exist

Language models can generate references that look plausible but point to papers that were never written, and MLA warns that AI tools can make up sources. Never cite a reference an AI gave you without opening it yourself: search the title, check the DOI resolves, and confirm the paper says what the model claimed. You are the author of your paper, and APA is clear that the human author must check the AI's output for accuracy, so "the AI told me" does not shift that responsibility.

AI summarised a real source for you

Cite the source, not the AI, but only after reading the relevant part yourself. A summary you have not verified is a claim about a paper rather than knowledge of it, and summaries routinely drop the qualifications that make an academic finding defensible.

You used AI only for grammar or rewriting

Acknowledge it. APA asks you to disclose AI used to edit or refine your own writing and to cite the tool generally, and MLA asks you to acknowledge editing or translation in a note or in your text. Ordinary spell-checking is different from having an AI rewrite your sentences. Some courses restrict AI use for this purpose, so check first.

You used AI to generate code or analysis

Say so, in the method section rather than only in a reference. Name the tool and model, state which part it produced, and describe how you tested the output. APA notes that whether to cite the full chat that contains the code depends on how central the code is to your work.

The conversation cannot be shared

Most chat tools, including ChatGPT, now offer a share link that gives a chat its own URL. APA and MLA both prefer that link when you cite a specific chat, and Chicago asks for it in the note. If your tool has no share link, MLA says to give the tool's general URL. With APA you can cite the tool in general and describe your prompts in the text.

Your school forbids AI entirely

Then no citation format makes it acceptable. Citing a prohibited tool documents the breach rather than excusing it. If you have already used it, tell your teacher before submitting rather than after.

Writing an AI disclosure statement

APA says that the details of what AI use is allowed and how it should be disclosed depend on factors such as instructor, departmental and publisher policies. Many courses therefore ask for a short disclosure, alongside or instead of a formal citation, even for uses such as grammar help, brainstorming or outlining. A good disclosure names the tool and model, states exactly what it was used for, and confirms how you checked the result.

Vague statements ("AI was used to help write this") tell the reader little. Specific ones, naming the tool and the exact task, hold up much better if a marker asks follow-up questions.

The golden rule for citing AI

• Cite AI when you quote, paraphrase or incorporate its output, when it edited or refined your writing, or when disclosure is required.
• Do not cite AI as evidence for facts; find the underlying source and cite that instead.
• Verify everything. If a chatbot names a study, open the study before it goes anywhere near your reference list.

For the sources you find while verifying, paste the link or DOI into the free citation generator and the reference formats itself.