Here is the secret nobody tells you: there is no such thing as citing a PDF. Once you understand why, the whole problem gets easier.
A PDF is a container, not a source
Students search for how to cite a PDF constantly, and the honest answer is that citation styles do not have a PDF format at all. PDF is just the wrapper the document arrived in, the same way a paperback is a wrapper for a book. What you cite is the thing inside the wrapper: a journal article, a government report, a book chapter, a white paper, a thesis.
So the real job has two steps. First, work out what kind of document your PDF actually is. Second, cite it using that document type's normal format. The file extension never appears in an APA citation, and only optionally in MLA.
Most PDFs you will meet at university are one of four things: a journal article someone downloaded, a report from a government agency or NGO, a chapter scanned from a book, or lecture materials your instructor uploaded. Each has its own pattern below.
Step one: find the real details inside the PDF
Before formatting anything, mine the PDF itself for metadata. The details you need are almost always in one of these places:
The cover page
Reports and white papers put the publisher, authors and year on page one. Theses put the university and year there too.
The first page header or footer
Journal article PDFs print the journal name, volume, issue, page range and often the DOI in the header or footer of the first page.
The fine print on the last pages
Government and NGO reports hide the publication date, report number and publisher in the back matter or the inside cover.
The DOI line
If you can find a DOI anywhere in the document, you are done hunting. Paste the DOI into a citation generator and every other field fills itself from the publisher's own records.
Citing a PDF report in APA 7th edition
Reports are the most common truly PDF-shaped source. The APA 7 pattern is:
Author, A. A. (Year). Title of report (Report No. 123). Publisher. URL
World Health Organization. (2023). Global tuberculosis report 2023. https://www.who.int/publications/i/item/9789240083851
The report number in parentheses is only included when the document has one. When the author and the publisher are the same organization, as above, you drop the publisher to avoid saying it twice. Notice there is no mention of PDF anywhere.
Citing a journal article you have as a PDF
Cite it exactly as you would the article itself. It makes no difference that you read it as a downloaded file rather than on the journal's website:
APA 7TH
Kucsko, G., & Maurer, P. C. (2013). Nanometre-scale thermometry in a living cell.
Nature, 500(7460), 54-58. https://doi.org/10.1038/nature12373
MLA 9TH
Kucsko, Gerald, and Peter C. Maurer. "Nanometre-Scale Thermometry in a Living Cell."
Nature, vol. 500, no. 7460, 2013, pp. 54-58.
Citing a PDF in MLA 9th edition
Same principle: cite the underlying document with its normal container. MLA does allow one PDF-specific move that APA does not. When the file format genuinely matters to your reader, you may add a note like PDF download as an optional supplemental element at the very end:
United Nations. World Economic Situation and Prospects 2024. United Nations, 2024, www.un.org/development/desa/dpad/publication/world-economic-situation-and-prospects-2024. PDF download.
Most of the time you can leave that last element off. Include it when page numbers in your in-text citations only make sense against the PDF version, or when your instructor asks for it.
Citing a PDF in Chicago style
Chicago notes and bibliography treats the PDF like the printed document it represents. A report gets a bibliography entry like this:
World Health Organization. Global Tuberculosis Report 2023. Geneva: World Health Organization, 2023. https://www.who.int/publications/i/item/9789240083851.
The footnote version runs in normal order with commas: World Health Organization, Global Tuberculosis Report 2023 (Geneva: World Health Organization, 2023), 27. The page number at the end is the PDF page you are citing, which is one good reason to keep the file.
The awkward cases
LECTURE SLIDES YOUR INSTRUCTOR UPLOADED
APA: Instructor, A. (2026). *Week 4: Research methods* [Lecture slides]. University LMS. URL of the course page. The bracketed description does the work the PDF label cannot.
A SCANNED BOOK CHAPTER
Cite the chapter in the printed book it came from, with the page range from the scan: Author, A. A. (Year). Chapter title. In E. Editor (Ed.), *Book title* (pp. 33-51). Publisher.
A PDF SOMEONE EMAILED YOU THAT IS NOT ONLINE
APA: describe it honestly, for example Author, A. A. (2025). *Title of document* [Unpublished report]. No URL, because your reader cannot retrieve it. If it was truly private correspondence, cite it as a personal communication in the text only.
NO AUTHOR, NO DATE, NO PUBLISHER ANYWHERE
Ask yourself whether this PDF is strong enough to cite at all. A document nobody signed and nobody dated is a weak source. If you must use it, title moves to the author position and the date becomes n.d.
In-text citations for PDFs
One nice thing about PDFs: they usually have real page numbers, which web pages do not. Use them.
APA: Tuberculosis remains the world's second deadliest infectious disease (World Health Organization, 2023, p. 12).
MLA: The report calls the funding gap "the single largest obstacle" (United Nations 87).