Supported source types
You can add sources to your library in four ways:
- URL — paste any webpage, journal article, preprint, or online resource. Folio reads the page and extracts whatever metadata it can find.
- DOI — paste a DOI (e.g.
10.1000/xyz123) for journal articles. This gives the most reliable metadata because it pulls directly from the publisher registry. - ISBN — paste an ISBN for books. Folio looks up the edition and fills in title, authors, publisher, and year.
- PDF — upload a PDF directly. Folio extracts the text and attempts to identify the title, authors, and other metadata from the document itself.
What happens when you add a source
Metadata is extracted automatically: title, authors, year, journal or publisher, and abstract (when available). A citation is formatted in all supported styles so it's ready to insert the moment you need it. The source is immediately searchable in your library by title, author, year, or any keyword in the abstract.
Editing source metadata
Automatic extraction isn't always perfect — especially for PDFs or pages with unusual formatting. You can edit any field manually by opening the source and clicking into the metadata. Changes apply to all citations that reference that source across all your documents.
Supported citation formats
Folio supports five citation styles: APA 7, MLA 9, Chicago 17, IEEE, and Harvard. You can switch formats at any time and all citations update instantly — no manual reformatting.
Tips
- DOI lookup gives the most reliable metadata. If you have the DOI, use it.
- For PDFs, text extraction works best on non-scanned, text-based documents. Scanned PDFs with no selectable text may return incomplete metadata.
- You can add the same source more than once — Folio will warn you about duplicates so you can decide whether to keep or discard the new entry.