Save a paper, a PDF, or a catalogue record into Zotero with one click.
A green tab when a legal open-access copy of the paywalled paper exists.
Best for skipping the paywall when the author already posted the pdf
Reviewed 16 September 2026 · Prices checked the same day
4.7
48K reviews
Unpaywall, from Our Research, checks whether a paper has a legal open-access copy (author manuscript, repository, publisher OA). A tab on the page turns green when it does.
Chrome, Firefox, and Edge. Free, non-profit. It will not steal publisher PDFs. If the only copy is behind a login, the tab stays grey and you still need the library.
Pricing
free
$0
Free version
Full extension
Platforms
Chrome · Firefox · Edge
Leave it on. When it is green, take the PDF. When it is not, use the campus proxy or ask the librarian, not a pirate site.
Checked 2026-09-16
| Model | Free |
|---|---|
| What free actually includes | Full extension |
| Cheapest paid tier | $0 |
| Student pricing | None published |
Links from StudyApps include ref=studyapps.
Full extension Checked 16 September 2026.
Cheapest paid plan: $0. Prices checked 16 September 2026.
Skipping the paywall when the author already posted the PDF
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