Direct comparison
Gold vs Green vs Diamond vs Hybrid OA Compared
Gold, green, diamond, and hybrid open access compared: who pays, embargo rules, licensing, and why hybrid OA draws 'double-dipping' criticism.
Side-by-side comparison
| Dimension | Gold OA | Green OA | Diamond OA | Hybrid OA |
|---|---|---|---|---|
| Core mechanism | Publisher's version of record made freely available at the publisher's own site, immediately at publication | Author self-archives a manuscript version in an institutional or subject repository, separate from the publisher's site | Publisher's version of record made freely available at the publisher's own site, with no fee to either side | A subscription journal makes individual articles openly available at its own site when the author pays a per-article fee; the rest of the issue stays paywalled |
| Who pays | Author, funder, or institution (APC) — though an APC is not always required | No publishing fee; institution/researcher funds repository infrastructure | No one directly — subsidized by a society, university, library, or consortium | Author/funder/institution pays an APC, on top of the journal's existing subscription revenue |
| Version made available | Version of record | Usually the peer-reviewed author accepted manuscript, not the typeset version of record | Version of record | Version of record |
| Typical embargo | None | Historically 6-12 months under publisher policy; funder mandates (NIH from July 2025, UKRI since April 2022) now require zero embargo for compliant deposits | None | None |
| Typical license | CC BY common, especially where funder-mandated | Varies by publisher self-archiving policy; may lack a formal reuse license beyond deposit permission | CC BY common, especially for DOAJ-listed titles | CC BY available for the individual paid-OA article |
| Plan S / cOAlition S compliance | Compliant | Compliant if zero embargo and an open license apply (e.g. via a funder rights-retention strategy) | Compliant; explicitly favored | Not compliant except via a registered Transformative Journal or Transformative Agreement |
| Common criticism | APCs can be a real cost barrier without funder or institutional support | Readers often get an out-of-date, non-typeset manuscript; embargoes historically delayed access | Sustainability risk — many titles depend on volunteer labor and fragile funding | "Double dipping" — the publisher can collect both subscription revenue and the article's APC |
| Who typically uses it | Authors with dedicated OA funding, publishing in fully-OA journals or platforms | Authors meeting a funder mandate without separate OA funding, in a subscription journal | Scholarly societies, university presses, and community/consortium-run journals | Legacy subscription journals transitioning to OA, often under a Read & Publish agreement |
Common questions
FAQ
Is hybrid open access the same as gold open access?+
Not quite. Both make the publisher's version of record immediately free at the point of publication, and some definitions of gold OA -- including CASRAI's own Dictionary entry -- technically count hybrid as a subtype, since an article can be gold OA whether or not an APC was paid. This comparison treats them separately because hybrid's economics (an APC layered on top of ongoing subscription revenue) and its funder treatment (restricted under Plan S except via a Transformative Agreement) differ sharply from a fully open, APC-only or subscription-free journal.
Does green open access satisfy funder open access mandates?+
Often, but only if the deposit meets the funder's specific terms. NIH's Public Access Policy (for manuscripts accepted from July 1, 2025) and UKRI's open access policy (journal articles submitted from April 2022) both require the author accepted manuscript to be deposited immediately, with no publisher embargo. A green deposit still carrying a 6-12 month publisher embargo will not satisfy either policy.
Why isn't diamond open access more widely used if it's free to authors?+
It exists at real scale -- diamond titles are the largest single category by journal count in the Directory of Open Access Journals -- but individual diamond journals tend to be smaller and less commercially visible than large gold or hybrid venues, so they account for a much smaller share of total published article output. Sustainability (reliance on volunteer labor and uncertain long-term funding) is also a recognized structural challenge.
What is "double dipping" in hybrid open access?+
The criticism that a publisher can collect both ongoing subscription revenue for a hybrid journal and a separate APC for each individually-open article within it -- effectively being paid twice for output that a fully open or diamond journal would generate only one revenue stream from. It is the central reason cOAlition S excludes hybrid from Plan S compliance outside a registered Transformative Agreement.
