PROSPERO versus OSF registration comes down to scope: PROSPERO is the dedicated register for systematic reviews with a health-related outcome and applies a completeness check, while OSF is an open, flexible repository that accepts any review type and publishes immediately. Most health reviews register on PROSPERO; reviews outside health, and many scoping reviews, use OSF.
Why you register at all, and why the venue matters
Both platforms do the same essential job: they timestamp your methods publicly before you see the evidence, which is what protects your review from quiet method changes and selective reporting. The difference is in what each accepts, how fast it publishes, and how much structure it imposes. Picking the wrong venue rarely sinks a review, but registering somewhere that does not accept your review type wastes time you could have spent on the search strategy. The decision belongs in your protocol, alongside your eligibility criteria.
Where PROSPERO wins
PROSPERO is purpose-built for systematic reviews, so its structured form mirrors a good protocol field by field and nudges you to complete every method decision. Its completeness check, while it adds a wait, lends the registration credibility that some journals and reviewers specifically look for. If your review has a health-related outcome and fits a recognised review design, PROSPERO is usually the default, and our step-by-step on registering on PROSPERO walks through the form. The structure is the quiet advantage here: because the form demands named databases, explicit eligibility rules, and a committed risk of bias instrument, it is hard to register a vague plan, and that friction protects you from yourself later in the review.
Where OSF wins
OSF accepts what PROSPERO turns away. Scoping reviews, methodological reviews, reviews with no health outcome, and reviews already part-way through all have a home there. It publishes immediately rather than waiting on a check, and it doubles as a project workspace where you can store your data extraction files, code, and search logs alongside the registration. That flexibility suits a scoping review or any review outside the clinical mainstream.
The immediacy is a genuine practical difference, not a footnote. A team that needs a timestamp on its methods today, perhaps because a funder or a thesis committee requires registration before work starts, can create and publish an OSF entry in an afternoon, whereas PROSPERO’s completeness check sits between submission and a public record. The trade-off is that immediacy with no check also means OSF will happily publish an underdeveloped plan, so the discipline that PROSPERO enforces externally has to come from you. For multi-method projects, the workspace side is the deciding factor: keeping the protocol, the documented search, and the analysis files in one versioned place is something a register alone cannot offer.
How to choose between them
Before the two-question test, settle one thing people often get wrong: you do not choose a venue to make the review look more rigorous. The venue does not add rigour; the protocol does. A weak plan registered on PROSPERO is still a weak plan, and a strong plan on OSF is still strong. The choice is purely about fit, speed, and whether you need a workspace, so resist the instinct to default to the better-known register when your review type does not actually suit it.
Ask two questions. First, does your review have a health-related outcome and fit a design PROSPERO accepts? If yes, PROSPERO is the stronger default. Second, is your review a scoping rather than a systematic review, outside health, or already underway? If yes, OSF is the practical choice. You do not register the same review in both places; pick one venue and cite its identifier. Whichever you choose, the harder work is still the framing of the question and the criteria behind it.
A decision table for the common review types
The two-question test resolves most cases, but it helps to see how it lands for the review designs people actually run:
- A randomised-trial review of a drug or therapy with a clinical outcome goes to PROSPERO, the default for anything with a health-related outcome.
- A scoping review mapping a literature goes to OSF, because PROSPERO does not register scoping reviews at all.
- A review in education, economics, or social policy with no health outcome goes to OSF, which accepts any review type.
- An umbrella review of existing reviews with a health focus can register on PROSPERO; the same review outside health uses OSF.
- A review already part-way through, where you missed the prospective window, has a home on OSF, since PROSPERO requires registration before data extraction.
Whichever venue applies, the entry is only as strong as the underlying protocol, so the real preparation is the same on both platforms.
What each platform does not do
Knowing the limits prevents misplaced expectations. PROSPERO is not a workspace: it records your plan but does not host your data, screening records, or analysis files, so you still need somewhere to keep the extraction forms and search logs that make the review reproducible. OSF, by contrast, hosts all of that but applies no completeness check, which means a thin or hurried OSF entry carries none of the credibility a structured PROSPERO record signals. Neither platform is peer review, and neither guarantees a journal will accept the review; both simply create the public, dated record that lets a reader compare your final PRISMA 2020 report against what you set out to do.
After registration: the rule is the same on both
Neither registration is frozen. As your review progresses you may need to update the record, and both platforms keep prior versions visible. The principle does not depend on the venue: record every change with a date and a reason, exactly as we describe in amending a protocol. A transparent history of changes is what gives either registration its value.