Free, high-accuracy deduplication for systematic reviews.
At a Glance
| Publisher | University of Edinburgh |
| Coverage | a deduplication tool for reference sets, available as an R package and a no-code web app |
| Access | free |
| Regional | global; works on any RIS/reference export. |
Our Take
ASySD (Automated Systematic Search Deduplicator) is the free, rigorous answer to the duplicate problem in systematic reviews — tested on datasets from roughly 1,845 to 79,880 citations with 0.95–0.99 sensitivity, and usable either as an R package or a web app that requires no coding. For review teams without a budget for commercial dedup, it’s the standout. It does one job, so it sits alongside your reference manager and screening tools rather than replacing them. Use it when a review needs audit-grade deduplication for free; pair it with Zotero for library management and Rayyan or Covidence for screening.
Power Tips
- Run ASySD on your combined multi-database export for higher-accuracy dedup than a reference manager’s built-in check, keeping source tags for auditable PRISMA counts (Issue 3)
- use the no-code web app if you don’t work in R — the accuracy is the same.
Alternatives & Complements
Deduklick · Zotero · EndNote · Rayyan.
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