Rayyan
Fast, collaborative screening for systematic reviews — with a generous free tier.
Tier 2 ToolsFreemium
Research Database Directory
Every research database, reviewed.
PubMed Central (PMC)
The free full-text archive behind PubMed — biomedical papers you can actually read.
Tier 2 Open AccessFree
Google Dataset Search
Google for datasets — one search box across millions of data repositories.
Tier 2 ToolsFree
ORCID
A unique ID for every researcher — the thread that ties a career's work together.
Tier 2 ToolsFree
Retraction Watch
The database of retractions — know when a paper has been pulled.
Tier 2 Open AccessFree
Elicit
The AI research assistant built for evidence — search, screen, and extract at scale.
Tier 2 ToolsFreemium
Consensus
Ask a research question, get an evidence-based answer from the literature.
Tier 2 ToolsFreemium
Research Rabbit
A free discovery engine that maps a field from the papers you already like.
Tier 2 ToolsFree
OpenAIRE
Europe's open scholarly graph — publications, data, software, and funding, linked.
Tier 2 Open AccessFree
Unpaywall
The one-click route to a legal free version of almost any paper.
Tier 2 ToolsFree