Research Rabbit

Yes. Research Rabbit's Free Forever tier includes unlimited searches across 280+ million articles, unlimited collections, collaboration features, library uploads, and the ability to start from up to 50 seed articles per project. It has always been free and the team has publicly committed to keeping a free tier. There's now an optional RR+ premium tier for researchers who want more advanced search features, with country-based pricing to ensure affordability worldwide.

You start by adding a few seed papers you know are relevant to your topic — these can be imported from Zotero, uploaded as PDFs, or searched directly. Research Rabbit then builds an interactive visual graph showing related work, earlier work that influenced your seeds, and newer work that cites them. The visualization makes it easy to spot research clusters, see influential papers at a glance, and jump between related lines of inquiry. It's the fastest way to map an unfamiliar research area.

Both tools visualize citation networks around seed papers. Research Rabbit's advantage is a more interactive interface, unlimited seed collections, Zotero integration, collaboration features, and an explicit commitment to staying free forever. Connected Papers is more minimalist and limits free users to a few searches per month before requiring payment. For most researchers doing ongoing work across multiple projects, Research Rabbit's free tier is the better fit.

Yes. Research Rabbit integrates directly with Zotero so you can import your existing library or sync specific collections. This makes it easy to start a graph from papers you've already been reading. Mendeley integration is less direct but you can export RIS files from Mendeley and import them into Research Rabbit. The Zotero integration is the main workflow for most users who already have an established reference library.

Research Rabbit uses AI and citation graph algorithms to surface related papers and influential work. It's less focused on conversational AI than tools like Elicit or Consensus — there's no PDF chat or systematic review workflow. Instead, it focuses on doing one thing extremely well: discovering papers through visual citation relationships. The AI is embedded in the ranking and recommendation system rather than exposed as a chat interface.

RR+ is Research Rabbit's premium tier for researchers doing large-scale literature discovery. It adds more advanced search features, deeper citation connections, and enhanced workflow tools. Importantly, RR+ uses country-based pricing — over 100 countries qualify for significant discounts to make the premium tier accessible to researchers worldwide. The Free Forever tier remains fully usable without upgrading, so RR+ is strictly for power users who want extras.

It's a great discovery tool for the scoping phase of a systematic review — mapping the field, finding seed papers, and identifying key citations. For the full PRISMA workflow (screening, extraction, quality assessment), you'll need dedicated tools like Rayyan, Covidence, or Elicit. Many researchers use Research Rabbit at the start of a review to discover the literature, then export to Zotero and run the formal screening process elsewhere.

Research Rabbit indexes 280+ million articles across most academic fields, though coverage is strongest in computer science, biomedicine, and STEM fields (similar to Semantic Scholar, which powers much of its data). Humanities and non-English research have weaker coverage. For niche humanities topics, supplement Research Rabbit with field-specific databases and Google Scholar.