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R Discovery vs Semantic Scholar

Two fact sheets from our own research, side by side — pricing, platforms, API access and status re-checked by us rather than quoted from the vendors. R Discovery publishes a starting price ($12); Semantic Scholar does not. Both have a free tier. Only Semantic Scholar ships a public API.

R DiscoveryRecommends and summarizes research papers, chats with PDFs, and reads papers aloud, built by Cactus Communications.Semantic ScholarFree search across 237M research papers, with citation context, one-line summaries and an open scholarly API.

Side by side

FactR DiscoverySemantic Scholar
CategoryAcademic Search & Literature ReviewAcademic Search & Literature Review
Pricing modelFreemiumFree
Starts at$12 month—
Public APINoYes
PlatformsWeb, iOS, Android, Chrome ExtWeb, API
CompanyCactus CommunicationsAllen Institute for AI (Ai2)
Launched—2015
Last verifiedSep 1, 2026Sep 6, 2026

What our research says

R Discovery

R Discovery is built around the daily habit of keeping up with a field: it recommends papers based on what you've already read, then lets you interrogate a PDF instead of skimming it cold. The free tier is usable on its own, but the features researchers actually want, literature review drafts and unlimited PDF chat, sit behind the $12/month Prime plan.

Pros

  • Personalized paper feed based on reading history across a large index
  • Chat directly with a paper's PDF instead of just searching its abstract
  • Generates a first-draft literature review from selected papers
  • Audio playback for papers, useful for reading on the move

Cons

  • Heavier AI features (literature review, unlimited PDF chat) require the paid Prime tier
  • Recommendation quality depends on how much reading history the account has built up
  • No API for pulling data into other research tools

Semantic Scholar

The most useful free academic search on the open web, and the only one that also hands you its corpus and its API. Coverage is broad but metadata quality varies by publisher, so it will not replace Scopus or Web of Science for a systematic review. Treat the TLDR summaries as triage, not as a reading substitute.

Pros

  • 237M+ papers searchable without an account
  • TLDR one-line summaries generated per paper
  • Semantic Reader shows citation context inline
  • Free Academic Graph API and the open S2ORC corpus

Cons

  • Metadata and full-text availability vary by publisher
  • No systematic-review tooling such as PRISMA exports
  • Non-profit funding means feature pace is not commercial

Which one fits

Choose R Discovery if you need

  • Researchers who want a personalized feed of new papers in their field
  • Skimming a paper's findings via chat before deciding to read the full text
  • Non-native English speakers who need abstracts translated

Choose Semantic Scholar if you need

  • screening a literature list before you read
  • tracing who cited a paper and in what context
  • developers who need free bulk scholarly metadata

More comparisons

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