Option A: Consensus: orders papers from easy to hard
Best when: The subject has academic papers
What it does: Consensus ranks papers; you check each item exists
Strong at: An academic search engine over peer-reviewed literature
Limit: Order and level are not proven by the page
Free plan: Yes, limited (10 Pro messages, 3 Deep reviews per month)
Option B: Perplexity: drafts a reading path with links
Best when: The subject is not mainly academic
What it does: Perplexity drafts the path; you open every link
Strong at: Searches the web and names its sources
Limit: Invented items are possible, so every link needs opening
Free plan: Yes
Option C: Claude: orders the items you already hold
Best when: You already own most of the material
What it does: Claude groups and drafts reasons; you check each one
Strong at: Works only from material you already have
Limit: Levels judged from titles can be wrong; check each one
Free plan: Yes, limited (5-hour session and weekly caps)