Connected Papers vs ResearchRabbit vs Litmaps: which citation map fits your stage?

This comparison is for students and researchers choosing a literature mapping tool for a thesis or review. It is part of our guide to the best AI for deep research. Every product fact was checked on the vendor's own page in November 2026 or is marked for verification.

What is a citation map tool?

A citation map tool takes one or more papers you already trust and shows you other papers linked to them through references, citations or similarity, usually as a graph. It automates what librarians call citation searching or snowballing: going backward through reference lists and forward through papers that cite your set. For the manual method, see citation snowballing.

The three tools differ in what a link means:

• Direct citation: paper B is in paper A's reference list.
• Co-citation: papers A and B are both cited by a third paper.
• Bibliographic coupling: papers A and B both cite the same third paper.

A map built from direct citations shows lineage. A map built from co-citation and coupling shows similarity, so it can surface papers that never cite each other.

The three tools at a glance (checked November 2026)

Prices change and vary by country; ResearchRabbit and Litmaps both mention country discounts [3], [5].

Connected Papers: what it does well

Connected Papers is a free-to-start tool that builds a graph of a few dozen papers most similar to an origin paper, based on shared citations and references. It does not draw citation lines between papers. It places similar papers close together, so clusters show sub-topics.

Its strengths:

• Speed from one paper. Paste a DOI or title and you get a map with no account and no setup. That is ideal in the first week of a topic.
• Similarity, not just citation. Because it uses co-citation and bibliographic coupling [1], it finds papers that sit in the same conversation even if neither cites the other.
• Prior works and derivative works. Prior works are older papers frequently cited by papers in the graph, often the field's foundations. Derivative works are newer papers that cite many papers in the graph, often recent reviews .
• Multi-origin graphs. Adding a second origin paper narrows the graph to papers related to both .

Where it stops: each graph is a snapshot from a fixed seed set, the free cap limits how many you can make in a month, and coverage depends on the Semantic Scholar corpus, which is thinner for books and some humanities work.

ResearchRabbit: what it does well

ResearchRabbit is a literature discovery app where you add papers to collections and follow links to related work, building a map as you browse. People often search for it as "Research Rabbit app" or "rabbit research".

Its strengths:

• Generous free plan. Free Forever includes unlimited searches across 310M+ articles, an unlimited library and collections, and sharing [3].
• Exploration that compounds. Each paper you add changes the recommendations, so a collection becomes a running model of your topic [4].
• Collections you can share with a supervisor or co-author at no cost [3].

Since May 2025 ResearchRabbit has been developed with Litmaps: Litmaps announced it had acquired ResearchRabbit, and a rebuilt ResearchRabbit launched in October 2025 "thanks to our partnership with Litmaps" [7], [8]. The rebuild added the RR+ paid tier with up to 300 seed articles, multiple projects, advanced search controls and Signals alerts [3].

Where it stops: the free plan caps seeds at 50 [3], and a browsing tool makes it easy to wander. Record which papers you started from and why you kept each one, or you will not be able to report the search later.

Litmaps: what it does well

Litmaps is a literature mapping tool that builds saved maps from seed papers and monitors your topic for new publications. Its homepage lists four jobs: Discover, Visualize, Share and Monitor [9].

Its strengths:

• Many seeds, saved maps. Pro allows unlimited inputs and unlimited maps, so one map can hold a whole thesis topic [5].
• Alerts. Free sends a monthly summary; Pro sends daily or configurable alerts [5]. For a PhD that runs three years, this is the feature that matters most.
• A readable layout. Maps are commonly described as placing newer papers to the right and more-cited papers higher, so you can spot both classics and recent work .
• Team plan for labs that share maps [5].

Where it stops: the free plan is small (100 articles per map and up to 20 inputs) [5], and the Education discount needs an academic email.

Which tool fits which stage?

Choose by what you are doing this week.

A worked example

Example (invented, for illustration). A master's student studying "sleep and exam performance in university students" has three good papers.

1. She puts the most-cited one into Connected Papers and gets a graph of about 40 papers. Two clusters stand out: sleep duration studies and chronotype studies. She notes 8 new candidates.
2. She creates a ResearchRabbit collection with the 3 seeds plus the 8 and browses later work. She keeps 9 more, for 20 in total.
3. She exports the 20 to her reference manager and builds a Litmaps map from them, with alerts on. Over the next four months, alerts bring 3 new relevant papers.

Her methods note says: "Citation searching from 3 seed papers using Connected Papers and ResearchRabbit (October 2026) identified 17 additional records; Litmaps alerts identified 3 more (to February 2027)." That sentence is what a reviewer needs.

Do citation maps work for a systematic review?

They help, but they don't replace database searching. Systematic review guidance treats citation searching as a supplementary method alongside database searches [10]. PRISMA 2020 asks you to report citation searching among "other methods" in your flow diagram [11].

To make map output reportable:

1. Record the seed papers and the date.
2. Record each tool and setting used.
3. Export the candidate list (RIS or CSV) before screening.
4. Screen candidates with the same criteria as database results.
5. Count them in the "other methods" side of the PRISMA diagram.

Citation Map in AI for Research

AI for Research has its own Citation Map, built for this reportable kind of snowballing. It costs 0 credits.

• Seed paper view: references and citing papers of one paper, from OpenAlex with Semantic Scholar as fallback, shown as a graph with years across and as a list.
• Snowballing rounds: add papers to a set, expand the next round from the whole set, and see candidates ranked by how many set papers link to them. That ranking is a quick way to spot the papers your set agrees are central.
• Reviews that cite your set: it finds reviews and meta-analyses citing your papers, often the fastest route to a complete reference list.
• Export: RIS and CSV, ready to upload into a Systematic Review project, where duplicates are removed by DOI, PMID and title and the PRISMA 2020 diagram is drawn from live counts.

Honest limits: Citation Map shows direct citation links, not a co-citation similarity layout like Connected Papers, and it has no new-paper alerts like Litmaps or ResearchRabbit+. Pair it with Find Papers for keyword search. Free plans get 45 credits a month for AI work; mapping itself is free. See pricing.

FAQ

Is Connected Papers free?

Yes, with a monthly cap. Independent reviews in 2026 report that the free plan allows five graphs a month with all main features, and that paid Academic and Business plans remove the cap. Its pricing page did not load for our checker in November 2026, so confirm the current cap and prices on connectedpapers.com before you plan a big search.

Is ResearchRabbit free?

Yes. As checked on its pricing page in November 2026, the Free Forever plan costs $0 and includes unlimited searches, an unlimited library and collections, sharing, and up to 50 seed articles. ResearchRabbit+ costs $10 a month on the annual plan or $12.50 monthly, with up to 300 seed articles, multiple projects and Signals alerts. Country discounts are available.

Which is better, Connected Papers or Litmaps?

Connected Papers is better for a quick, one-paper look at a field: one seed, one similarity graph, no setup. Litmaps is better when you will keep coming back: it saves maps, accepts many seed papers on Pro, and sends alerts about new papers. For a single afternoon of exploration use Connected Papers; for a thesis-long topic use Litmaps or ResearchRabbit.

What is the difference between ResearchRabbit and Connected Papers?

Connected Papers draws a graph of papers similar to one or a few origin papers, using shared citations and references. ResearchRabbit is a browsing tool: you build collections and follow links to related, earlier and later work step by step, so the map grows as you explore. Since 2025 ResearchRabbit has been developed with Litmaps.

Do citation map tools replace a database search?

No. Citation maps find papers connected to the ones you already have, so they inherit your starting set's blind spots. Papers that no one in your set cites, new papers with few citations, and work in other languages are often missed. Use a map after a keyword or database search, and record it as citation searching in your methods.

Next steps

• Learn the manual method behind all three tools in citation snowballing.
• Compare search and answer tools in the best AI for deep research.
• Read our Consensus AI review and SciSpace review.

Sources

1. Connected Papers. About. https://www.connectedpapers.com/about (checked November 2026; page content did not load for our checker, method described as quoted in library guides)
2. Connected Papers. Pricing. https://www.connectedpapers.com/pricing (checked November 2026; plan details did not load for our checker)
3. ResearchRabbit. Pricing. https://www.researchrabbit.ai/pricing (checked November 2026)
4. ResearchRabbit. Homepage. https://www.researchrabbit.ai/ (checked November 2026)
5. Litmaps. Pricing. https://www.litmaps.com/pricing (checked November 2026)
6. Loyola Marymount University Library. AI research tools: Connected Papers. https://libguides.lmu.edu/AIresearchtools/CP (checked November 2026)
7. ResearchRabbit. Welcome to the new ResearchRabbit (20 October 2025). https://www.researchrabbit.ai/releases/welcome-to-the-new-researchrabbit (checked November 2026)
8. IT Brief New Zealand. Litmaps acquires ResearchRabbit, raises $1 million for AI. https://itbrief.co.nz/story/litmaps-acquires-researchrabbit-raises-1-million-for-ai (checked November 2026)
9. Litmaps. Homepage. https://www.litmaps.com/ (checked November 2026)
10. Lefebvre, C., et al. Chapter 4: Searching for and selecting studies. In Higgins, J. P. T., et al. (eds.), Cochrane Handbook for Systematic Reviews of Interventions, version 6.5. https://www.cochrane.org/authors/handbooks-and-manuals/handbook/current/chapter-04
11. Page, M. J., et al. (2021). The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. BMJ, 372, n71. https://doi.org/10.1136/bmj.n71