Research & Search

C

ChatPDF

Chat with uploaded documents (PDF, Word, PowerPoint, text). Free plan allows 2 documents a day; Plus price is not shown on official pages, so confirm on the site.

C

Consensus

AI search engine that answers questions from scholarly papers, with a citation on each sentence. Free plan; Pro is $144 a year (about $12 a month) or $20 monthly.

E

Elicit

AI research assistant that searches 138M+ papers, summarizes them, extracts data and writes cited reports and systematic reviews. Free Basic plan; Pro reported at $49 a month billed annually.

F

Felo AI

AI search with cited sources, plus slides and a research agent on one credit balance. Free plan; Pro is $12.50 a month billed annually (Reported), $14.99 monthly.

G

Gemini Notebook

Google's AI research notebook (formerly NotebookLM). Answers questions from your own sources with citations. Free plan; higher limits come with Google AI plans, with Plus reported at $4.99 a month.

H

Humata

Answers questions about uploaded documents with citations. Free has 60 pages a month; Expert is $9.99 a month (monthly billing, annual not listed).

K

Kagi

Paid, ad-free search engine with an AI assistant. Plans from $5 a month; a free trial of 100 searches. Annual billing is 10% off.

L

Liner

AI search and research tool with cited answers, paper search and writing. Free plan has ads; Pro is $14.99 a month billed annually ($17.99 monthly).

O

Otio

AI research workspace for chatting with PDFs, videos and web pages with page-level citations. Lite is $7 a month billed annually ($84 a year).

P

Paperguide

AI research workspace for paper search, chat with PDFs, literature and systematic reviews, and writing; free plan, paid from $12 per seat a month billed annually.

P

Paperpile

Reference manager with Google Docs and Word plugins, a browser extension and mobile apps. No free plan after a 30 day trial; Regular is $4.15 a month billed annually.

P

Perplexity Pro

AI search and assistant that answers with cited sources. Free plan; Pro adds higher Research, file-upload and browser-agent limits. Pro price reported at $200 a year or $20 monthly.

R

Recall

AI knowledge base that saves articles, videos, podcasts and PDFs, then summarizes them and lets you chat with them. Free plan; Plus is $10 a month billed annually.

R

ResearchRabbit

Literature discovery tool that maps papers related to your seed articles; Free allows 50 seeds. ResearchRabbit+ starts at $10 a month (annual plan label; $12.5 monthly label).

S

Scholarcy

Turns research papers into summary flashcards with highlights and references; web app and browser extensions. Free plan available; paid plan prices not readable on the vendor page.

S

SciSpace

AI research assistant for literature search, paper chat and cited writing on web, Chrome and mobile. Free plan; paid plans start at $12 a month billed annually (Reported).

S

Scite.ai

AI research platform with an Assistant, full-text citation search and Smart Citations. Basic is $12 a month billed annually ($20 monthly); no free plan, 7-day trial.

U

Undermind

AI research assistant for scientific literature with deep search and cited answers, also usable inside Claude and ChatGPT. Free plan; Pro is $16 a month billed annually.

Y

You.com

Web search, content, answer and research APIs for AI apps, with a free tier of 100 queries a day and pay-as-you-go pricing from $5 per 1,000 Web Search calls.