alphaXiv vs ChatPDF

alphaXiv

• Following new machine learning and AI research on arXiv
• Asking questions about a paper while reading it
• Reading papers on an iPhone or iPad
• Developers who want paper search inside a coding agent

ChatPDF

• Students and researchers who want quick answers from a paper or textbook chapter
• Asking questions across several files kept in one folder
• Trying a document chat tool without creating an account
• Turning course material into flashcards or slides

alphaXiv

• The site has no public pricing page; plans and prices are shown on the Subscription/Usage page in account settings.
• The free plan limits the assistant to preset models with strict usage limits; choosing any model needs alphaXiv Pro.
• alphaXiv Go raises limits on open-source models only and does not include Pro-tier models.
• There is an iPhone and iPad app and a Chrome extension; the site lists no Android or desktop app.

ChatPDF

• The website shows Plus prices only in an upgrade dialog and sets them per visitor; the prices here are US App Store in-app purchases, and web checkout may differ.
• The free plan covers 2 documents a day, and the site's limits cap free use at 20 messages a day and files of 120 pages or 10 MB.
• AI Research summaries are built from abstracts, and chatting with a full paper works only for open-access papers.
• The best model is reserved for Plus; ChatPDF says it routes queries between GPT-4o and GPT-4o-mini.

alphaXiv

Trending feed

A feed of research curated by what the community is reading, with a short summary for each paper and a view tailored to your research interests.

AI assistant

Answers research questions and produces literature reviews grounded in the underlying papers, and can point to who is working on a topic.

Paper reader

Read a paper with highlights and personal notes, chat with the assistant about a highlighted section, and add other papers to the conversation with an @ mention.

AI visual blogs

Turns a paper into a blog-style explanation with figures, equations and key insights in one click, readable in several languages.

Library

Bookmark papers to read later with BibTeX citations generated automatically, and upload a paper that is missing to get the same assistant and overviews.

MCP server

Gives AI agents 19 tools to search and read papers, analyze PDFs, explore paper codebases and find researchers. It works with clients such as Claude Code, Cursor and VS Code.

ChatPDF

Chat with documents

Ask questions about a PDF, Word, PowerPoint, Markdown or text file with the chat and the document side by side. Clickable citations scroll to the passage an answer came from.

Multi-file folders

Put files in a folder to ask questions across all of them in one conversation. Folders and saved chat history need a free account.

AI Research

Ask a question to find academic papers and get a summary with citations, built from the papers' abstracts. Filters narrow results to recent or influential work.

YouTube and website chat

Paste a YouTube or website link to ask questions about it. Video answers include clickable timestamps and an interactive transcript.

Flashcards, slides and writing

Makes flashcards that export to Anki, Quizlet, Brainscape or CSV, and slides that export to PowerPoint. The AI Writer drafts text with citations and exports to Word or Markdown.

Developer API

A backend API adds PDFs by URL or file upload and answers questions about them, with optional page references. API files are limited to 2,000 pages or 32 MB.

alphaXiv

• Free$0

  For occasional reading and quick follow-up questions: chat with any arXiv paper on preset models, under strict usage limits.

• alphaXiv Go$8

  per month

  Higher limits on lower-cost open-source models; Pro-tier models are not included. $5 a month for student researchers.

• alphaXiv Pro$20

  per month

  Higher assistant usage limits, a choice of any model, longer context windows and early access to beta features.

• alphaXiv Pro 5× usage$100

  per month

  The Pro plan with 5 times the assistant usage and priority routing.

ChatPDF

• Free$0

  2 documents and 20 messages a day, with files of up to 120 pages or 10 MB and folders of up to 5 files.

• Plus$14.99

  per month on the US App Store; $89.99 for the yearly plan

  Unlimited questions and documents, files of up to 2,000 pages or 150 MB, 50 PDFs per folder and the higher-quality model.

alphaXiv

• Education

  alphaXiv Go at $5 a month for student researchers

  Linking a recognized academic email, such as an .edu address, to the account lowers alphaXiv Go from $8 to $5 a month.

ChatPDF

• Annual discount

  About 50% off with the yearly plan

  On the US App Store the yearly Plus plan is $89.99 against $14.99 a month. That works out to about $7.50 a month, half the monthly rate.