alphaXiv
Swap arxiv.org for alphaxiv.org in any paper link and get an AI assistant, plain-language blog summary, and line-by-line discussion on top of the same paper, free.
Overview
alphaXiv turns every arXiv paper into a live discussion with an AI assistant attached, and the entry trick is absurdly simple: swap arxiv.org for alphaxiv.org in any paper URL and you land on the same paper with a full reading layer on top. That layer includes an Ask AI assistant grounded in the paper's actual text (so answers cite the paper instead of hallucinating from general training data), a line-by-line comment thread anyone can attach to a specific equation or figure, and an auto-generated blog-style summary that turns a dense methods section into a 1,500-to-2,500-word plain-language writeup with the original diagrams inlined. Started inside Stanford and grown into a community-supported project, it now also ships a browser extension and mobile app so the same AI overlay works on any PDF, not just arXiv links, plus an MCP server for pulling paper context into other AI workflows. Reading, searching, and using Ask AI require no account at all, and posting a comment only needs a free email signup. As of mid-2026 there is no paid tier, making it a genuinely free way to cut through a dense paper in minutes instead of hours.
Key Features
- Ask AI assistant grounded in the paper's own text
- Line-by-line comment threads on equations, figures, and passages
- Auto-generated plain-language blog summary of any paper
- Browser extension and mobile app for reading and chatting on any PDF
- MCP server for pulling paper context into other AI tools
- • Completely free with no paywall, signup, or feature gating
- • AI answers are grounded in the actual paper, which cuts down on hallucinated citations
- • The URL-swap trick means zero learning curve to get started
- • Limited to arXiv and bioRxiv preprints, no paywalled journals
- • Community discussion is dense for popular ML papers but thin in long-tail fields
- • Free model with no announced business plan, worth watching for future pricing changes
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