Comparison

AI Agent Index vs Explore | alphaXiv

AI Agent Index lands on Depends, and Explore | alphaXiv lands on Worth it.

AI Agent Index

aiagentindex.mit.edu

Depends

Confidence: Medium

Use it if you research, procure, or govern AI agents and want free, documented capability and safety data.

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Explore | alphaXiv

Worth it

Confidence: Medium

Use it if you regularly read arXiv preprints and want discussion threads plus AI-assisted reading . the core is free.

Read the full report

AI Agent Index versus Explore | alphaXiv
Compare	AI Agent Index	Explore \| alphaXiv
Verdict	Depends	Worth it
Best for	AI safety and policy researchers	AI/ML researchers tracking preprints
Who it's not for	Buyers wanting reviews, ratings, or pricing before choosing an agent	Anyone needing paywalled journals (Nature, IEEE) . preprints only
Privacy	No known public vulnerabilities found in the sources reviewed.^¹	No known public vulnerabilities found in the sources reviewed.¹²
Public sentiment	No independent user reviews surfaced; public discussion is researchers and practitioners citing or amplifying the paper.¹⁰	Early users praise it as a clean way to read and openly discuss preprints, with coverage limits the main caveat.
Biggest gotcha	Easy to confuse with commercial site . different product, different owner.^⁹	Official pricing page absent; free-tier limits described only by third parties¹⁵

Pick AI Agent Index when

AI safety and policy researchers
Procurement teams vetting agent vendors
Security teams cataloguing agent risks
Analysts tracking the agent landscape

When AI Agent Index is not a fit

Buyers wanting reviews, ratings, or pricing before choosing an agent
Teams expecting a searchable, current tool directory
Small teams who just need a quick tool recommendation
Anyone needing vendor contact, trials, or support

Pick Explore | alphaXiv when

AI/ML researchers tracking preprints
Grad students reading papers
Authors seeking paper feedback
Engineers following AI research

When Explore | alphaXiv is not a fit

Anyone needing paywalled journals (Nature, IEEE) . preprints only
Non-preprint fields: law, clinical medicine, humanities
Anyone building formal citation libraries . use Zotero instead
Buyers wanting a governed, enterprise research platform

Sources

The 2025 AI Agent Index (official site)aiagentindex.mit.edu
official
The 2025 AI Agent Index (paper)arxiv.org
official
ACM publicationdl.acm.org
official
MIT Sloan: Agentic AI, explainedmitsloan.mit.edu
news
Cambridge: Most AI bots lack basic safety disclosurescam.ac.uk
security
IETF agent security benchmark (cites the index)ietf.org
security
Kynver NIST comment citing the indexkynver.com
security
Mallory.ai: MIT index warns of opaque, unsafe agentsmallory.ai
security
The AI Agent Index (commercial directory, name lookalike)theaiagentindex.com
review
Reddit: MIT AI Agent Index Released Todayreddit.com
review
alphaXiv: Explorealphaxiv.org
official
Privacy Policy - alphaXivalphaxiv.org
security
AlphaXiv: The New Hub for Open Scientific Dialoguespectrum.ieee.org
news
alphaXiv Review 2026: AI Comments on arXiv Paperstoolcenter.ai
review
alphaXiv Review . Features, Pricing & Alternatives (2026)theworkflowfinder.com
review
How I use AlphaXiv to read research papersmarkptorres.com
review