Harmonic (Aristotle) vs Exa

A side-by-side look at scores, pricing and features — with RECATOOLS' ASEAN-aware verdict for each.

Harmonic (Aristotle) Math-reasoning AI from Robinhood CEO Vlad Tenev, using formal proofs t... Visit Exa Web search and retrieval API built for AI agents and apps Visit
RECATOOLS Score 7 / 10 7.7 / 10
Capability 8
Value for money 7
Ease of use 8
ASEAN readiness 6
API quality 8
Pricing Freemium Freemium
Free tier Free Aristotle chatbot app on iOS and Android (beta). 20,000 search requests per month on the free plan; startup and education grants of $1,000 in free API credits also available
Paid from Paid / enterprise API access for higher-volume use API search billed at $7 per 1,000 requests (as of March 2026 pricing update)
Has API
Open source
Free to use
Users
Founded 2023 2021
Maker Vlad Tenev, Tudor Achim
Verdict

What this is for: Solving and formally verifying mathematical problems using the Lean proof assistant to avoid hallucinated reasoning. Who this is for: Mathematicians, researchers, students and developers who need trust...

Exa earns its credibility through customer names, not just claims: Cursor, Notion AI, Cognition and OpenRouter all use it in production, and a $250M Series C at a $2.2B valuation (May 2026, led by a16z) backs that up. Th...

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Comparisons cover up to 4 tools. Scores are RECATOOLS editorial assessments; verify current pricing on each vendor's site.