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Best for · October 2026

Best AI model for hard reasoning

When the task is genuinely hard, price stops being the constraint and the question becomes which model gets it right. These lead the hardest independent exams.

Updated Oct 10, 2026 · 3 models qualify · kept by WrenFull leaderboard
  1. 1

    GPT-6 Astra · OpenAI

    The reasoning heavyweight: leads the hardest exams and the cipher-cracking party tricks, and charges like it.

    Hard reasoningResearch-grade analysisWhen cost is not the constraintScore 86Index 53$10 in · $50 out per 1M1M context

    Caveat: Long-context pricing doubles above 272K input tokens.

  2. 2

    GPT-6.1 Sol · OpenAI

    Near-Astra intelligence at a fifth of the price, which is OpenAI's own line and, for once, the index agrees.

    Cost-controlled reasoningScore 82Index 52$2 in · $10 out per 1M1M context
  3. 3

    Claude Fable 5.1 · Anthropic

    The specialist: Anthropic's own docs say to reach for it when Opus 5.5 at high effort still falls short, and the price says the same.

    Problems Opus fails onDemanding reasoningScore 80Index 53$10 in · $50 out per 1M1M context

    Caveat: Ten dollars per million input is the highest in this table alongside Astra.

Head to head

Questions people ask

What is the best AI model for hard reasoning right now?

GPT-6 Astra (OpenAI) leads this list as of October 2026: The reasoning heavyweight: leads the hardest exams and the cipher-cracking party tricks, and charges like it. It costs $10 per million input tokens and $50 per million output tokens on the vendor's list price.

What is the runner-up for hard reasoning?

GPT-6.1 Sol (OpenAI): Near-Astra intelligence at a fifth of the price, which is OpenAI's own line and, for once, the index agrees.

How is this list ranked?

By the Models at Work leaderboard score: Score is 0 to 100: 50% independent evals normalised within this table, 20% price-performance, 15% practitioner sentiment from Signals and community threads, 15% operational fit (context, speed, availability, open weights). Models within three points are a tie in practice. Vendor-published figures are labelled as such and never counted as independent.

Other jobs

Every figure links to its source on the model profile pages. Vendor figures are labelled as vendor figures and never counted as independent.