Best LLMs for Reasoning in 2026

The pioneer of reasoning-focused LLMs, using extended chain-of-thought to solve problems that stump other models. Excels at multi-step logical deduction.

Best for: The most complex reasoning challenges

Extended thinking mode provides transparent, thorough reasoning with Anthropic's focus on accuracy and honesty. Excellent at nuanced judgment calls.

Best for: Nuanced reasoning requiring careful judgment

Open-source reasoning model with visible chain-of-thought. Achieves near-o1 performance while being free to inspect and modify.

Best for: Open-source reasoning with full transparency

Integrated reasoning capabilities that combine chain-of-thought with broad knowledge. Strong at both analytical and creative reasoning.

Best for: General reasoning across diverse domains

Deep thinking mode with strong performance on reasoning benchmarks. Particularly good at connecting information across very long contexts.

Best for: Reasoning over large volumes of information

Adjustable reasoning effort (low/medium/high) lets you control the depth of thinking. Cost-efficient for everyday reasoning tasks.

Best for: Everyday reasoning where full o1 power isn't needed