Large Language Models

DeepSeek R1 vs OpenAI o1 vs Claude (2026): Which AI Thinks Better?

The Best Reasoning Models of 2026 Compared

🕐 11 min read 👁 328 views 📅 Mar 17, 2026

🏆 Winner

DeepSeek R1

Open-source reasoning model matching o1

9.2 / 10

$0.55/M tokens

Full Review →

OpenAI o1

Extended chain-of-thought reasoning model

8.9 / 10

$15/M tokens

Full Review →

Claude 3.5 Sonnet

Best general-purpose LLM with strong reasoning

9.2 / 10

$3/M tokens

Full Review →

Head-to-Head Scores

Criterion	DeepSeek R1	OpenAI o1	Claude 3.5 Sonnet
Math & Science	9.5	9.5	8.8
Coding Benchmarks	9.2	9.2	9.3
Reasoning Quality	9.3	9.5	9.0
Speed	8.0	6.0	8.8
Cost per Token	9.5	6.0	8.5
Open Source	10.0	1.0	1.0

Pros & Cons

DeepSeek R1

+ Pros

− Cons

OpenAI o1

+ Pros

− Cons

Claude 3.5 Sonnet

+ Pros

− Cons

⚖ Our Verdict

DeepSeek R1 is the best value reasoning model — matches o1 on benchmarks at 20x lower cost. o1 wins on the very hardest problems. Claude 3.5 Sonnet wins for general use where reasoning and writing quality both matter.