Last updated: April 5, 2026 · Prompting & Usage · by Daniel Ashford
What is Chain-of-Thought (CoT)?
A prompting technique that asks the model to show its reasoning step by step.
Definition
Chain-of-Thought prompting instructs the model to break down its reasoning into explicit, sequential steps before arriving at an answer. This significantly improves accuracy on multi-step reasoning, math, logic, and complex analysis.
How It Works
CoT works because forcing the model to generate intermediate steps gives it more computation — each token builds on previous ones. Modern reasoning models like OpenAI o3 and Claude with extended thinking have CoT built into their architecture.
Example
Without CoT: "What is 17 x 23?" often wrong. With CoT: "Think step by step. 17 x 20 = 340, 17 x 3 = 51, 340 + 51 = 391." — more reliable.
Related Terms
See How Models Compare
Understanding chain-of-thought (cot) is important when choosing the right AI model. See how 12 models compare on our leaderboard.