Activate Thinking Mode for High-Compute Reasoning Tasks
Switch to DeepThink or Reasoner mode for complex math and logic tasks.
Use the 'deepseek-reasoner' or 'DeepThink' mode when dealing with high-difficulty math, international coding benchmarks, or complex research tasks.
The Scenario
You are building a complex visual demo or solving a difficult math-based coding problem that has stumped standard AI models.
Before & after
Users often try to solve complex logic or math problems using standard chat models, which may hallucinate or fail on edge cases, requiring 20–30 minutes of manual checking.
Select "deepseek-reasoner" (or V4-Pro/Flash versions) to engage the model's high-compute reasoning. This identifies the logic required and solves the problem in 2–3 minutes.
The Prompt
[PASTE_COMPLEX_PROBLEM_OR_CODE_SNIPPET] Please solve this using your 'Reasoning' or 'DeepThink' mode. Show your step-by-step chain of thought before providing the final answer.
DeepSeek models are branched into 'chat' (optimized for speed/conversation) and 'reasoner' (optimized for chain-of-thought and complex logic). The reasoner mode is specifically designed for international-level coding competitions and math benchmarks.
Source
Change Log | DeepSeek API Docs"deepseek-reasoner corresponds to DeepSeek-V3.2's thinking mode... matched GPT-5 in reasoning."