DeepSeek-V3.1 Launches Hybrid Reasoning in One Model

Aug 21, 2025 — DeepSeek announced V3.1, describing a hybrid inference structure that supports two operating modes in a single model and touting faster processing and stronger agent capability. The company also signaled upcoming API pricing adjustments effective Sep 6, 2025 according to Reuters.

Both public docs and the model card confirm that deepseek-chat now corresponds to V3.1’s non-thinking mode and deepseek-reasoner corresponds to its thinking mode, letting teams switch behavior without changing models.

DeepSeek says V3.1-Think reaches answers in less time than DeepSeek-R1-0528 and shows better tool usage and multi-step agent performance after post-training optimization. The official release notes also surface a simple UI toggle to switch modes.

Benchmarks reported by DeepSeek list SWE-bench Verified at 66.0, SWE-bench Multilingual at 54.5, and Terminal-bench at 31.3. Use these as directional signals and validate with your own repos and prompts before committing workloads.

For integration, the DeepSeek API is OpenAI-compatible, which simplifies client updates and orchestration for teams already using OpenAI SDKs or compatible tooling.

What to evaluate next with DeepSeek’s new model launch

Latency and throughput in Think vs Non-Think mode, tool-use reliability under your agent framework, citation behavior in code and long-context tasks, and policy controls for logging and retention. Track API pricing changes as they go live on Sep 6, 2025 to model unit economics by use case.