DeepSeek iconDeepSeek: DeepSeek V3.1 Terminus

Model Type

Proprietary model icon

Proprietary Model

API access only

Recommended Use Cases

Text Generation

A stability-focused update to DeepSeek-V3.1, representing the final refinement of the V3.1 architecture (September 2025). Terminus addresses user-reported issues around language consistency and agent performance.

Per DeepSeek:

DeepSeek-V3.1-Terminus delivers more stable & reliable outputs across benchmarks compared to the previous version.

Role in V3.1 Series

Terminus is the "final" version of V3.1, focusing on polish and stability rather than new capabilities. It fixes issues with mixed Chinese-English text and optimizes Code Agent and Search Agent performance based on user feedback.

Key Features

  • Architecture: 685B MoE (671B parameters, 37B active)
  • Context Window: 128K tokens
  • Hybrid Modes: Supports both thinking and non-thinking modes
  • License: MIT

Improvements Over V3.1

  • Language Consistency: Reduced instances of mixed Chinese-English text and abnormal characters
  • Agent Capabilities: Further optimized Code Agent and Search Agent performance
  • Search Tool Updates: Updated template and tool-set for search agent

Links