# Claude Opus 5.5 vs DeepSeek V3.1 Terminus

As of Oct 15, 2026, Claude Opus 5.5 leads DeepSeek V3.1 Terminus in 3 of 3 shared categories: General LLM, Reasoning, and Long context.

Claude Opus 5.5: $8.000000000000002 per 1M blended tokens.

DeepSeek V3.1 Terminus: $0.4525 per 1M blended tokens.

Claude Opus 5.5: closed weights.

DeepSeek V3.1 Terminus: open weights.

- Which to pick, General LLM: As of Oct 15, 2026, Claude Opus 5.5 leads DeepSeek V3.1 Terminus in General LLM at #2 against #128.
- Which to pick, Reasoning: As of Oct 15, 2026, Claude Opus 5.5 leads DeepSeek V3.1 Terminus in Reasoning at #1 against #142.
- Which to pick, Long context: As of Oct 15, 2026, Claude Opus 5.5 leads DeepSeek V3.1 Terminus in Long context at #1 against #133.

As of Oct 15, 2026, Claude Opus 5.5 is tied for state of the art in Reasoning (since Oct 2, 2026; sources LMArena Text (style-controlled, hard prompts); methodology v1.0).

As of Oct 15, 2026, DeepSeek V3.1 Terminus is ranked #128 in General LLM (since Oct 15, 2026; sources LMArena Text (style-controlled, overall); methodology v1.0).