Claude Opus 5.5 vs DeepSeek V4.1 Flash
As of Oct 14, 2026, Claude Opus 5.5 leads DeepSeek V4.1 Flash in 8 of 8 shared categories: General LLM, Reasoning, Science, Coding › Web dev, Long context, Vision, Factuality, and Abstraction (ARC).
Claude Opus 5.5
Yes. SOTA in co-SOTA in Reasoning, co-SOTA in Coding, co-SOTA in Coding › Agentic, Coding › Web dev, co-SOTA in Long context and co-SOTA in Factuality.
DeepSeek V4.1 Flash
Yes. Yes on General LLM (best per dollar); Factuality (best per dollar). Not the overall leader.
| Category | Claude Opus 5.5 | DeepSeek V4.1 Flash |
|---|---|---|
| General LLM | #2 · Near-SOTA · General LLM Margin 1.3605442176870781 LMArena leaderboard dataset · Oct 13, 2026 | #29 · #29 in General LLM Margin 19.72789115646259 LMArena leaderboard dataset · Oct 13, 2026 |
| Reasoning | #1 · Co-SOTA · Reasoning Margin 0 LMArena leaderboard dataset · Oct 13, 2026 | #27 · #27 in Reasoning Margin 19.178082191780817 LMArena leaderboard dataset · Oct 13, 2026 |
| Math | #— · Not enough data Margin — LMArena leaderboard dataset · Oct 13, 2026 | #— · Not enough data Margin — LMArena leaderboard dataset · Oct 13, 2026 |
| Science | #31 · #31 in Science Margin — Epoch AI benchmarking hub · Sep 22, 2026 | #36 · #36 in Science Margin — Epoch AI benchmarking hub · Sep 9, 2026 |
| Coding | #1 · Co-SOTA · Coding Margin 0 Terminal-Bench Harbor Hub · Oct 6, 2026 | #— · Not enough data Margin — LMArena leaderboard dataset · Oct 13, 2026 |
| Coding › Agentic | #1 · Co-SOTA · Coding › Agentic Margin 0 Terminal-Bench Harbor Hub · Oct 6, 2026 | — |
| Coding › Web dev | #1 · SOTA · Coding › Web dev Margin 0 LMArena leaderboard dataset · Oct 13, 2026 | #19 · #19 in Coding › Web dev Margin 16.822429906542055 LMArena leaderboard dataset · Oct 13, 2026 |
| Long context | #1 · Co-SOTA · Long context Margin 0 LMArena leaderboard dataset · Oct 13, 2026 | #32 · #32 in Long context Margin 21.768707482993193 LMArena leaderboard dataset · Oct 13, 2026 |
| Vision | #4 · Near-SOTA · Vision Margin 13.15789473684211 Epoch AI benchmarking hub · Sep 22, 2026 | #21 · #21 in Vision Margin 57.89473684210526 Epoch AI benchmarking hub · Sep 9, 2026 |
| Factuality | #1 · Co-SOTA · Factuality Margin 0 LMArena leaderboard dataset · Oct 13, 2026 | #22 · #22 in Factuality Margin 17.164179104477626 LMArena leaderboard dataset · Oct 13, 2026 |
| Abstraction (ARC) | #1 · #1 in Abstraction (ARC) Margin — Epoch AI benchmarking hub · Sep 22, 2026 | #8 · #8 in Abstraction (ARC) Margin — Epoch AI benchmarking hub · Sep 9, 2026 |
Claude Opus 5.5: $8.000000000000002 per 1M blended tokens.
DeepSeek V4.1 Flash: $0.23787 per 1M blended tokens.
Claude Opus 5.5: closed weights.
DeepSeek V4.1 Flash: open weights.
General LLM: As of Oct 14, 2026, Claude Opus 5.5 leads DeepSeek V4.1 Flash in General LLM at #2 against #29.
Reasoning: As of Oct 14, 2026, Claude Opus 5.5 leads DeepSeek V4.1 Flash in Reasoning at #1 against #27.
Science: As of Oct 14, 2026, Claude Opus 5.5 leads DeepSeek V4.1 Flash in Science at #31 against #36.
Coding › Web dev: As of Oct 14, 2026, Claude Opus 5.5 leads DeepSeek V4.1 Flash in Coding › Web dev at #1 against #19.
Long context: As of Oct 14, 2026, Claude Opus 5.5 leads DeepSeek V4.1 Flash in Long context at #1 against #32.
Vision: As of Oct 14, 2026, Claude Opus 5.5 leads DeepSeek V4.1 Flash in Vision at #4 against #21.
Factuality: As of Oct 14, 2026, Claude Opus 5.5 leads DeepSeek V4.1 Flash in Factuality at #1 against #22.
Abstraction (ARC): As of Oct 14, 2026, Claude Opus 5.5 leads DeepSeek V4.1 Flash in Abstraction (ARC) at #1 against #8.
Claude Opus 5.5 · DeepSeek V4.1 Flash
Claude Opus 5.5 or DeepSeek V4.1 Flash?
As of Oct 14, 2026, Claude Opus 5.5 leads DeepSeek V4.1 Flash in 8 of 8 shared categories: General LLM, Reasoning, Science, Coding › Web dev, Long context, Vision, Factuality, and Abstraction (ARC).
Claude Opus 5.5 or DeepSeek V4.1 Flash for General LLM?
As of Oct 14, 2026, Claude Opus 5.5 leads DeepSeek V4.1 Flash in General LLM at #2 against #29.
Claude Opus 5.5 or DeepSeek V4.1 Flash for Reasoning?
As of Oct 14, 2026, Claude Opus 5.5 leads DeepSeek V4.1 Flash in Reasoning at #1 against #27.
Claude Opus 5.5 or DeepSeek V4.1 Flash for Science?
As of Oct 14, 2026, Claude Opus 5.5 leads DeepSeek V4.1 Flash in Science at #31 against #36.