Claude Opus 5.5 vs DeepSeek V4 Flash
As of Oct 14, 2026, Claude Opus 5.5 leads DeepSeek V4 Flash in 5 of 5 shared categories: General LLM, Reasoning, Coding › Web dev, Long context, and Factuality.
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 Flash
Yes. Yes on General LLM (best per dollar); Reasoning (best per dollar). Not the overall leader.
| Category | Claude Opus 5.5 | DeepSeek V4 Flash |
|---|---|---|
| General LLM | #2 · Near-SOTA · General LLM Margin 1.3605442176870781 LMArena leaderboard dataset · Oct 13, 2026 | #75 · #75 in General LLM Margin 51.02040816326531 LMArena leaderboard dataset · Oct 13, 2026 |
| Reasoning | #1 · Co-SOTA · Reasoning Margin 0 LMArena leaderboard dataset · Oct 13, 2026 | #72 · #72 in Reasoning Margin 50 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 | — |
| 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 | #30 · #30 in Coding › Web dev Margin 27.10280373831776 LMArena leaderboard dataset · Oct 13, 2026 |
| Long context | #1 · Co-SOTA · Long context Margin 0 LMArena leaderboard dataset · Oct 13, 2026 | #69 · #69 in Long context Margin 46.93877551020408 LMArena leaderboard dataset · Oct 13, 2026 |
| Vision | #4 · Near-SOTA · Vision Margin 13.15789473684211 Epoch AI benchmarking hub · Sep 22, 2026 | — |
| Factuality | #1 · Co-SOTA · Factuality Margin 0 LMArena leaderboard dataset · Oct 13, 2026 | #66 · #66 in Factuality Margin 50 LMArena leaderboard dataset · Oct 13, 2026 |
| Abstraction (ARC) | #1 · #1 in Abstraction (ARC) Margin — Epoch AI benchmarking hub · Sep 22, 2026 | — |
Claude Opus 5.5: $8.000000000000002 per 1M blended tokens.
DeepSeek V4 Flash: $0.11374999999999999 per 1M blended tokens.
Claude Opus 5.5: closed weights.
DeepSeek V4 Flash: open weights.
General LLM: As of Oct 14, 2026, Claude Opus 5.5 leads DeepSeek V4 Flash in General LLM at #2 against #75.
Reasoning: As of Oct 14, 2026, Claude Opus 5.5 leads DeepSeek V4 Flash in Reasoning at #1 against #72.
Coding › Web dev: As of Oct 14, 2026, Claude Opus 5.5 leads DeepSeek V4 Flash in Coding › Web dev at #1 against #30.
Long context: As of Oct 14, 2026, Claude Opus 5.5 leads DeepSeek V4 Flash in Long context at #1 against #69.
Factuality: As of Oct 14, 2026, Claude Opus 5.5 leads DeepSeek V4 Flash in Factuality at #1 against #66.
Claude Opus 5.5 · DeepSeek V4 Flash
Claude Opus 5.5 or DeepSeek V4 Flash?
As of Oct 14, 2026, Claude Opus 5.5 leads DeepSeek V4 Flash in 5 of 5 shared categories: General LLM, Reasoning, Coding › Web dev, Long context, and Factuality.
Claude Opus 5.5 or DeepSeek V4 Flash for General LLM?
As of Oct 14, 2026, Claude Opus 5.5 leads DeepSeek V4 Flash in General LLM at #2 against #75.
Claude Opus 5.5 or DeepSeek V4 Flash for Reasoning?
As of Oct 14, 2026, Claude Opus 5.5 leads DeepSeek V4 Flash in Reasoning at #1 against #72.
Claude Opus 5.5 or DeepSeek V4 Flash for Coding › Web dev?
As of Oct 14, 2026, Claude Opus 5.5 leads DeepSeek V4 Flash in Coding › Web dev at #1 against #30.