Claude Opus 5.5 vs DeepSeek V4.1 Flash 1017
As of Nov 3, 2026, Claude Opus 5.5 leads DeepSeek V4.1 Flash 1017 in 5 of 5 shared categories: General LLM, Science, Coding, Abstraction (ARC), and Legal.
Claude Opus 5.5
Yes. SOTA in General LLM (tied), Reasoning (tied), Coding (tied), Coding › Agentic (tied), Coding › Web dev, Long context (tied), and Factuality (tied).
DeepSeek V4.1 Flash 1017
Yes. Yes on Coding (best per dollar). Not the overall leader.
| Category | Claude Opus 5.5 | DeepSeek V4.1 Flash 1017 |
|---|---|---|
| General LLM | #1 · Co-SOTA · General LLM Margin 0 LMArena leaderboard dataset · Nov 3, 2026 | #60 · #60 in General LLM Margin 33.421750663129984 Vals AI · Nov 3, 2026 |
| Reasoning | #1 · Co-SOTA · Reasoning Margin 0 LMArena leaderboard dataset · Oct 28, 2026 | #— · Not enough data Margin — Epoch AI benchmarking hub · Oct 17, 2026 |
| Science | #2 · #2 in Science Margin — Vals AI · Oct 30, 2026 | #17 · #17 in Science Margin — Epoch AI benchmarking hub · Oct 17, 2026 |
| Coding | #1 · Co-SOTA · Coding Margin 0 Terminal-Bench Harbor Hub · Nov 3, 2026 | #8 · #8 in Coding Margin 23.919753086419746 Vals AI · Nov 3, 2026 |
| Coding › Agentic | #1 · Co-SOTA · Coding › Agentic Margin 0 Terminal-Bench Harbor Hub · Oct 23, 2026 | — |
| Coding › Web dev | #1 · SOTA · Coding › Web dev Margin 0 LMArena leaderboard dataset · Oct 28, 2026 | — |
| Long context | #1 · Co-SOTA · Long context Margin 0 LMArena leaderboard dataset · Oct 28, 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 28, 2026 | #— · Not enough data Margin — Epoch AI benchmarking hub · Oct 17, 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 · Oct 17, 2026 |
| Cybersecurity | #4 · #4 in Cybersecurity Margin 9.375 Vals AI · Oct 27, 2026 | — |
| Finance | #1 · #1 in Finance Margin — Vals AI · Oct 31, 2026 | — |
| Legal | #5 · #5 in Legal Margin — Vals AI · Nov 3, 2026 | #12 · #12 in Legal Margin — Vals AI · Nov 3, 2026 |
Which is better for coding?
As of Nov 3, 2026, Claude Opus 5.5 leads DeepSeek V4.1 Flash 1017 in Coding at #1 against #8. See the full coding ranking.
Pricing
Claude Opus 5.5: $8 per 1M blended tokens.
DeepSeek V4.1 Flash 1017: $0.52 per 1M blended tokens.
Claude Opus 5.5: closed weights.
DeepSeek V4.1 Flash 1017: open weights.
Benchmarks side by side
| Benchmark | Claude Opus 5.5 | DeepSeek V4.1 Flash 1017 |
|---|---|---|
| ARC-AGI | 98.5% | 94.5% |
| Code Migration | 81.0 | 67.5 |
| Excel Modeling Benchmark (EMB) | 75.8 | 69.2 |
| Finance Agent | 67.8 | 62.9 |
| GPQA Diamond | 90.6% | 93.2% |
| Legal Research Bench | 50.5 | 45.2 |
| SimpleQA Verified | 72.2% | 42.5% |
| Tax Agent Bench | 45.6 | 44.4 |
| Vals Index | 70.2 | 61.3 |
| Vibe Code Bench | 90.3 | 87.7 |
Latest validated result for each model. Benchmarks where only one model has a result are left out.
Verdict
As of Nov 3, 2026, Claude Opus 5.5 leads DeepSeek V4.1 Flash 1017 in 5 of 5 shared categories: General LLM, Science, Coding, Abstraction (ARC), and Legal.
General LLM: As of Nov 3, 2026, Claude Opus 5.5 leads DeepSeek V4.1 Flash 1017 in General LLM at #1 against #60.
Science: As of Nov 3, 2026, Claude Opus 5.5 leads DeepSeek V4.1 Flash 1017 in Science at #2 against #17.
Coding: As of Nov 3, 2026, Claude Opus 5.5 leads DeepSeek V4.1 Flash 1017 in Coding at #1 against #8.
Abstraction (ARC): As of Nov 3, 2026, Claude Opus 5.5 leads DeepSeek V4.1 Flash 1017 in Abstraction (ARC) at #1 against #8.
Legal: As of Nov 3, 2026, Claude Opus 5.5 leads DeepSeek V4.1 Flash 1017 in Legal at #5 against #12.
Claude Opus 5.5 · DeepSeek V4.1 Flash 1017
Claude Opus 5.5 or DeepSeek V4.1 Flash 1017?
As of Nov 3, 2026, Claude Opus 5.5 leads DeepSeek V4.1 Flash 1017 in 5 of 5 shared categories: General LLM, Science, Coding, Abstraction (ARC), and Legal.
Claude Opus 5.5 or DeepSeek V4.1 Flash 1017 for General LLM?
As of Nov 3, 2026, Claude Opus 5.5 leads DeepSeek V4.1 Flash 1017 in General LLM at #1 against #60.
Claude Opus 5.5 or DeepSeek V4.1 Flash 1017 for Science?
As of Nov 3, 2026, Claude Opus 5.5 leads DeepSeek V4.1 Flash 1017 in Science at #2 against #17.
Claude Opus 5.5 or DeepSeek V4.1 Flash 1017 for Coding?
As of Nov 3, 2026, Claude Opus 5.5 leads DeepSeek V4.1 Flash 1017 in Coding at #1 against #8.