# Claude Sonnet 5.5 vs DeepSeek V4.1 Flash 1017

As of Nov 3, 2026, Claude Sonnet 5.5 leads DeepSeek V4.1 Flash 1017 in 5 of 5 shared categories: General LLM, Science, Coding, Abstraction (ARC), and Legal.

## Which is better for coding?

As of Nov 3, 2026, Claude Sonnet 5.5 leads DeepSeek V4.1 Flash 1017 in Coding at #1 against #8.

## Pricing

Claude Sonnet 5.5: $4 per 1M blended tokens.

DeepSeek V4.1 Flash 1017: $0.52 per 1M blended tokens.

Claude Sonnet 5.5: closed weights.

DeepSeek V4.1 Flash 1017: open weights.

## Benchmarks side by side

| Benchmark | Claude Sonnet 5.5 | DeepSeek V4.1 Flash 1017 |
| --- | ---: | ---: |
| ARC-AGI | 96.5% | 94.5% |
| Code Migration | 86.9 | 67.5 |
| Excel Modeling Benchmark (EMB) | 75.9 | 69.2 |
| Finance Agent | 67.3 | 62.9 |
| GPQA Diamond | 95.6% | 93.2% |
| Legal Research Bench | 48.1 | 45.2 |
| SimpleQA Verified | 46.5% | 42.5% |
| Tax Agent Bench | 42.0 | 44.4 |
| Vals Index | 70.9 | 61.3 |
| Vibe Code Bench | 92.4 | 87.7 |

## Verdict

As of Nov 3, 2026, Claude Sonnet 5.5 leads DeepSeek V4.1 Flash 1017 in 5 of 5 shared categories: General LLM, Science, Coding, Abstraction (ARC), and Legal.

- Which to pick, General LLM: As of Nov 3, 2026, Claude Sonnet 5.5 leads DeepSeek V4.1 Flash 1017 in General LLM at #17 against #60.
- Which to pick, Science: As of Nov 3, 2026, Claude Sonnet 5.5 leads DeepSeek V4.1 Flash 1017 in Science at #3 against #17.
- Which to pick, Coding: As of Nov 3, 2026, Claude Sonnet 5.5 leads DeepSeek V4.1 Flash 1017 in Coding at #1 against #8.
- Which to pick, Abstraction (ARC): As of Nov 3, 2026, Claude Sonnet 5.5 leads DeepSeek V4.1 Flash 1017 in Abstraction (ARC) at #4 against #8.
- Which to pick, Legal: As of Nov 3, 2026, Claude Sonnet 5.5 leads DeepSeek V4.1 Flash 1017 in Legal at #8 against #12.

As of Nov 3, 2026, Claude Sonnet 5.5 is tied for state of the art in Coding (since Oct 6, 2026; sources Terminal-Bench 4.0 and Code Migration; methodology v1.0).

As of Nov 3, 2026, DeepSeek V4.1 Flash 1017 is state of the art on best per dollar in Coding (since Oct 20, 2026; sources Code Migration; methodology v1.0).

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