# Claude Sonnet 4.6 vs DeepSeek V4.1 Flash

> Claude Sonnet 4.6 and DeepSeek V4.1 Flash score almost the same on the Noometry Index (50.1 vs 50.3), so choose on price, context window or the category you care about most.

- Canonical page: https://noometry.com/compare/claude-sonnet-4-6-vs-deepseek-v4-1-flash
- Last updated: 2026-10-10
- Shared benchmarks: 24

## Summary

- They share 24 benchmarks with published results for both. Claude Sonnet 4.6 scores higher in 5 categories and DeepSeek V4.1 Flash in 3 categories; 4 gaps are clear of the uncertainty.
- The widest gap is in knowledge, where Claude Sonnet 4.6 leads 51.6 to 41.6.
- The biggest single-benchmark swing is CritPt: 3.1% for Claude Sonnet 4.6 and 14.3% for DeepSeek V4.1 Flash.
- DeepSeek V4.1 Flash is cheaper at $0.15 / $0.60 per million input/output tokens, against $3 / $15 for Claude Sonnet 4.6.
- DeepSeek V4.1 Flash has downloadable open weights; the other is API-only.

## Snapshot

| | Claude Sonnet 4.6 | DeepSeek V4.1 Flash |
|---|---|---|
| Provider | Anthropic | DeepSeek |
| Noometry Index | 50.1 | 50.3 |
| Rank | 42 | 40 |
| Context | 1M | 1M |
| Input $/M | $3 | $0.15 |
| Output $/M | $15 | $0.60 |
| Weights | Proprietary | Open |

## Coding

- Claude Sonnet 4.6: 46.0 (#62)
- DeepSeek V4.1 Flash: 52.8 (#29)

| Benchmark | Claude Sonnet 4.6 | DeepSeek V4.1 Flash |
|---|---|---|
| LMArena WebDev | 1521 | 1620 |
| SciCode | 46.8% | 51.9% |
| LMArena Coding | 1504 | 1511 |
| ALE-Bench | 1,327 | 1,092 |
| SWE-bench Verified | 75.2% | — |
| DeepSWE | 29.9% | — |
| FrontierCode | 24.3% | — |
| WeirdML | 66.1% | — |

## Agentic & Tool Use

- Claude Sonnet 4.6: 39.1 (#26)
- DeepSeek V4.1 Flash: —

| Benchmark | Claude Sonnet 4.6 | DeepSeek V4.1 Flash |
|---|---|---|
| Terminal-Bench | 53.4% | — |
| APEX-Agents | 43% | — |
| OSWorld 2.0 | 9.3% | — |
| DeepResearch Bench | 54.9% | — |
| OSWorld | 72.1% | — |
| ExploitBench | 23.6% | — |
| GBAEval | 48.8% | — |
| GDP.pdf | 18% | — |
| LMArena Search | 1221 | — |
| Vending-Bench 2 | 7,204 | — |

## Reasoning

- Claude Sonnet 4.6: 46.1 (#40)
- DeepSeek V4.1 Flash: 46.2 (#39)

| Benchmark | Claude Sonnet 4.6 | DeepSeek V4.1 Flash |
|---|---|---|
| NYT Connections (extended) | 80.9% | 89.6% |
| CritPt | 3.1% | 14.3% |
| LMArena Hard Prompts | 1485 | 1485 |
| DTBench | 89.9% | 89.9% |
| LMCA | 46.5% | 47% |
| Epoch Capabilities Index | 152.25 | 155.01 |
| ARC-AGI-2 | 60.4% | — |
| ARC-AGI-1 | 86.5% | — |
| Chess Puzzles | 13% | — |
| Thematic Generalization | 76.3% | — |
| Mystery Game Puzzles | 16% | — |
| Surface Evolver Bench | — | 46.3% |
| ForecastBench | 62 | — |

## Math

- Claude Sonnet 4.6: 51.9 (#41)
- DeepSeek V4.1 Flash: 48.4 (#52)

| Benchmark | Claude Sonnet 4.6 | DeepSeek V4.1 Flash |
|---|---|---|
| ProofBench | 45% | 54% |
| LMArena Math | 1463 | 1493 |
| OTIS Mock AIME 2024-2025 | 85.8% | — |
| FrontierMath (Feb 2025 set) | 32.4% | — |
| FrontierMath Tier 4 (v1) | 8.3% | — |

## Knowledge

- Claude Sonnet 4.6: 51.6 (#60)
- DeepSeek V4.1 Flash: 41.6 (#97)

| Benchmark | Claude Sonnet 4.6 | DeepSeek V4.1 Flash |
|---|---|---|
| LMArena Expert | 1500 | 1505 |
| GPQA Diamond | 87.4% | — |
| SimpleQA Verified | 35.5% | — |
| Vectara Hallucination Rate | 10.6% | — |

## Multimodal

- Claude Sonnet 4.6: 38.0 (#61)
- DeepSeek V4.1 Flash: —

| Benchmark | Claude Sonnet 4.6 | DeepSeek V4.1 Flash |
|---|---|---|
| LMArena Vision | 1283 | — |
| Blueprint-Bench 2 | 6.7% | — |
| LMArena Document | 1482 | — |

## Multilingual

- Claude Sonnet 4.6: 54.6 (#39)
- DeepSeek V4.1 Flash: 55.5 (#29)

| Benchmark | Claude Sonnet 4.6 | DeepSeek V4.1 Flash |
|---|---|---|
| LMArena Non-English | 1440 | 1452 |
| LMArena Chinese | 1491 | 1506 |
| LMArena French | 1465 | 1448 |
| LMArena Russian | 1440 | 1473 |
| LMArena Spanish | 1465 | 1499 |
| LMArena German | 1428 | — |
| LMArena Japanese | 1419 | — |
| LMArena Korean | 1411 | — |

## Instruction Following

- Claude Sonnet 4.6: 77.6 (#23)
- DeepSeek V4.1 Flash: 77.6 (#24)

| Benchmark | Claude Sonnet 4.6 | DeepSeek V4.1 Flash |
|---|---|---|
| LMArena Instruction Following | 1476 | 1475 |

## Long Context

- Claude Sonnet 4.6: 45.3 (#40)
- DeepSeek V4.1 Flash: 45.2 (#46)

| Benchmark | Claude Sonnet 4.6 | DeepSeek V4.1 Flash |
|---|---|---|
| LMArena Longer Query | 1479 | 1476 |

## Writing & Preference

- Claude Sonnet 4.6: 70.4 (#22)
- DeepSeek V4.1 Flash: 65.8 (#43)

| Benchmark | Claude Sonnet 4.6 | DeepSeek V4.1 Flash |
|---|---|---|
| LMArena Text | 1458 | 1465 |
| LMArena Creative Writing | 1435 | 1436 |
| EQ-Bench Creative Writing | 1810 | 1540 |
| LMArena Multi-Turn | 1464 | 1460 |
| EQ-Bench 4 | 1207 | — |

## FAQ

### Is Claude Sonnet 4.6 better than DeepSeek V4.1 Flash?

Claude Sonnet 4.6 and DeepSeek V4.1 Flash score almost the same on the Noometry Index (50.1 vs 50.3), so choose on price, context window or the category you care about most.

### Which is cheaper, Claude Sonnet 4.6 or DeepSeek V4.1 Flash?

DeepSeek V4.1 Flash is cheaper. It lists at $0.15 per million input tokens and $0.60 per million output tokens; Claude Sonnet 4.6 lists at $3 and $15.

### Is Claude Sonnet 4.6 or DeepSeek V4.1 Flash better for coding?

DeepSeek V4.1 Flash scores higher on coding benchmarks: 52.8 versus 46.0 in the Noometry coding category.

### Which has the bigger context window?

Both accept 1M tokens.

### How many benchmarks do Claude Sonnet 4.6 and DeepSeek V4.1 Flash share?

24 benchmarks have published results for both models. Claude Sonnet 4.6 has 57 scored results on Noometry and DeepSeek V4.1 Flash has 25.