# Claude Opus 4.1 vs DeepSeek V4.1 Flash

> DeepSeek V4.1 Flash is the stronger model overall, scoring 50.3 to 40.8 on the Noometry Index.

- Canonical page: https://noometry.com/compare/claude-opus-4-1-vs-deepseek-v4-1-flash
- Last updated: 2026-10-10
- Shared benchmarks: 19

## Summary

- They share 19 benchmarks with published results for both. Claude Opus 4.1 scores higher in 1 category and DeepSeek V4.1 Flash in 7 categories; 6 gaps are clear of the uncertainty.
- The widest gap is in math, where DeepSeek V4.1 Flash leads 48.4 to 22.0.
- The biggest single-benchmark swing is LMCA: 37.1% for Claude Opus 4.1 and 47% for DeepSeek V4.1 Flash.
- DeepSeek V4.1 Flash is cheaper at $0.15 / $0.60 per million input/output tokens, against $15 / $75 for Claude Opus 4.1.
- DeepSeek V4.1 Flash accepts more context: 1M tokens versus 200K.
- DeepSeek V4.1 Flash has downloadable open weights; the other is API-only.

## Snapshot

| | Claude Opus 4.1 | DeepSeek V4.1 Flash |
|---|---|---|
| Provider | Anthropic | DeepSeek |
| Noometry Index | 40.8 | 50.3 |
| Rank | 136 | 40 |
| Context | 200K | 1M |
| Input $/M | $15 | $0.15 |
| Output $/M | $75 | $0.60 |
| Weights | Proprietary | Open |

## Coding

- Claude Opus 4.1: 44.3 (#69)
- DeepSeek V4.1 Flash: 52.8 (#29)

| Benchmark | Claude Opus 4.1 | DeepSeek V4.1 Flash |
|---|---|---|
| LMArena WebDev | 1390 | 1620 |
| LMArena Coding | 1479 | 1511 |
| ALE-Bench | 674.77 | 1,092 |
| SWE-bench Verified | 73.3% | — |
| SciCode | — | 51.9% |
| WeirdML | 45.9% | — |
| AlgoTune | 1.34 | — |

## Agentic & Tool Use

- Claude Opus 4.1: 34.8 (#38)
- DeepSeek V4.1 Flash: —

| Benchmark | Claude Opus 4.1 | DeepSeek V4.1 Flash |
|---|---|---|
| Terminal-Bench | 38% | — |
| GDPval | 43.6% | — |
| Cybench | 42% | — |
| DeepResearch Bench | 48.3% | — |
| LMArena Search | 1148 | — |
| METR Time Horizons | 66.8% | — |

## Reasoning

- Claude Opus 4.1: 31.6 (#70)
- DeepSeek V4.1 Flash: 46.2 (#39)

| Benchmark | Claude Opus 4.1 | DeepSeek V4.1 Flash |
|---|---|---|
| LMArena Hard Prompts | 1443 | 1485 |
| DTBench | 80% | 89.9% |
| LMCA | 37.1% | 47% |
| Epoch Capabilities Index | 144.11 | 155.01 |
| SimpleBench | 60% | — |
| NYT Connections (extended) | — | 89.6% |
| CritPt | — | 14.3% |
| Chess Puzzles | 7% | — |
| EnigmaEval | 7.2% | — |
| EBR-Bench | 7.9% | — |
| Mystery Game Puzzles | 21% | — |
| Surface Evolver Bench | — | 46.3% |
| ForecastBench | 62 | — |

## Math

- Claude Opus 4.1: 22.0 (#267)
- DeepSeek V4.1 Flash: 48.4 (#52)

| Benchmark | Claude Opus 4.1 | DeepSeek V4.1 Flash |
|---|---|---|
| LMArena Math | 1430 | 1493 |
| FrontierMath (Tiers 1-3) | 12.6% | — |
| FrontierMath Tier 4 | 2.4% | — |
| OTIS Mock AIME 2024-2025 | 68.9% | — |
| ProofBench | — | 54% |
| FrontierMath (Feb 2025 set) | 7.2% | — |
| FrontierMath Tier 4 (v1) | 4.2% | — |

## Knowledge

- Claude Opus 4.1: 41.9 (#93)
- DeepSeek V4.1 Flash: 41.6 (#97)

| Benchmark | Claude Opus 4.1 | DeepSeek V4.1 Flash |
|---|---|---|
| LMArena Expert | 1439 | 1505 |
| GPQA Diamond | 77.3% | — |
| Humanity's Last Exam | 11.5% | — |
| Confabulations | 17.1% | — |
| Vectara Hallucination Rate | 11.8% | — |

## Multimodal

- Claude Opus 4.1: 26.2 (#114)
- DeepSeek V4.1 Flash: —

| Benchmark | Claude Opus 4.1 | DeepSeek V4.1 Flash |
|---|---|---|
| VPCT | 35% | — |

## Multilingual

- Claude Opus 4.1: 52.1 (#90)
- DeepSeek V4.1 Flash: 55.5 (#29)

| Benchmark | Claude Opus 4.1 | DeepSeek V4.1 Flash |
|---|---|---|
| LMArena Non-English | 1405 | 1452 |
| LMArena Chinese | 1427 | 1506 |
| LMArena French | 1432 | 1448 |
| LMArena Russian | 1421 | 1473 |
| LMArena Spanish | 1448 | 1499 |
| LMArena German | 1412 | — |
| LMArena Japanese | 1378 | — |
| LMArena Korean | 1381 | — |

## Instruction Following

- Claude Opus 4.1: 75.8 (#53)
- DeepSeek V4.1 Flash: 77.6 (#24)

| Benchmark | Claude Opus 4.1 | DeepSeek V4.1 Flash |
|---|---|---|
| LMArena Instruction Following | 1436 | 1475 |

## Long Context

- Claude Opus 4.1: 44.5 (#60)
- DeepSeek V4.1 Flash: 45.2 (#46)

| Benchmark | Claude Opus 4.1 | DeepSeek V4.1 Flash |
|---|---|---|
| LMArena Longer Query | 1455 | 1476 |

## Writing & Preference

- Claude Opus 4.1: 62.6 (#70)
- DeepSeek V4.1 Flash: 65.8 (#43)

| Benchmark | Claude Opus 4.1 | DeepSeek V4.1 Flash |
|---|---|---|
| LMArena Text | 1419 | 1465 |
| LMArena Creative Writing | 1412 | 1436 |
| LMArena Multi-Turn | 1444 | 1460 |
| Short-Story Creative Writing | 84.7% | — |
| EQ-Bench Creative Writing | — | 1540 |

## FAQ

### Is Claude Opus 4.1 better than DeepSeek V4.1 Flash?

DeepSeek V4.1 Flash is the stronger model overall, scoring 50.3 to 40.8 on the Noometry Index.

### Which is cheaper, Claude Opus 4.1 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 Opus 4.1 lists at $15 and $75.

### Is Claude Opus 4.1 or DeepSeek V4.1 Flash better for coding?

DeepSeek V4.1 Flash scores higher on coding benchmarks: 52.8 versus 44.3 in the Noometry coding category.

### Which has the bigger context window?

DeepSeek V4.1 Flash does, with 1M tokens against 200K.

### How many benchmarks do Claude Opus 4.1 and DeepSeek V4.1 Flash share?

19 benchmarks have published results for both models. Claude Opus 4.1 has 48 scored results on Noometry and DeepSeek V4.1 Flash has 25.