# Claude Opus 4.5 vs DeepSeek V4 Flash

> DeepSeek V4 Flash is the stronger model overall, scoring 53.6 to 50.5 on the Noometry Index.

- Canonical page: https://noometry.com/compare/claude-opus-4-5-vs-deepseek-v4-flash
- Last updated: 2026-10-10
- Shared benchmarks: 37

## Summary

- They share 37 benchmarks with published results for both. Claude Opus 4.5 scores higher in 6 categories and DeepSeek V4 Flash in 2 categories; 8 gaps are clear of the uncertainty.
- The widest gap is in math, where DeepSeek V4 Flash leads 60.3 to 38.6.
- The biggest single-benchmark swing is NYT Connections (extended): 52.5% for Claude Opus 4.5 and 89.6% for DeepSeek V4 Flash.
- DeepSeek V4 Flash is cheaper at $0.15 / $0.60 per million input/output tokens, against $5 / $25 for Claude Opus 4.5.
- DeepSeek V4 Flash accepts more context: 1M tokens versus 200K.
- DeepSeek V4 Flash has downloadable open weights; the other is API-only.

## Snapshot

| | Claude Opus 4.5 | DeepSeek V4 Flash |
|---|---|---|
| Provider | Anthropic | DeepSeek |
| Noometry Index | 50.5 | 53.6 |
| Rank | 47 | 35 |
| Context | 200K | 1M |
| Input $/M | $5 | $0.15 |
| Output $/M | $25 | $0.60 |
| Weights | Proprietary | Open |

## Coding

- Claude Opus 4.5: 54.8 (#27)
- DeepSeek V4 Flash: 47.9 (#59)

| Benchmark | Claude Opus 4.5 | DeepSeek V4 Flash |
|---|---|---|
| LMArena WebDev | 1494 | 1582 |
| WeirdML | 63.7% | 63% |
| LMArena Coding | 1504 | 1457 |
| ALE-Bench | 1,025 | 1,306 |
| SWE-bench Verified | 76.7% | — |
| FrontierCode | — | 18.8% |
| SWE-bench Verified (bash only) | 76.8% | — |
| SWE-bench Multilingual | 70.7% | — |
| SciCode | — | 49.9% |
| GSO | 26.5% | — |
| AlgoTune | 1.77 | — |

## Agentic & Tool Use

- Claude Opus 4.5: 47.3 (#12)
- DeepSeek V4 Flash: —

| Benchmark | Claude Opus 4.5 | DeepSeek V4 Flash |
|---|---|---|
| Terminal-Bench | 63.1% | — |
| Berkeley Function Calling Leaderboard | 77.5% | — |
| GDPval | 45.5% | — |
| Remote Labor Index | 3.8% | — |
| τ²-bench Airline | 84% | — |
| τ²-bench Banking | 24.7% | — |
| τ²-bench Retail | 79.6% | — |
| τ²-bench Telecom | 92.3% | — |
| Cybench | 82% | — |
| DeepResearch Bench | 54.8% | — |
| OSWorld | 66.3% | — |
| BALROG | 43.5% | — |
| LMArena Search | 1180 | — |
| METR Time Horizons | 75% | — |
| Vending-Bench 2 | 4,967 | — |

## Reasoning

- Claude Opus 4.5: 42.6 (#51)
- DeepSeek V4 Flash: 53.7 (#30)

| Benchmark | Claude Opus 4.5 | DeepSeek V4 Flash |
|---|---|---|
| ARC-AGI-2 | 37.6% | 61.4% |
| SimpleBench | 62% | 61.1% |
| Kagi LLM Benchmark | 80.2% | 52.2% |
| NYT Connections (extended) | 52.5% | 89.6% |
| ARC-AGI-1 | 80% | 89% |
| Chess Puzzles | 12% | 33% |
| LMArena Hard Prompts | 1476 | 1444 |
| Mystery Game Puzzles | 22% | 34% |
| DTBench | 89.9% | 90.9% |
| LMCA | 44.5% | 41.7% |
| Epoch Capabilities Index | 150.09 | 154.49 |
| CritPt | — | 16.6% |
| EnigmaEval | 11.9% | — |
| EBR-Bench | 14.3% | — |
| ForecastBench | 60.7 | — |

## Math

- Claude Opus 4.5: 38.6 (#132)
- DeepSeek V4 Flash: 60.3 (#37)

| Benchmark | Claude Opus 4.5 | DeepSeek V4 Flash |
|---|---|---|
| FrontierMath (Tiers 1-3) | 34.4% | 57.5% |
| FrontierMath Tier 4 | 4.9% | 24.4% |
| OTIS Mock AIME 2024-2025 | 86.1% | 94.4% |
| ProofBench | 36% | 56% |
| LMArena Math | 1463 | 1427 |
| MathArena Final-Answer Competitions | — | 76.5% |
| FrontierMath (Feb 2025 set) | 20.7% | — |
| FrontierMath Tier 4 (v1) | 4.2% | — |

## Knowledge

- Claude Opus 4.5: 56.5 (#44)
- DeepSeek V4 Flash: 55.4 (#48)

| Benchmark | Claude Opus 4.5 | DeepSeek V4 Flash |
|---|---|---|
| GPQA Diamond | 86% | 91% |
| SimpleQA Verified | 45.7% | 33.6% |
| LMArena Expert | 1487 | 1441 |
| Humanity's Last Exam | 25.2% | — |
| Vectara Hallucination Rate | 10.9% | — |

## Multimodal

- Claude Opus 4.5: 31.4 (#107)
- DeepSeek V4 Flash: —

| Benchmark | Claude Opus 4.5 | DeepSeek V4 Flash |
|---|---|---|
| GeoBench | 75% | — |
| VPCT | 40% | — |
| Furniture Assembly | 28.3% | — |
| LMArena Document | 1462 | — |

## Multilingual

- Claude Opus 4.5: 54.3 (#47)
- DeepSeek V4 Flash: 53.0 (#72)

| Benchmark | Claude Opus 4.5 | DeepSeek V4 Flash |
|---|---|---|
| LMArena Non-English | 1438 | 1420 |
| LMArena Chinese | 1470 | 1468 |
| LMArena French | 1471 | 1439 |
| LMArena German | 1449 | 1418 |
| LMArena Japanese | 1416 | 1406 |
| LMArena Korean | 1424 | 1384 |
| LMArena Russian | 1447 | 1428 |
| LMArena Spanish | 1458 | 1436 |

## Instruction Following

- Claude Opus 4.5: 77.5 (#19)
- DeepSeek V4 Flash: 74.9 (#81)

| Benchmark | Claude Opus 4.5 | DeepSeek V4 Flash |
|---|---|---|
| LMArena Instruction Following | 1478 | 1421 |

## Long Context

- Claude Opus 4.5: 46.5 (#22)
- DeepSeek V4 Flash: 43.8 (#85)

| Benchmark | Claude Opus 4.5 | DeepSeek V4 Flash |
|---|---|---|
| LMArena Longer Query | 1480 | 1434 |
| CL-bench | 21.1% | — |

## Writing & Preference

- Claude Opus 4.5: 68.1 (#28)
- DeepSeek V4 Flash: 63.8 (#61)

| Benchmark | Claude Opus 4.5 | DeepSeek V4 Flash |
|---|---|---|
| LMArena Text | 1451 | 1432 |
| LMArena Creative Writing | 1445 | 1403 |
| EQ-Bench Creative Writing | 1687 | 1559 |
| LMArena Multi-Turn | 1466 | 1449 |

## FAQ

### Is Claude Opus 4.5 better than DeepSeek V4 Flash?

DeepSeek V4 Flash is the stronger model overall, scoring 53.6 to 50.5 on the Noometry Index.

### Which is cheaper, Claude Opus 4.5 or DeepSeek V4 Flash?

DeepSeek V4 Flash is cheaper. It lists at $0.15 per million input tokens and $0.60 per million output tokens; Claude Opus 4.5 lists at $5 and $25.

### Is Claude Opus 4.5 or DeepSeek V4 Flash better for coding?

Claude Opus 4.5 scores higher on coding benchmarks: 54.8 versus 47.9 in the Noometry coding category.

### Which has the bigger context window?

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

### How many benchmarks do Claude Opus 4.5 and DeepSeek V4 Flash share?

37 benchmarks have published results for both models. Claude Opus 4.5 has 69 scored results on Noometry and DeepSeek V4 Flash has 41.