# Claude Opus 4.5 vs Gemini 3.8 Flash

> Gemini 3.8 Flash is the stronger model overall, scoring 61.8 to 50.5 on the Noometry Index.

- Canonical page: https://noometry.com/compare/claude-opus-4-5-vs-gemini-3-8-flash
- Last updated: 2026-10-10
- Shared benchmarks: 39

## Summary

- They share 39 benchmarks with published results for both. Claude Opus 4.5 scores higher in 2 categories and Gemini 3.8 Flash in 8 categories; 8 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where Gemini 3.8 Flash leads 76.9 to 42.6.
- The biggest single-benchmark swing is ARC-AGI-2: 37.6% for Claude Opus 4.5 and 89.2% for Gemini 3.8 Flash.
- Gemini 3.8 Flash is cheaper at $0.75 / $3.75 per million input/output tokens, against $5 / $25 for Claude Opus 4.5.
- Gemini 3.8 Flash accepts more context: 1.05M tokens versus 200K.

## Snapshot

| | Claude Opus 4.5 | Gemini 3.8 Flash |
|---|---|---|
| Provider | Anthropic | Google |
| Noometry Index | 50.5 | 61.8 |
| Rank | 47 | 11 |
| Context | 200K | 1.05M |
| Input $/M | $5 | $0.75 |
| Output $/M | $25 | $3.75 |
| Weights | Proprietary | Proprietary |

## Coding

- Claude Opus 4.5: 54.8 (#27)
- Gemini 3.8 Flash: 59.2 (#15)

| Benchmark | Claude Opus 4.5 | Gemini 3.8 Flash |
|---|---|---|
| LMArena WebDev | 1494 | 1584 |
| WeirdML | 63.7% | 84.8% |
| LMArena Coding | 1504 | 1510 |
| ALE-Bench | 1,025 | 1,270 |
| SWE-bench Verified | 76.7% | — |
| DeepSWE | — | 73.8% |
| FrontierCode | — | 41.2% |
| SWE-bench Verified (bash only) | 76.8% | — |
| CursorBench | — | 39.6% |
| SWE-bench Multilingual | 70.7% | — |
| FrontierSWE | — | 19.6% |
| SciCode | — | 56.6% |
| GSO | 26.5% | — |
| AlgoTune | 1.77 | — |

## Agentic & Tool Use

- Claude Opus 4.5: 47.3 (#12)
- Gemini 3.8 Flash: 41.8 (#21)

| Benchmark | Claude Opus 4.5 | Gemini 3.8 Flash |
|---|---|---|
| Remote Labor Index | 3.8% | 5.8% |
| Vending-Bench 2 | 4,967 | 5,094 |
| Terminal-Bench | 63.1% | — |
| APEX-Agents | — | 64.3% |
| Berkeley Function Calling Leaderboard | 77.5% | — |
| GDPval | 45.5% | — |
| 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% | — |
| GDP.pdf | — | 23.4% |
| LMArena Search | 1180 | — |
| METR Time Horizons | 75% | — |

## Reasoning

- Claude Opus 4.5: 42.6 (#51)
- Gemini 3.8 Flash: 76.9 (#5)

| Benchmark | Claude Opus 4.5 | Gemini 3.8 Flash |
|---|---|---|
| ARC-AGI-2 | 37.6% | 89.2% |
| NYT Connections (extended) | 52.5% | 97.4% |
| ARC-AGI-1 | 80% | 98.5% |
| Chess Puzzles | 12% | 61% |
| LMArena Hard Prompts | 1476 | 1508 |
| Mystery Game Puzzles | 22% | 47% |
| DTBench | 89.9% | 95.7% |
| LMCA | 44.5% | 52.9% |
| Epoch Capabilities Index | 150.09 | 156.71 |
| SimpleBench | 62% | — |
| Kagi LLM Benchmark | 80.2% | — |
| CritPt | — | 18.3% |
| EnigmaEval | 11.9% | — |
| EBR-Bench | 14.3% | — |
| Surface Evolver Bench | — | 76.9% |
| ForecastBench | 60.7 | — |

## Math

- Claude Opus 4.5: 38.6 (#132)
- Gemini 3.8 Flash: 65.3 (#28)

| Benchmark | Claude Opus 4.5 | Gemini 3.8 Flash |
|---|---|---|
| FrontierMath (Tiers 1-3) | 34.4% | 68.4% |
| FrontierMath Tier 4 | 4.9% | 22% |
| OTIS Mock AIME 2024-2025 | 86.1% | 98.9% |
| ProofBench | 36% | 48% |
| LMArena Math | 1463 | 1528 |
| FrontierMath (Feb 2025 set) | 20.7% | — |
| FrontierMath Tier 4 (v1) | 4.2% | — |

## Knowledge

- Claude Opus 4.5: 56.5 (#44)
- Gemini 3.8 Flash: 74.8 (#2)

| Benchmark | Claude Opus 4.5 | Gemini 3.8 Flash |
|---|---|---|
| GPQA Diamond | 86% | 95.4% |
| Humanity's Last Exam | 25.2% | 44.5% |
| SimpleQA Verified | 45.7% | 69.7% |
| LMArena Expert | 1487 | 1524 |
| Vectara Hallucination Rate | 10.9% | — |

## Multimodal

- Claude Opus 4.5: 31.4 (#107)
- Gemini 3.8 Flash: 40.7 (#45)

| Benchmark | Claude Opus 4.5 | Gemini 3.8 Flash |
|---|---|---|
| Furniture Assembly | 28.3% | 31.7% |
| LMArena Vision | — | 1314 |
| GeoBench | 75% | — |
| VPCT | 40% | — |
| Blueprint-Bench 2 | — | 38.6% |
| LMArena Document | 1462 | — |

## Multilingual

- Claude Opus 4.5: 54.3 (#47)
- Gemini 3.8 Flash: 58.0 (#5)

| Benchmark | Claude Opus 4.5 | Gemini 3.8 Flash |
|---|---|---|
| LMArena Non-English | 1438 | 1491 |
| LMArena Chinese | 1470 | 1554 |
| LMArena French | 1471 | 1498 |
| LMArena German | 1449 | 1493 |
| LMArena Japanese | 1416 | 1502 |
| LMArena Korean | 1424 | 1459 |
| LMArena Russian | 1447 | 1515 |
| LMArena Spanish | 1458 | 1485 |

## Instruction Following

- Claude Opus 4.5: 77.5 (#19)
- Gemini 3.8 Flash: 78.0 (#13)

| Benchmark | Claude Opus 4.5 | Gemini 3.8 Flash |
|---|---|---|
| LMArena Instruction Following | 1478 | 1490 |

## Long Context

- Claude Opus 4.5: 46.5 (#22)
- Gemini 3.8 Flash: 46.3 (#24)

| Benchmark | Claude Opus 4.5 | Gemini 3.8 Flash |
|---|---|---|
| LMArena Longer Query | 1480 | 1508 |
| CL-bench | 21.1% | — |

## Writing & Preference

- Claude Opus 4.5: 68.1 (#28)
- Gemini 3.8 Flash: 72.2 (#15)

| Benchmark | Claude Opus 4.5 | Gemini 3.8 Flash |
|---|---|---|
| LMArena Text | 1451 | 1499 |
| LMArena Creative Writing | 1445 | 1492 |
| EQ-Bench Creative Writing | 1687 | 1748 |
| LMArena Multi-Turn | 1466 | 1501 |

## FAQ

### Is Claude Opus 4.5 better than Gemini 3.8 Flash?

Gemini 3.8 Flash is the stronger model overall, scoring 61.8 to 50.5 on the Noometry Index.

### Which is cheaper, Claude Opus 4.5 or Gemini 3.8 Flash?

Gemini 3.8 Flash is cheaper. It lists at $0.75 per million input tokens and $3.75 per million output tokens; Claude Opus 4.5 lists at $5 and $25.

### Is Claude Opus 4.5 or Gemini 3.8 Flash better for coding?

Gemini 3.8 Flash scores higher on coding benchmarks: 59.2 versus 54.8 in the Noometry coding category.

### Which has the bigger context window?

Gemini 3.8 Flash does, with 1.05M tokens against 200K.

### How many benchmarks do Claude Opus 4.5 and Gemini 3.8 Flash share?

39 benchmarks have published results for both models. Claude Opus 4.5 has 69 scored results on Noometry and Gemini 3.8 Flash has 50.