# Claude Opus 4.5 vs Gemini 3 Flash

> Side-by-side benchmark comparison for Claude Opus 4.5 and Gemini 3 Flash across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/claude-opus-4-5-vs-gemini-3-flash
- Last updated: September 23, 2026

- Shared sourced benchmarks: 5
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.6

## Quick Verdict

Pick Claude Opus 4.5 if you want the stronger benchmark profile. Gemini 3 Flash only makes more sense when its price, context window, or workload-specific category wins matter more than the overall score.

## Summary

- Claude Opus 4.5 leads overall 55.9 to 55.62.
- The clearest category separation is in multimodal & grounded, where the averages are 23.5 for Claude Opus 4.5 and 75.8 for Gemini 3 Flash.
- The biggest single benchmark swing is JobBench in Agentic, with scores of 32.3% and 11.4%.
- Gemini 3 Flash is the cheaper option on output tokens, which matters if you expect large responses or heavy interactive use.
- Gemini 3 Flash also has the larger context window at 1M.

## Model Snapshot

| Property | Claude Opus 4.5 | Gemini 3 Flash |
|----------|----------|----------|
| Creator | Anthropic | Google |
| Type | Proprietary | Proprietary |
| Reasoning | Non-Reasoning | Non-Reasoning |
| Context | 200K | 1M |
| Overall Score | 55.9 | 55.62 |
| Benchmarks Covered | 45 | 11 |
| Pricing (input/output) | $5.00 / $25.00 | $0.50 / $3.00 |

## Category Breakdown

### Agentic

- Winner: Directional only
- Claude Opus 4.5 public-lane score: 31.4 (Estimated · #64/105)
- Gemini 3 Flash public-lane score: 31.4 (Supported · #65/105)

| Benchmark | Claude Opus 4.5 | Gemini 3 Flash | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 2.0 | 59.3% | Coming soon | Coming soon |
| OSWorld-Verified | 66.3% | Coming soon | Coming soon |
| OSWorld | 66.3% | Coming soon | Coming soon |
| Claw-Eval | 59.6% | 49.2% | Claude Opus 4.5 |
| QwenClawBench | 52.3% | Coming soon | Coming soon |
| τ³-bench results | 70.2% | Coming soon | Coming soon |
| VITA-Bench | 23.3% | Coming soon | Coming soon |
| DeepPlanning | 26.4% | Coming soon | Coming soon |
| Toolathlon | 43.5% | Coming soon | Coming soon |
| MCP Atlas | 42.3% | Coming soon | Coming soon |
| MCP-Tasks | 71.8% | Coming soon | Coming soon |
| WideResearch | 76.4% | Coming soon | Coming soon |
| CyberGym | 50.6% | Coming soon | Coming soon |
| Gert Labs | 64.23% | 56.63% | Claude Opus 4.5 |
| JobBench | 32.3% | 11.4% | Claude Opus 4.5 |
| Terminal-Bench 2.1 (Vals) | Coming soon | 53.9% | Coming soon |

### Coding

- Winner: Directional only
- Claude Opus 4.5 public-lane score: 46.1 (Estimated · #48/135)
- Gemini 3 Flash public-lane score: 36.9 (Supported · #75/135)

| Benchmark | Claude Opus 4.5 | Gemini 3 Flash | Winner |
|-----------|-----------|-----------|--------|
| SWE-bench Verified | 80.9% | Coming soon | Coming soon |
| LiveCodeBench v6 | 84.8% | Coming soon | Coming soon |
| SWE-bench Pro | 57.1% | Coming soon | Coming soon |
| SWE Multilingual | 77.5% | Coming soon | Coming soon |
| NL2Repo | 43.2% | Coming soon | Coming soon |
| Vibe Code Bench | Coming soon | 20.20% | Coming soon |
| LiveCodeBench (Vals) | Coming soon | 85.6% | Coming soon |
| SWE-bench (Vals) | Coming soon | 75.0% | Coming soon |

### Reasoning

- Winner: Not comparable
- Claude Opus 4.5 public-lane score: 72.1 (Unranked · 4 rankable rows)
- Gemini 3 Flash public-lane score: 59 (Unranked · 2 rankable rows)

| Benchmark | Claude Opus 4.5 | Gemini 3 Flash | Winner |
|-----------|-----------|-----------|--------|
| LongBench v2 | 64.4% | Coming soon | Coming soon |
| AI-Needle | 74% | Coming soon | Coming soon |

### Multimodal & Grounded

- Winner: Not comparable
- Claude Opus 4.5 public-lane score: 23.5 (#48/50)
- Gemini 3 Flash public-lane score: 75.8 (Unranked · 1 rankable row)

| Benchmark | Claude Opus 4.5 | Gemini 3 Flash | Winner |
|-----------|-----------|-----------|--------|
| MMMU-Pro | 70.6% | Coming soon | Coming soon |
| MathVision | 74.3% | Coming soon | Coming soon |
| CharXiv | 68.5% | Coming soon | Coming soon |
| VideoMMMU | 84.4% | Coming soon | Coming soon |
| ScreenSpot Pro | 45.7% | Coming soon | Coming soon |
| V* | 67.0% | Coming soon | Coming soon |

### Knowledge

- Winner: Directional only
- Claude Opus 4.5 public-lane score: 49 (Estimated · #57/160)
- Gemini 3 Flash public-lane score: 52.4 (Supported · #46/160)

| Benchmark | Claude Opus 4.5 | Gemini 3 Flash | Winner |
|-----------|-----------|-----------|--------|
| GPQA | 87% | Coming soon | Coming soon |
| SuperGPQA | 70.6% | Coming soon | Coming soon |
| MMLU-Pro | 89.5% | Coming soon | Coming soon |
| MMLU-Redux | 96.6% | Coming soon | Coming soon |
| C-Eval | 92.2% | Coming soon | Coming soon |
| HLE | 30.8% | Coming soon | Coming soon |
| GPQA Diamond (Vals) | Coming soon | 87.9% | Coming soon |
| MMLU-Pro (Vals) | Coming soon | 88.6% | Coming soon |

### Multilingual

- Winner: Not comparable
- Claude Opus 4.5 public-lane score: 82.9 (#2/12)
- Gemini 3 Flash public-lane score: Coming soon

| Benchmark | Claude Opus 4.5 | Gemini 3 Flash | Winner |
|-----------|-----------|-----------|--------|
| MMLU-ProX | 85.7% | Coming soon | Coming soon |
| NOVA-63 | 56.7% | Coming soon | Coming soon |

### Instruction Following

- Winner: Directional only
- Claude Opus 4.5 public-lane score: 30.6 (#114/124)
- Gemini 3 Flash public-lane score: 64.7 (#70/124)

| Benchmark | Claude Opus 4.5 | Gemini 3 Flash | Winner |
|-----------|-----------|-----------|--------|
| IFEval | 90.9% | Coming soon | Coming soon |
| IFBench | 58% | Coming soon | Coming soon |

### Mathematics

- Winner: Not comparable
- Claude Opus 4.5 public-lane score: 57.9 (#6/7)
- Gemini 3 Flash public-lane score: 50 (Unranked · 2 rankable rows)

| Benchmark | Claude Opus 4.5 | Gemini 3 Flash | Winner |
|-----------|-----------|-----------|--------|
| AIME26 | 95.1% | Coming soon | Coming soon |
| HMMT Feb 2025 | 92.9% | Coming soon | Coming soon |
| HMMT Nov 2025 | 93.3% | Coming soon | Coming soon |
| HMMT Feb 2026 | 85.3% | Coming soon | Coming soon |
| MMAnswerBench | 84.0% | Coming soon | Coming soon |
| FrontierMath v2 (Tiers 1-3) | 20.690% | 35.640% | Gemini 3 Flash |
| FrontierMath v2 (Tier 4) | 4.167% | 4.167% | Tie |

## FAQ

### Which is better overall, Claude Opus 4.5 or Gemini 3 Flash?

Claude Opus 4.5 is ahead overall on BenchLM right now.

### Where is the biggest gap between Claude Opus 4.5 and Gemini 3 Flash?

The widest category gap is in multimodal & grounded, where the averages are 23.5 for Claude Opus 4.5 and 75.8 for Gemini 3 Flash.

### How many benchmarks does Claude Opus 4.5 cover on BenchLM?

Claude Opus 4.5 currently has 45 sourced benchmark scores on BenchLM.

### How many benchmarks does Gemini 3 Flash cover on BenchLM?

Gemini 3 Flash currently has 11 sourced benchmark scores on BenchLM.

## Related Comparisons

- [Claude Opus 4.5 vs Claude Opus 4.5 Thinking](/compare/claude-opus-4-5-vs-claude-opus-4-5-thinking)
- [Gemini 3 Flash vs Claude Opus 4.5 Thinking](/compare/claude-opus-4-5-thinking-vs-gemini-3-flash)
- [Claude Opus 4.5 vs GPT-6 Astra](/compare/claude-opus-4-5-vs-gpt-6-astra)
- [Gemini 3 Flash vs GPT-6 Astra](/compare/gemini-3-flash-vs-gpt-6-astra)

## Explore More

- [Claude Opus 4.5 profile](/models/claude-opus-4-5)
- [Gemini 3 Flash profile](/models/gemini-3-flash)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)