# Claude Mythos 5 vs Gemini 3.5 Flash

> Side-by-side benchmark comparison for Claude Mythos 5 and Gemini 3.5 Flash across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

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

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

## Quick Verdict

Pick Claude Mythos 5 if you want the stronger benchmark profile. Gemini 3.5 Flash only makes more sense when its price, context window, or workload-specific category wins matter more than the overall score.

## Summary

- Claude Mythos 5 leads overall 85 to 70.
- The clearest category separation is in multimodal & grounded, where the averages are 85.1 for Claude Mythos 5 and 86.9 for Gemini 3.5 Flash.
- The biggest single benchmark swing is SWE-bench Pro in Coding, with scores of 80.3% and 55.1%.
- Gemini 3.5 Flash is the cheaper option on output tokens, which matters if you expect large responses or heavy interactive use.

## Model Snapshot

| Property | Claude Mythos 5 | Gemini 3.5 Flash |
|----------|----------|----------|
| Creator | Anthropic | Google |
| Type | Proprietary | Proprietary |
| Reasoning | Reasoning | Reasoning |
| Context | 1M+ | 1M |
| Overall Score | null | 70 |
| Benchmarks Covered | 15 | 27 |
| Pricing (input/output) | $10.00 / $50.00 | $1.50 / $9.00 |

## Category Breakdown

### Agentic

- Winner: Coming soon
- Claude Mythos 5 public-lane score: Coming soon
- Gemini 3.5 Flash public-lane score: 50.6 (Supported · #61/151)

| Benchmark | Claude Mythos 5 | Gemini 3.5 Flash | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 2.0 | 88% | 76.2% | Claude Mythos 5 |
| OSWorld-Verified | 85% | 78.4% | Claude Mythos 5 |
| BrowseComp | 88% | Coming soon | Coming soon |
| CyberGym | 83.8% | Coming soon | Coming soon |
| MCP Atlas | Coming soon | 83.6% | Coming soon |
| Toolathlon | Coming soon | 56.5% | Coming soon |
| Finance Agent v2 | Coming soon | 57.9% | Coming soon |
| Gert Labs | Coming soon | 61.85% | Coming soon |
| ResearchClawBench | Coming soon | 18.0% | Coming soon |
| Terminal-Bench 2.1 (Vals) | Coming soon | 74.2% | Coming soon |

### Coding

- Winner: Coming soon
- Claude Mythos 5 public-lane score: Coming soon
- Gemini 3.5 Flash public-lane score: 57.7 (Supported · #34/183)

| Benchmark | Claude Mythos 5 | Gemini 3.5 Flash | Winner |
|-----------|-----------|-----------|--------|
| SWE-bench Verified | 95.5% | Coming soon | Coming soon |
| SWE-bench Pro | 80.3% | 55.1% | Claude Mythos 5 |
| Terminal-Bench 2.0 | 88.0% | 76.2% | Claude Mythos 5 |
| Vibe Code Bench | Coming soon | 48.68% | Coming soon |
| cursorBench31 | Coming soon | 49.8% | Coming soon |
| cursorBench32 | Coming soon | 48.8% | Coming soon |
| LiveCodeBench (Vals) | Coming soon | 87.6% | Coming soon |
| SWE-bench (Vals) | Coming soon | 78.8% | Coming soon |

### Multimodal & Grounded

- Winner: Coming soon
- Claude Mythos 5 public-lane score: 85.1 (Unranked · 3 rankable rows)
- Gemini 3.5 Flash public-lane score: 86.9 (#6/48)

| Benchmark | Claude Mythos 5 | Gemini 3.5 Flash | Winner |
|-----------|-----------|-----------|--------|
| SWE-bench Multimodal | 54.9% | Coming soon | Coming soon |
| CharXiv | 93.5% | 84.2% | Claude Mythos 5 |
| CharXiv w/o tools | 88.9% | Coming soon | Coming soon |
| MMMU-Pro | Coming soon | 83.6% | Coming soon |
| Blueprint-Bench 2 | Coming soon | 33.6% | Coming soon |

### Reasoning

- Winner: Coming soon
- Claude Mythos 5 public-lane score: Coming soon
- Gemini 3.5 Flash public-lane score: 60.3 (#17/22)

| Benchmark | Claude Mythos 5 | Gemini 3.5 Flash | Winner |
|-----------|-----------|-----------|--------|
| MRCRv2 | Coming soon | 77.3% | Coming soon |
| MRCR 1M | Coming soon | 26.6% | Coming soon |
| ARC-AGI-2 | Coming soon | 72.1% | Coming soon |

### Knowledge

- Winner: Coming soon
- Claude Mythos 5 public-lane score: Coming soon
- Gemini 3.5 Flash public-lane score: 68.5 (Supported · #19/181)

| Benchmark | Claude Mythos 5 | Gemini 3.5 Flash | Winner |
|-----------|-----------|-----------|--------|
| GPQA | 94.1% | Coming soon | Coming soon |
| HLE | 64.5% | 40.2% | Claude Mythos 5 |
| HLE w/o tools | 59% | Coming soon | Coming soon |
| GPQA-D | Coming soon | 92.7% | Coming soon |
| GPQA Diamond (Vals) | Coming soon | 92.7% | Coming soon |
| MMLU-Pro (Vals) | Coming soon | 89.5% | Coming soon |

### Instruction Following

- Winner: Coming soon
- Claude Mythos 5 public-lane score: Coming soon
- Gemini 3.5 Flash public-lane score: 86.9 (#34/120)

### Multilingual

- Winner: Coming soon
- Claude Mythos 5 public-lane score: Coming soon
- Gemini 3.5 Flash public-lane score: Coming soon

| Benchmark | Claude Mythos 5 | Gemini 3.5 Flash | Winner |
|-----------|-----------|-----------|--------|
| SWE Multilingual | 92.2% | Coming soon | Coming soon |

### Mathematics

- Winner: Coming soon
- Claude Mythos 5 public-lane score: Coming soon
- Gemini 3.5 Flash public-lane score: 55.2 (Unranked · 2 rankable rows)

| Benchmark | Claude Mythos 5 | Gemini 3.5 Flash | Winner |
|-----------|-----------|-----------|--------|
| USAMO 2026 | 97.6% | Coming soon | Coming soon |
| FrontierMath v2 (Tiers 1-3) | Coming soon | 38.966% | Coming soon |
| FrontierMath v2 (Tier 4) | Coming soon | 14.583% | Coming soon |

## FAQ

### Which is better overall, Claude Mythos 5 or Gemini 3.5 Flash?

Claude Mythos 5 is ahead overall on BenchLM right now.

### Where is the biggest gap between Claude Mythos 5 and Gemini 3.5 Flash?

The widest category gap is in multimodal & grounded, where the averages are 85.1 for Claude Mythos 5 and 86.9 for Gemini 3.5 Flash.

### How many benchmarks does Claude Mythos 5 cover on BenchLM?

Claude Mythos 5 currently has 15 sourced benchmark scores on BenchLM.

### How many benchmarks does Gemini 3.5 Flash cover on BenchLM?

Gemini 3.5 Flash currently has 27 sourced benchmark scores on BenchLM.

## Related Comparisons

- [Claude Mythos 5 vs Claude Mythos 5.1](/compare/claude-mythos-5-vs-claude-mythos-5-1)
- [Gemini 3.5 Flash vs Claude Mythos 5.1](/compare/claude-mythos-5-1-vs-gemini-3-5-flash)
- [Claude Mythos 5 vs Claude Mythos Preview](/compare/claude-mythos-5-vs-claude-mythos-preview)
- [Gemini 3.5 Flash vs Claude Mythos Preview](/compare/claude-mythos-preview-vs-gemini-3-5-flash)

## Explore More

- [Claude Mythos 5 profile](/models/claude-mythos-5)
- [Gemini 3.5 Flash profile](/models/gemini-3-5-flash)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)