# Gemini 3 Flash vs Mistral Medium 3.5 128B

> Side-by-side benchmark comparison for Gemini 3 Flash and Mistral Medium 3.5 128B across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/gemini-3-flash-vs-mistral-medium-3-5-128b
- Last updated: September 10, 2026

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

## Quick Verdict

Pick Gemini 3 Flash if you want the stronger benchmark profile. Mistral Medium 3.5 128B only makes more sense when its price, context window, or workload-specific category wins matter more than the overall score.

## Summary

- Gemini 3 Flash leads overall 62.2 to 30.13.
- The clearest category separation is in multimodal & grounded, where the averages are 75.8 for Gemini 3 Flash and 55.6 for Mistral Medium 3.5 128B.
- The biggest single benchmark swing is GPQA Diamond (Vals) in Knowledge, with scores of 87.9% and 34.8%.
- 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 | Gemini 3 Flash | Mistral Medium 3.5 128B |
|----------|----------|----------|
| Creator | Google | Mistral |
| Type | Proprietary | Open Weight |
| Reasoning | Non-Reasoning | Reasoning |
| Context | 1M | 256K |
| Overall Score | 62.2 | 30.13 |
| Benchmarks Covered | 11 | 7 |
| Pricing (input/output) | $0.50 / $3.00 | $1.50 / $7.50 |

## Category Breakdown

### Agentic

- Winner: Gemini 3 Flash
- Gemini 3 Flash public-lane score: 34 (Supported · #134/152)
- Mistral Medium 3.5 128B public-lane score: 21.9 (Supported · #150/152)

| Benchmark | Gemini 3 Flash | Mistral Medium 3.5 128B | Winner |
|-----------|-----------|-----------|--------|
| Claw-Eval | 49.2% | Coming soon | Coming soon |
| Gert Labs | 56.63% | 39.10% | Gemini 3 Flash |
| JobBench | 11.4% | Coming soon | Coming soon |
| Terminal-Bench 2.1 (Vals) | 53.9% | 39.0% | Gemini 3 Flash |
| τ³-bench results | Coming soon | 91.4% | Coming soon |

### Coding

- Winner: Coming soon
- Gemini 3 Flash public-lane score: 41.5 (Supported · #108/151)
- Mistral Medium 3.5 128B public-lane score: 36.9 (Estimated · #127/151)

| Benchmark | Gemini 3 Flash | Mistral Medium 3.5 128B | Winner |
|-----------|-----------|-----------|--------|
| Vibe Code Bench | 20.20% | Coming soon | Coming soon |
| LiveCodeBench (Vals) | 85.6% | Coming soon | Coming soon |
| SWE-bench (Vals) | 75.0% | 66.4% | Gemini 3 Flash |
| SWE-bench Verified | Coming soon | 77.6% | Coming soon |

### Multimodal & Grounded

- Winner: Coming soon
- Gemini 3 Flash public-lane score: 75.8 (Unranked · 1 rankable row)
- Mistral Medium 3.5 128B public-lane score: 55.6 (Unranked · 1 rankable row)

### Reasoning

- Winner: Coming soon
- Gemini 3 Flash public-lane score: 59 (Unranked · 2 rankable rows)
- Mistral Medium 3.5 128B public-lane score: 68.6 (Unranked · 2 rankable rows)

### Knowledge

- Winner: Gemini 3 Flash
- Gemini 3 Flash public-lane score: 56.9 (Supported · #45/183)
- Mistral Medium 3.5 128B public-lane score: 39 (Supported · #140/183)

| Benchmark | Gemini 3 Flash | Mistral Medium 3.5 128B | Winner |
|-----------|-----------|-----------|--------|
| GPQA Diamond (Vals) | 87.9% | 34.8% | Gemini 3 Flash |
| MMLU-Pro (Vals) | 88.6% | 75.3% | Gemini 3 Flash |

### Instruction Following

- Winner: Coming soon
- Gemini 3 Flash public-lane score: 66.2 (#68/123)
- Mistral Medium 3.5 128B public-lane score: 84 (#48/123)

### Mathematics

- Winner: Coming soon
- Gemini 3 Flash public-lane score: 50.2 (Unranked · 2 rankable rows)
- Mistral Medium 3.5 128B public-lane score: Coming soon

| Benchmark | Gemini 3 Flash | Mistral Medium 3.5 128B | Winner |
|-----------|-----------|-----------|--------|
| FrontierMath v2 (Tiers 1-3) | 35.640% | Coming soon | Coming soon |
| FrontierMath v2 (Tier 4) | 4.167% | Coming soon | Coming soon |

## FAQ

### Which is better overall, Gemini 3 Flash or Mistral Medium 3.5 128B?

Gemini 3 Flash is ahead overall on BenchLM right now.

### Where is the biggest gap between Gemini 3 Flash and Mistral Medium 3.5 128B?

The widest category gap is in multimodal & grounded, where the averages are 75.8 for Gemini 3 Flash and 55.6 for Mistral Medium 3.5 128B.

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

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

### How many benchmarks does Mistral Medium 3.5 128B cover on BenchLM?

Mistral Medium 3.5 128B currently has 7 sourced benchmark scores on BenchLM.

## Related Comparisons

- [Gemini 3 Flash vs Claude Fable 5.1](/compare/claude-fable-5-1-vs-gemini-3-flash)
- [Mistral Medium 3.5 128B vs Claude Fable 5.1](/compare/claude-fable-5-1-vs-mistral-medium-3-5-128b)
- [Gemini 3 Flash vs GPT-6 Astra](/compare/gemini-3-flash-vs-gpt-6-astra)
- [Mistral Medium 3.5 128B vs GPT-6 Astra](/compare/gpt-6-astra-vs-mistral-medium-3-5-128b)

## Explore More

- [Gemini 3 Flash profile](/models/gemini-3-flash)
- [Mistral Medium 3.5 128B profile](/models/mistral-medium-3-5-128b)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)