# Gemini 3.8 Flash vs Mistral Medium 3.5 128B

> Side-by-side benchmark comparison for Gemini 3.8 Flash and Mistral Medium 3.5 128B across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/gemini-3-8-flash-vs-mistral-medium-3-5-128b
- Last updated: October 17, 2026

- Shared sourced benchmarks: 4
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.8

## Quick Verdict

Gemini 3.8 Flash leads by point estimate. Conditional score ranges do not establish rank confidence. Choose using the category evidence and your own workload tests.

## Summary

- Gemini 3.8 Flash has the higher overall point estimate 69.25 to 33.62. Conditional score ranges do not establish rank confidence.
- The clearest category separation is in agentic, where the averages are 65.9 for Gemini 3.8 Flash and 19.8 for Mistral Medium 3.5 128B.
- The biggest single benchmark swing is GPQA Diamond (Vals) in Knowledge, with scores of 94.4% and 34.8%.
- Gemini 3.8 Flash is the cheaper option on output tokens, which matters if you expect large responses or heavy interactive use.
- Gemini 3.8 Flash also has the larger context window at 1M.

## Model Snapshot

| Property | Gemini 3.8 Flash | Mistral Medium 3.5 128B |
|----------|----------|----------|
| Creator | Google | Mistral |
| Type | Proprietary | Open Weight |
| Reasoning | Reasoning | Reasoning |
| Context | 1M | 256K |
| Overall Score | 69.25 | 33.62 |
| Benchmarks Covered | 31 | 7 |
| Pricing (input/output) | $0.75 / $3.75 | $1.50 / $7.50 |

## Category Breakdown

### Agentic

- Winner: Gemini 3.8 Flash
- Gemini 3.8 Flash public-lane score: 65.9 (Supported · #16/128)
- Mistral Medium 3.5 128B public-lane score: 19.8 (Supported · #108/128)

| Benchmark | Gemini 3.8 Flash | Mistral Medium 3.5 128B | Winner |
|-----------|-----------|-----------|--------|
| Finance Agent v2 | 61.4% | Coming soon | Coming soon |
| Terminal-Bench 2.1 | 89.4% | Coming soon | Coming soon |
| Terminal-Bench 4.0 | 19.10% | Coming soon | Coming soon |
| OSWorld 2.0 | 59.0% | Coming soon | Coming soon |
| Terminal-Bench 2.1 (Vals) | 81.3% | 39.0% | Gemini 3.8 Flash |
| ApprenticeBench | 24% | Coming soon | Coming soon |
| Hermes Index | 38.1% | Coming soon | Coming soon |
| Hermes Bench | 62.2% | Coming soon | Coming soon |
| MazeBench | 4% | Coming soon | Coming soon |
| τ³-bench results | Coming soon | 91.4% | Coming soon |
| Gert Labs | Coming soon | 39.10% | Coming soon |

### Coding

- Winner: Directional only
- Gemini 3.8 Flash public-lane score: 61 (Supported · #17/150)
- Mistral Medium 3.5 128B public-lane score: 22.6 (Estimated · #114/150)

| Benchmark | Gemini 3.8 Flash | Mistral Medium 3.5 128B | Winner |
|-----------|-----------|-----------|--------|
| DeepSWE | 73.8% | Coming soon | Coming soon |
| Terminal-Bench 2.1 | 89.4% | Coming soon | Coming soon |
| CursorBench 3.2 | 69.2% | Coming soon | Coming soon |
| LiveCodeBench (Vals) | 89.5% | Coming soon | Coming soon |
| SWE-bench (Vals) | 80.0% | 66.4% | Gemini 3.8 Flash |
| FrontierSWE v2 | 19.6% | Coming soon | Coming soon |
| CursorBench 4.0 | 39.6% | Coming soon | Coming soon |
| Bug Hunt Bench | 18.0 fixes | Coming soon | Coming soon |
| SWE-bench Verified | Coming soon | 77.6% | Coming soon |

### Reasoning

- Winner: Not comparable
- Gemini 3.8 Flash public-lane score: 74.3 (#17/28)
- Mistral Medium 3.5 128B public-lane score: 73.5 (Unranked · 2 rankable rows)

| Benchmark | Gemini 3.8 Flash | Mistral Medium 3.5 128B | Winner |
|-----------|-----------|-----------|--------|
| ARC-AGI-1 | 98.50% | Coming soon | Coming soon |
| ARC-AGI-2 | 89.2% | Coming soon | Coming soon |
| ARC-AGI-3 | 10.4% | Coming soon | Coming soon |

### Multimodal & Grounded

- Winner: Not comparable
- Gemini 3.8 Flash public-lane score: 87.3 (#9/54)
- Mistral Medium 3.5 128B public-lane score: 60.1 (Unranked · 1 rankable row)

| Benchmark | Gemini 3.8 Flash | Mistral Medium 3.5 128B | Winner |
|-----------|-----------|-----------|--------|
| CharXiv w/o tools | 86.2% | Coming soon | Coming soon |
| LVBench | 87.1% | Coming soon | Coming soon |

### Knowledge

- Winner: Gemini 3.8 Flash
- Gemini 3.8 Flash public-lane score: 73.5 (Supported · #13/184)
- Mistral Medium 3.5 128B public-lane score: 31.8 (Supported · #148/184)

| Benchmark | Gemini 3.8 Flash | Mistral Medium 3.5 128B | Winner |
|-----------|-----------|-----------|--------|
| HLE-Verified | 54.9% | Coming soon | Coming soon |
| LABBench2 | 86.2% | Coming soon | Coming soon |
| BioMysteryBench (human-solvable) | 88.8% | Coming soon | Coming soon |
| BioMysteryBench (human-difficult) | 56.5% | Coming soon | Coming soon |
| GPQA Diamond (Vals) | 94.4% | 34.8% | Gemini 3.8 Flash |
| MMLU-Pro (Vals) | 90.2% | 75.3% | Gemini 3.8 Flash |

### Instruction Following

- Winner: Not comparable
- Gemini 3.8 Flash public-lane score: Coming soon
- Mistral Medium 3.5 128B public-lane score: 84 (#52/148)

| Benchmark | Gemini 3.8 Flash | Mistral Medium 3.5 128B | Winner |
|-----------|-----------|-----------|--------|
| Gray Swan IPI (15 attempts) | 5.5% | Coming soon | Coming soon |

### Mathematics

- Winner: Not comparable
- Gemini 3.8 Flash public-lane score: 69.7 (Unranked · 2 rankable rows)
- Mistral Medium 3.5 128B public-lane score: Coming soon

| Benchmark | Gemini 3.8 Flash | Mistral Medium 3.5 128B | Winner |
|-----------|-----------|-----------|--------|
| FrontierMath v2 (Tiers 1-3) | 68.421% | Coming soon | Coming soon |
| FrontierMath v2 (Tier 4) | 21.951% | Coming soon | Coming soon |

## FAQ

### Which is better overall, Gemini 3.8 Flash or Mistral Medium 3.5 128B?

Gemini 3.8 Flash has the higher overall point estimate. Conditional score ranges do not establish rank confidence.

### Where is the biggest gap between Gemini 3.8 Flash and Mistral Medium 3.5 128B?

The widest category gap is in agentic, where the averages are 65.9 for Gemini 3.8 Flash and 19.8 for Mistral Medium 3.5 128B.

### How many benchmarks does Gemini 3.8 Flash cover on BenchLM?

Gemini 3.8 Flash currently has 31 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 3.8 Flash vs Gemini 3.8 Flash Cyber](/compare/gemini-3-8-flash-vs-gemini-3-8-flash-cyber)
- [Mistral Medium 3.5 128B vs Gemini 3.8 Flash Cyber](/compare/gemini-3-8-flash-cyber-vs-mistral-medium-3-5-128b)
- [Gemini 3.8 Flash vs Claude Opus 5.5](/compare/claude-opus-5-5-vs-gemini-3-8-flash)
- [Mistral Medium 3.5 128B vs Claude Opus 5.5](/compare/claude-opus-5-5-vs-mistral-medium-3-5-128b)

## Explore More

- [Gemini 3.8 Flash profile](/models/gemini-3-8-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)