# Gemini 3.1 Flash-Lite vs Mistral Medium 3.5 128B

> Side-by-side benchmark comparison for Gemini 3.1 Flash-Lite and Mistral Medium 3.5 128B across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/gemini-3-1-flash-lite-vs-mistral-medium-3-5-128b
- Last updated: September 29, 2026

- Shared sourced benchmarks: 5
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.7

## Quick Verdict

Pick Gemini 3.1 Flash-Lite 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 3.1 Flash-Lite leads overall 50.01 to 36.09.
- The clearest category separation is in multimodal & grounded, where the averages are 38.5 for Gemini 3.1 Flash-Lite and 56.7 for Mistral Medium 3.5 128B.
- The biggest single benchmark swing is GPQA Diamond (Vals) in Knowledge, with scores of 81.1% and 34.8%.
- Gemini 3.1 Flash-Lite is the cheaper option on output tokens, which matters if you expect large responses or heavy interactive use.
- Gemini 3.1 Flash-Lite also has the larger context window at 1M.

## Model Snapshot

| Property | Gemini 3.1 Flash-Lite | Mistral Medium 3.5 128B |
|----------|----------|----------|
| Creator | Google | Mistral |
| Type | Proprietary | Open Weight |
| Reasoning | Non-Reasoning | Reasoning |
| Context | 1M | 256K |
| Overall Score | 50.01 | 36.09 |
| Benchmarks Covered | 8 | 7 |
| Pricing (input/output) | $0.25 / $1.50 | $1.50 / $7.50 |

## Category Breakdown

### Agentic

- Winner: Directional only
- Gemini 3.1 Flash-Lite public-lane score: 30 (Estimated · #80/117)
- Mistral Medium 3.5 128B public-lane score: 19.7 (Supported · #100/117)

| Benchmark | Gemini 3.1 Flash-Lite | Mistral Medium 3.5 128B | Winner |
|-----------|-----------|-----------|--------|
| Gert Labs | 38.46% | 39.10% | Mistral Medium 3.5 128B |
| Terminal-Bench 2.1 (Vals) | 34.1% | 39.0% | Mistral Medium 3.5 128B |
| τ³-bench results | Coming soon | 91.4% | Coming soon |

### Coding

- Winner: Directional only
- Gemini 3.1 Flash-Lite public-lane score: 27.7 (Estimated · #97/143)
- Mistral Medium 3.5 128B public-lane score: 26.6 (Estimated · #102/143)

| Benchmark | Gemini 3.1 Flash-Lite | Mistral Medium 3.5 128B | Winner |
|-----------|-----------|-----------|--------|
| Vibe Code Bench | 0.00% | Coming soon | Coming soon |
| LiveCodeBench (Vals) | 80.1% | Coming soon | Coming soon |
| SWE-bench (Vals) | 62.8% | 66.4% | Mistral Medium 3.5 128B |
| SWE-bench Verified | Coming soon | 77.6% | Coming soon |

### Reasoning

- Winner: Not comparable
- Gemini 3.1 Flash-Lite public-lane score: Coming soon
- Mistral Medium 3.5 128B public-lane score: 69.9 (Unranked · 2 rankable rows)

### Multimodal & Grounded

- Winner: Not comparable
- Gemini 3.1 Flash-Lite public-lane score: 38.5 (Unranked · 1 rankable row)
- Mistral Medium 3.5 128B public-lane score: 56.7 (Unranked · 1 rankable row)

| Benchmark | Gemini 3.1 Flash-Lite | Mistral Medium 3.5 128B | Winner |
|-----------|-----------|-----------|--------|
| CharXiv | 73.2% | Coming soon | Coming soon |

### Knowledge

- Winner: Directional only
- Gemini 3.1 Flash-Lite public-lane score: 47.6 (Estimated · #72/169)
- Mistral Medium 3.5 128B public-lane score: 33.6 (Supported · #121/169)

| Benchmark | Gemini 3.1 Flash-Lite | Mistral Medium 3.5 128B | Winner |
|-----------|-----------|-----------|--------|
| GPQA Diamond (Vals) | 81.1% | 34.8% | Gemini 3.1 Flash-Lite |
| MMLU-Pro (Vals) | 86.2% | 75.3% | Gemini 3.1 Flash-Lite |

### Instruction Following

- Winner: Not comparable
- Gemini 3.1 Flash-Lite public-lane score: Coming soon
- Mistral Medium 3.5 128B public-lane score: 82.6 (#48/124)

## FAQ

### Which is better overall, Gemini 3.1 Flash-Lite or Mistral Medium 3.5 128B?

Gemini 3.1 Flash-Lite is ahead overall on BenchLM right now.

### Where is the biggest gap between Gemini 3.1 Flash-Lite and Mistral Medium 3.5 128B?

The widest category gap is in multimodal & grounded, where the averages are 38.5 for Gemini 3.1 Flash-Lite and 56.7 for Mistral Medium 3.5 128B.

### How many benchmarks does Gemini 3.1 Flash-Lite cover on BenchLM?

Gemini 3.1 Flash-Lite currently has 8 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 3.1 Flash-Lite vs GPT-6 Astra](/compare/gemini-3-1-flash-lite-vs-gpt-6-astra)
- [Mistral Medium 3.5 128B vs GPT-6 Astra](/compare/gpt-6-astra-vs-mistral-medium-3-5-128b)
- [Gemini 3.1 Flash-Lite vs Claude Opus 5.5](/compare/claude-opus-5-5-vs-gemini-3-1-flash-lite)
- [Mistral Medium 3.5 128B vs Claude Opus 5.5](/compare/claude-opus-5-5-vs-mistral-medium-3-5-128b)

## Explore More

- [Gemini 3.1 Flash-Lite profile](/models/gemini-3-1-flash-lite)
- [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)