# Mistral Medium 3.5 128B vs Beam

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

- Canonical page: https://benchlm.ai/compare/mistral-medium-3-5-128b-vs-reflection-beam
- Last updated: October 5, 2026

- Shared sourced benchmarks: 1
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.8

## Quick Verdict

Evidence is too thin for a benchmark verdict: Mistral Medium 3.5 128B and Beam share only 1 sourced benchmark row.

## Summary

- Only 1 shared sourced benchmark row is available. That is not enough for a broad capability verdict, so this mirror does not name an overall winner.
- Beam has the lower published output-token price.
- Mistral Medium 3.5 128B has the larger published context window at 256K.

## Model Snapshot

| Property | Mistral Medium 3.5 128B | Beam |
|----------|----------|----------|
| Creator | Mistral | Reflection AI |
| Type | Open Weight | Pending |
| Reasoning | Reasoning | Reasoning |
| Context | 256K | null |
| Independent public score (not head-to-head) | 35.36 | null |
| Benchmarks Covered | 7 | 16 |
| Pricing (input/output) | $1.50 / $7.50 | Pricing unavailable / Pricing unavailable |

## Category Breakdown

### Agentic

- Winner: Insufficient shared evidence
- Mistral Medium 3.5 128B public-lane score: 19.3 (Supported · #98/119)
- Beam public-lane score: Coming soon

| Benchmark | Mistral Medium 3.5 128B | Beam | Winner |
|-----------|-----------|-----------|--------|
| τ³-bench results | 91.4% | Coming soon | Coming soon |
| Gert Labs | 39.10% | Coming soon | Coming soon |
| Terminal-Bench 2.1 (Vals) | 39.0% | Coming soon | Coming soon |
| Terminal-Bench 2.1 | Coming soon | 80.1% | Coming soon |
| MCP Atlas | Coming soon | 78.7% | Coming soon |
| BrowseComp | Coming soon | 77.4% | Coming soon |
| DeepSearchQA | Coming soon | 80.1% | Coming soon |

### Coding

- Winner: Insufficient shared evidence
- Mistral Medium 3.5 128B public-lane score: 24.6 (Estimated · #105/144)
- Beam public-lane score: Coming soon

| Benchmark | Mistral Medium 3.5 128B | Beam | Winner |
|-----------|-----------|-----------|--------|
| SWE-bench Verified | 77.6% | 80.9% | Beam |
| SWE-bench (Vals) | 66.4% | Coming soon | Coming soon |
| DeepSWE | Coming soon | 44.4% | Coming soon |
| SWE-bench Pro | Coming soon | 65.5% | Coming soon |
| Terminal-Bench 2.1 | Coming soon | 80.1% | Coming soon |
| SWE-Atlas Codebase QnA | Coming soon | 34.6% | Coming soon |
| SWE Multilingual | Coming soon | 78% | Coming soon |
| SciCode | Coming soon | 49.7% | Coming soon |

### Reasoning

- Winner: Insufficient shared evidence
- Mistral Medium 3.5 128B public-lane score: 69.9 (Unranked · 2 rankable rows)
- Beam public-lane score: Coming soon

| Benchmark | Mistral Medium 3.5 128B | Beam | Winner |
|-----------|-----------|-----------|--------|
| LongBench v2 | Coming soon | 65.5% | Coming soon |

### Multimodal & Grounded

- Winner: Insufficient shared evidence
- Mistral Medium 3.5 128B public-lane score: 56.7 (Unranked · 1 rankable row)
- Beam public-lane score: Coming soon

### Knowledge

- Winner: Insufficient shared evidence
- Mistral Medium 3.5 128B public-lane score: 32.9 (Supported · #126/171)
- Beam public-lane score: Coming soon

| Benchmark | Mistral Medium 3.5 128B | Beam | Winner |
|-----------|-----------|-----------|--------|
| GPQA Diamond (Vals) | 34.8% | Coming soon | Coming soon |
| MMLU-Pro (Vals) | 75.3% | Coming soon | Coming soon |
| GPQA-D | Coming soon | 90.5% | Coming soon |
| HLE w/o tools | Coming soon | 36.2% | Coming soon |

### Instruction Following

- Winner: Insufficient shared evidence
- Mistral Medium 3.5 128B public-lane score: 82.6 (#46/125)
- Beam public-lane score: Coming soon

| Benchmark | Mistral Medium 3.5 128B | Beam | Winner |
|-----------|-----------|-----------|--------|
| IFBench | Coming soon | 79.7% | Coming soon |

### Mathematics

- Winner: Insufficient shared evidence
- Mistral Medium 3.5 128B public-lane score: Coming soon
- Beam public-lane score: Coming soon

| Benchmark | Mistral Medium 3.5 128B | Beam | Winner |
|-----------|-----------|-----------|--------|
| AIME26 | Coming soon | 97.8% | Coming soon |

## FAQ

### Is there enough evidence to pick between Mistral Medium 3.5 128B and Beam?

Not yet. The models share only 1 sourced benchmark row, so this mirror reports the available measurements and metadata without naming a broad winner.

### What can I compare safely on this page?

Published pricing, context windows, model type, and individual shared benchmark rows are directly comparable. Independent overall scores and non-overlapping benchmark coverage are labeled separately and should not be read as a controlled head-to-head result.

## Related Comparisons

- [Mistral Medium 3.5 128B vs Claude Opus 5.5](/compare/claude-opus-5-5-vs-mistral-medium-3-5-128b)
- [Beam vs Claude Opus 5.5](/compare/claude-opus-5-5-vs-reflection-beam)
- [Mistral Medium 3.5 128B vs GPT-6 Astra](/compare/gpt-6-astra-vs-mistral-medium-3-5-128b)
- [Beam vs GPT-6 Astra](/compare/gpt-6-astra-vs-reflection-beam)

## Explore More

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