# Grok 4.5 vs Mistral Medium 3.5 128B

> Side-by-side benchmark comparison for Grok 4.5 and Mistral Medium 3.5 128B across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/grok-4-5-vs-mistral-medium-3-5-128b
- Last updated: October 7, 2026

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

## Quick Verdict

Grok 4.5 leads by point estimate. Conditional score ranges do not establish rank confidence. Choose using the category evidence and your own workload tests.

## Summary

- Grok 4.5 has the higher overall point estimate 63.97 to 35.36. Conditional score ranges do not establish rank confidence.
- The clearest category separation is in agentic, where the averages are 57.6 for Grok 4.5 and 19.3 for Mistral Medium 3.5 128B.
- The biggest single benchmark swing is GPQA Diamond (Vals) in Knowledge, with scores of 92.9% and 34.8%.
- Grok 4.5 is the cheaper option on output tokens, which matters if you expect large responses or heavy interactive use.
- Grok 4.5 also has the larger context window at 500K.

## Model Snapshot

| Property | Grok 4.5 | Mistral Medium 3.5 128B |
|----------|----------|----------|
| Creator | xAI | Mistral |
| Type | Proprietary | Open Weight |
| Reasoning | Reasoning | Reasoning |
| Context | 500K | 256K |
| Overall Score | 63.97 | 35.36 |
| Benchmarks Covered | 17 | 7 |
| Pricing (input/output) | $2.00 / $6.00 | $1.50 / $7.50 |

## Category Breakdown

### Agentic

- Winner: Grok 4.5
- Grok 4.5 public-lane score: 57.6 (Supported · #29/122)
- Mistral Medium 3.5 128B public-lane score: 19.3 (Supported · #102/122)

| Benchmark | Grok 4.5 | Mistral Medium 3.5 128B | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 3.0 | 15.7% | Coming soon | Coming soon |
| Terminal-Bench 2.1 | 83.3% | Coming soon | Coming soon |
| deepSwe | 53% | Coming soon | Coming soon |
| Terminal-Bench 2.1 (Vals) | 67.8% | 39.0% | Grok 4.5 |
| τ³-bench results | Coming soon | 91.4% | Coming soon |
| Gert Labs | Coming soon | 39.10% | Coming soon |

### Coding

- Winner: Directional only
- Grok 4.5 public-lane score: 57.7 (Supported · #27/146)
- Mistral Medium 3.5 128B public-lane score: 24.6 (Estimated · #108/146)

| Benchmark | Grok 4.5 | Mistral Medium 3.5 128B | Winner |
|-----------|-----------|-----------|--------|
| SWE-bench Pro | 64.7% | Coming soon | Coming soon |
| SWE Multilingual | 78% | Coming soon | Coming soon |
| Terminal-Bench 2.1 | 83.3% | Coming soon | Coming soon |
| CursorBench 3.2 | 66.7% | Coming soon | Coming soon |
| VulcanBench v3 | 89.9% | Coming soon | Coming soon |
| LiveCodeBench (Vals) | 87.4% | Coming soon | Coming soon |
| SWE-bench (Vals) | 86.6% | 66.4% | Grok 4.5 |
| PostTrainBench v1.1 | 23.4% | Coming soon | Coming soon |
| SWE-bench Verified | Coming soon | 77.6% | Coming soon |

### Reasoning

- Winner: Not comparable
- Grok 4.5 public-lane score: 50.4 (#28/28)
- Mistral Medium 3.5 128B public-lane score: 69.9 (Unranked · 2 rankable rows)

| Benchmark | Grok 4.5 | Mistral Medium 3.5 128B | Winner |
|-----------|-----------|-----------|--------|
| ARC-AGI-2 | 52.6% | Coming soon | Coming soon |
| ARC-AGI-3 | 0.3% | Coming soon | Coming soon |
| ARC-AGI-1 | 85.67% | Coming soon | Coming soon |

### Multimodal & Grounded

- Winner: Not comparable
- Grok 4.5 public-lane score: 79.5 (Unranked · 1 rankable row)
- Mistral Medium 3.5 128B public-lane score: 56.7 (Unranked · 1 rankable row)

### Knowledge

- Winner: Grok 4.5
- Grok 4.5 public-lane score: 67 (Supported · #19/174)
- Mistral Medium 3.5 128B public-lane score: 30.8 (Supported · #137/174)

| Benchmark | Grok 4.5 | Mistral Medium 3.5 128B | Winner |
|-----------|-----------|-----------|--------|
| GPQA Diamond (Vals) | 92.9% | 34.8% | Grok 4.5 |
| MMLU-Pro (Vals) | 89.2% | 75.3% | Grok 4.5 |

### Instruction Following

- Winner: Not comparable
- Grok 4.5 public-lane score: Coming soon
- Mistral Medium 3.5 128B public-lane score: 82.6 (#47/125)

## FAQ

### Which is better overall, Grok 4.5 or Mistral Medium 3.5 128B?

Grok 4.5 has the higher overall point estimate. Conditional score ranges do not establish rank confidence.

### Where is the biggest gap between Grok 4.5 and Mistral Medium 3.5 128B?

The widest category gap is in agentic, where the averages are 57.6 for Grok 4.5 and 19.3 for Mistral Medium 3.5 128B.

### How many benchmarks does Grok 4.5 cover on BenchLM?

Grok 4.5 currently has 17 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

- [Grok 4.5 vs Claude Opus 5.5](/compare/claude-opus-5-5-vs-grok-4-5)
- [Mistral Medium 3.5 128B vs Claude Opus 5.5](/compare/claude-opus-5-5-vs-mistral-medium-3-5-128b)
- [Grok 4.5 vs GPT-6 Astra](/compare/gpt-6-astra-vs-grok-4-5)
- [Mistral Medium 3.5 128B vs GPT-6 Astra](/compare/gpt-6-astra-vs-mistral-medium-3-5-128b)

## Explore More

- [Grok 4.5 profile](/models/grok-4-5)
- [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)