# Grok 4.3 vs Mistral Medium 3.5 128B

> Side-by-side benchmark comparison for Grok 4.3 and Mistral Medium 3.5 128B across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/grok-4-3-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 Grok 4.3 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

- Grok 4.3 leads overall 59.73 to 30.13.
- The clearest category separation is in knowledge, where the averages are 57 for Grok 4.3 and 39 for Mistral Medium 3.5 128B.
- The biggest single benchmark swing is GPQA Diamond (Vals) in Knowledge, with scores of 91.4% and 34.8%.
- Grok 4.3 is the cheaper option on output tokens, which matters if you expect large responses or heavy interactive use.
- Grok 4.3 also has the larger context window at 1M.

## Model Snapshot

| Property | Grok 4.3 | Mistral Medium 3.5 128B |
|----------|----------|----------|
| Creator | xAI | Mistral |
| Type | Proprietary | Open Weight |
| Reasoning | Reasoning | Reasoning |
| Context | 1M | 256K |
| Overall Score | 59.73 | 30.13 |
| Benchmarks Covered | 7 | 7 |
| Pricing (input/output) | $1.25 / $2.50 | $1.50 / $7.50 |

## Category Breakdown

### Agentic

- Winner: Grok 4.3
- Grok 4.3 public-lane score: 26.9 (Supported · #144/152)
- Mistral Medium 3.5 128B public-lane score: 21.9 (Supported · #150/152)

| Benchmark | Grok 4.3 | Mistral Medium 3.5 128B | Winner |
|-----------|-----------|-----------|--------|
| Gert Labs | 43.86% | 39.10% | Grok 4.3 |
| ResearchClawBench | 12.4% | Coming soon | Coming soon |
| Terminal-Bench 2.1 (Vals) | 41.9% | 39.0% | Grok 4.3 |
| τ³-bench results | Coming soon | 91.4% | Coming soon |

### Coding

- Winner: Coming soon
- Grok 4.3 public-lane score: 33.6 (Supported · #131/151)
- Mistral Medium 3.5 128B public-lane score: 36.9 (Estimated · #127/151)

| Benchmark | Grok 4.3 | Mistral Medium 3.5 128B | Winner |
|-----------|-----------|-----------|--------|
| LiveCodeBench (Vals) | 84.5% | Coming soon | Coming soon |
| SWE-bench (Vals) | 71.4% | 66.4% | Grok 4.3 |
| SWE-bench Verified | Coming soon | 77.6% | Coming soon |

### Multimodal & Grounded

- Winner: Coming soon
- Grok 4.3 public-lane score: 65.6 (#25/48)
- Mistral Medium 3.5 128B public-lane score: 55.6 (Unranked · 1 rankable row)

### Reasoning

- Winner: Coming soon
- Grok 4.3 public-lane score: 65.2 (Unranked · 2 rankable rows)
- Mistral Medium 3.5 128B public-lane score: 68.6 (Unranked · 2 rankable rows)

### Knowledge

- Winner: Grok 4.3
- Grok 4.3 public-lane score: 57 (Supported · #44/183)
- Mistral Medium 3.5 128B public-lane score: 39 (Supported · #140/183)

| Benchmark | Grok 4.3 | Mistral Medium 3.5 128B | Winner |
|-----------|-----------|-----------|--------|
| GPQA Diamond (Vals) | 91.4% | 34.8% | Grok 4.3 |
| MMLU-Pro (Vals) | 85.8% | 75.3% | Grok 4.3 |

### Instruction Following

- Winner: Coming soon
- Grok 4.3 public-lane score: 94.4 (#2/123)
- Mistral Medium 3.5 128B public-lane score: 84 (#48/123)

## FAQ

### Which is better overall, Grok 4.3 or Mistral Medium 3.5 128B?

Grok 4.3 is ahead overall on BenchLM right now.

### Where is the biggest gap between Grok 4.3 and Mistral Medium 3.5 128B?

The widest category gap is in knowledge, where the averages are 57 for Grok 4.3 and 39 for Mistral Medium 3.5 128B.

### How many benchmarks does Grok 4.3 cover on BenchLM?

Grok 4.3 currently has 7 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 4.3 vs Claude Fable 5.1](/compare/claude-fable-5-1-vs-grok-4-3)
- [Mistral Medium 3.5 128B vs Claude Fable 5.1](/compare/claude-fable-5-1-vs-mistral-medium-3-5-128b)
- [Grok 4.3 vs GPT-6 Astra](/compare/gpt-6-astra-vs-grok-4-3)
- [Mistral Medium 3.5 128B vs GPT-6 Astra](/compare/gpt-6-astra-vs-mistral-medium-3-5-128b)

## Explore More

- [Grok 4.3 profile](/models/grok-4-3)
- [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)