# Mercury 3 vs Mistral Medium 3.5 128B

> Side-by-side benchmark comparison for Mercury 3 and Mistral Medium 3.5 128B across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/mercury-3-vs-mistral-medium-3-5-128b
- Last updated: October 19, 2026

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

## Quick Verdict

Evidence is too thin for a benchmark verdict: Mercury 3 and Mistral Medium 3.5 128B 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.
- Mercury 3 has the lower published output-token price.
- Mercury 3 has the larger published context window at 1M.

## Model Snapshot

| Property | Mercury 3 | Mistral Medium 3.5 128B |
|----------|----------|----------|
| Creator | Inception | Mistral |
| Type | Proprietary | Open Weight |
| Reasoning | Reasoning | Reasoning |
| Context | 1M | 256K |
| Independent public score (not head-to-head) | null | 33.61 |
| Benchmarks Covered | 8 | 7 |
| Pricing (input/output) | $0.10 / $0.35 | $1.50 / $7.50 |

## Category Breakdown

### Agentic

- Winner: Insufficient shared evidence
- Mercury 3 public-lane score: Coming soon
- Mistral Medium 3.5 128B public-lane score: 19.9 (Supported · #111/130)

| Benchmark | Mercury 3 | Mistral Medium 3.5 128B | Winner |
|-----------|-----------|-----------|--------|
| τ³-bench results | 30.2% | 91.4% | Mistral Medium 3.5 128B |
| BrowseComp+ | 55.18% | Coming soon | Coming soon |
| DeepSearchQA | 71.3% | Coming soon | Coming soon |
| Gert Labs | Coming soon | 39.10% | Coming soon |
| Terminal-Bench 2.1 (Vals) | Coming soon | 39.0% | Coming soon |

### Coding

- Winner: Insufficient shared evidence
- Mercury 3 public-lane score: Coming soon
- Mistral Medium 3.5 128B public-lane score: 22.7 (Estimated · #115/151)

| Benchmark | Mercury 3 | Mistral Medium 3.5 128B | Winner |
|-----------|-----------|-----------|--------|
| DeepSWE | 46.3% | Coming soon | Coming soon |
| SWE-bench Verified | Coming soon | 77.6% | Coming soon |
| SWE-bench (Vals) | Coming soon | 66.4% | Coming soon |

### Reasoning

- Winner: Insufficient shared evidence
- Mercury 3 public-lane score: Coming soon
- Mistral Medium 3.5 128B public-lane score: 72.6 (Unranked · 2 rankable rows)

| Benchmark | Mercury 3 | Mistral Medium 3.5 128B | Winner |
|-----------|-----------|-----------|--------|
| MRCRv2 | 75.5% | Coming soon | Coming soon |

### Multimodal & Grounded

- Winner: Insufficient shared evidence
- Mercury 3 public-lane score: Coming soon
- Mistral Medium 3.5 128B public-lane score: 60.1 (Unranked · 1 rankable row)

### Knowledge

- Winner: Insufficient shared evidence
- Mercury 3 public-lane score: Coming soon
- Mistral Medium 3.5 128B public-lane score: 31.8 (Supported · #150/186)

| Benchmark | Mercury 3 | Mistral Medium 3.5 128B | Winner |
|-----------|-----------|-----------|--------|
| GPQA-D | 89.2% | Coming soon | Coming soon |
| GPQA Diamond (Vals) | Coming soon | 34.8% | Coming soon |
| MMLU-Pro (Vals) | Coming soon | 75.3% | Coming soon |

### Instruction Following

- Winner: Insufficient shared evidence
- Mercury 3 public-lane score: Coming soon
- Mistral Medium 3.5 128B public-lane score: 84 (#52/148)

| Benchmark | Mercury 3 | Mistral Medium 3.5 128B | Winner |
|-----------|-----------|-----------|--------|
| IFBench | 76.8% | Coming soon | Coming soon |
| MultiChallenge (provider reports) | 60.35% | Coming soon | Coming soon |

## FAQ

### Is there enough evidence to pick between Mercury 3 and Mistral Medium 3.5 128B?

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

- [Mercury 3 vs Claude Opus 5.5](/compare/claude-opus-5-5-vs-mercury-3)
- [Mistral Medium 3.5 128B vs Claude Opus 5.5](/compare/claude-opus-5-5-vs-mistral-medium-3-5-128b)
- [Mercury 3 vs GPT-6.1 Sol](/compare/gpt-6-1-sol-vs-mercury-3)
- [Mistral Medium 3.5 128B vs GPT-6.1 Sol](/compare/gpt-6-1-sol-vs-mistral-medium-3-5-128b)

## Explore More

- [Mercury 3 profile](/models/mercury-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)