# Mercury 2.5 vs Mistral Medium 3.5 128B

> Side-by-side benchmark comparison for Mercury 2.5 and Mistral Medium 3.5 128B across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/mercury-2-5-vs-mistral-medium-3-5-128b
- Last updated: September 8, 2026

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

## Quick Verdict

Evidence is too thin for a benchmark verdict: Mercury 2.5 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 2.5 has the lower published output-token price.
- Mercury 2.5 has the larger published context window at 260K.

## Model Snapshot

| Property | Mercury 2.5 | Mistral Medium 3.5 128B |
|----------|----------|----------|
| Creator | Inception | Mistral |
| Type | Proprietary | Open Weight |
| Reasoning | Reasoning | Reasoning |
| Context | 260K | 256K |
| Independent public score (not head-to-head) | null | 30.11 |
| Benchmarks Covered | 5 | 7 |
| Pricing (input/output) | $0.04 / $0.15 | $1.50 / $7.50 |

## Category Breakdown

### Agentic

- Winner: Insufficient shared evidence
- Mercury 2.5 public-lane score: 44.5 (Estimated · #91/152)
- Mistral Medium 3.5 128B public-lane score: 21.9 (Supported · #150/152)

| Benchmark | Mercury 2.5 | Mistral Medium 3.5 128B | Winner |
|-----------|-----------|-----------|--------|
| τ³-bench results | 96.0% | 91.4% | Mercury 2.5 |
| DeepSearchQA | 34.0% | 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 2.5 public-lane score: 47.8 (Estimated · #73/151)
- Mistral Medium 3.5 128B public-lane score: 37.2 (Estimated · #126/151)

| Benchmark | Mercury 2.5 | Mistral Medium 3.5 128B | Winner |
|-----------|-----------|-----------|--------|
| SciCode | 38% | Coming soon | Coming soon |
| SWE-bench Verified | Coming soon | 77.6% | Coming soon |
| SWE-bench (Vals) | Coming soon | 66.4% | Coming soon |

### Multimodal & Grounded

- Winner: Insufficient shared evidence
- Mercury 2.5 public-lane score: Coming soon
- Mistral Medium 3.5 128B public-lane score: 55.6 (Unranked · 1 rankable row)

### Reasoning

- Winner: Insufficient shared evidence
- Mercury 2.5 public-lane score: 67.7 (Unranked · 1 rankable row)
- Mistral Medium 3.5 128B public-lane score: 68.6 (Unranked · 2 rankable rows)

### Knowledge

- Winner: Insufficient shared evidence
- Mercury 2.5 public-lane score: 48.3 (Estimated · #94/182)
- Mistral Medium 3.5 128B public-lane score: 39.3 (Supported · #139/182)

| Benchmark | Mercury 2.5 | Mistral Medium 3.5 128B | Winner |
|-----------|-----------|-----------|--------|
| GPQA-D | 79.0% | 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 2.5 public-lane score: 80.1 (#53/121)
- Mistral Medium 3.5 128B public-lane score: 84 (#47/121)

| Benchmark | Mercury 2.5 | Mistral Medium 3.5 128B | Winner |
|-----------|-----------|-----------|--------|
| IFBench | 77% | Coming soon | Coming soon |

## FAQ

### Is there enough evidence to pick between Mercury 2.5 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 2.5 vs Mercury 2.5 Preview](/compare/mercury-2-5-vs-mercury-2-5-preview)
- [Mistral Medium 3.5 128B vs Mercury 2.5 Preview](/compare/mercury-2-5-preview-vs-mistral-medium-3-5-128b)
- [Mercury 2.5 vs Claude Fable 5.1](/compare/claude-fable-5-1-vs-mercury-2-5)
- [Mistral Medium 3.5 128B vs Claude Fable 5.1](/compare/claude-fable-5-1-vs-mistral-medium-3-5-128b)

## Explore More

- [Mercury 2.5 profile](/models/mercury-2-5)
- [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)