# DeepSeek V4 Flash 0731 vs Mercury 2.5

> Side-by-side benchmark comparison for DeepSeek V4 Flash 0731 and Mercury 2.5 across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/deepseek-v4-flash-0731-vs-mercury-2-5
- 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: DeepSeek V4 Flash 0731 and Mercury 2.5 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.
- DeepSeek V4 Flash 0731 has the larger published context window at 1M.

## Model Snapshot

| Property | DeepSeek V4 Flash 0731 | Mercury 2.5 |
|----------|----------|----------|
| Creator | DeepSeek | Inception |
| Type | Proprietary | Proprietary |
| Reasoning | Reasoning | Reasoning |
| Context | 1M | 260K |
| Independent public score (not head-to-head) | null | null |
| Benchmarks Covered | 40 | 5 |
| Pricing (input/output) | $0.14 / $0.28 | $0.04 / $0.15 |

## Category Breakdown

### Agentic

- Winner: Insufficient shared evidence
- DeepSeek V4 Flash 0731 public-lane score: Coming soon
- Mercury 2.5 public-lane score: 44.5 (Estimated · #91/152)

| Benchmark | DeepSeek V4 Flash 0731 | Mercury 2.5 | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 2.0 | 56.9% | Coming soon | Coming soon |
| BrowseComp | 73.2% | Coming soon | Coming soon |
| HLE w/ tools | 45.1% | Coming soon | Coming soon |
| MCP Atlas | 69% | Coming soon | Coming soon |
| Toolathlon | 47.8% | Coming soon | Coming soon |
| Terminal-Bench 2.1 | 82.7% | Coming soon | Coming soon |
| CyberGym | 76.7% | Coming soon | Coming soon |
| Toolathlon-Verified | 70.3% | Coming soon | Coming soon |
| Agents' Last Exam | 25.2% | Coming soon | Coming soon |
| AutomationBench | 25.1% | Coming soon | Coming soon |
| Terminal-Bench 2.1 (Vals) | 67.0% | Coming soon | Coming soon |
| τ³-bench results | Coming soon | 96.0% | Coming soon |
| DeepSearchQA | Coming soon | 34.0% | Coming soon |

### Coding

- Winner: Insufficient shared evidence
- DeepSeek V4 Flash 0731 public-lane score: Coming soon
- Mercury 2.5 public-lane score: 47.8 (Estimated · #73/151)

| Benchmark | DeepSeek V4 Flash 0731 | Mercury 2.5 | Winner |
|-----------|-----------|-----------|--------|
| LiveCodeBench Pass@1-COT | 91.6% | Coming soon | Coming soon |
| Codeforces | 3052.0 | Coming soon | Coming soon |
| SWE-bench Verified | 79% | Coming soon | Coming soon |
| SWE-bench Pro | 52.6% | Coming soon | Coming soon |
| SWE Multilingual | 73.3% | Coming soon | Coming soon |
| Terminal-Bench 2.0 | 56.9% | Coming soon | Coming soon |
| Terminal-Bench 2.1 | 82.7% | Coming soon | Coming soon |
| NL2Repo | 54.2% | Coming soon | Coming soon |
| deepSwe | 54.4% | Coming soon | Coming soon |
| DSBench-FullStack | 68.7% | Coming soon | Coming soon |
| DSBench-Hard | 59.6% | Coming soon | Coming soon |
| VulcanBench v3 | 88.4% | Coming soon | Coming soon |
| OpenHarmony Bench | 53.8% | Coming soon | Coming soon |
| LiveCodeBench (Vals) | 87.3% | Coming soon | Coming soon |
| SWE-bench (Vals) | 88.8% | Coming soon | Coming soon |
| SciCode | Coming soon | 38% | Coming soon |

### Reasoning

- Winner: Insufficient shared evidence
- DeepSeek V4 Flash 0731 public-lane score: Coming soon
- Mercury 2.5 public-lane score: 67.7 (Unranked · 1 rankable row)

| Benchmark | DeepSeek V4 Flash 0731 | Mercury 2.5 | Winner |
|-----------|-----------|-----------|--------|
| MRCR 1M | 78.7% | Coming soon | Coming soon |
| CorpusQA 1M | 60.5% | Coming soon | Coming soon |

### Knowledge

- Winner: Insufficient shared evidence
- DeepSeek V4 Flash 0731 public-lane score: Coming soon
- Mercury 2.5 public-lane score: 48.3 (Estimated · #94/182)

| Benchmark | DeepSeek V4 Flash 0731 | Mercury 2.5 | Winner |
|-----------|-----------|-----------|--------|
| MMLU-Pro | 86.2% | Coming soon | Coming soon |
| SimpleQA | 34.1% | Coming soon | Coming soon |
| Chinese-SimpleQA | 78.9% | Coming soon | Coming soon |
| GPQA | 88.1% | Coming soon | Coming soon |
| GPQA-D | 88.1% | 79.0% | DeepSeek V4 Flash 0731 |
| HLE | 34.8% | Coming soon | Coming soon |
| GPQA Diamond (Vals) | 89.9% | Coming soon | Coming soon |
| MMLU-Pro (Vals) | 86.2% | Coming soon | Coming soon |

### Instruction Following

- Winner: Insufficient shared evidence
- DeepSeek V4 Flash 0731 public-lane score: Coming soon
- Mercury 2.5 public-lane score: 80.1 (#53/121)

| Benchmark | DeepSeek V4 Flash 0731 | Mercury 2.5 | Winner |
|-----------|-----------|-----------|--------|
| IFBench | Coming soon | 77% | Coming soon |

### Mathematics

- Winner: Insufficient shared evidence
- DeepSeek V4 Flash 0731 public-lane score: 80 (Unranked · 4 rankable rows)
- Mercury 2.5 public-lane score: Coming soon

| Benchmark | DeepSeek V4 Flash 0731 | Mercury 2.5 | Winner |
|-----------|-----------|-----------|--------|
| HMMT Feb 2026 | 94.8% | Coming soon | Coming soon |
| IMOAnswerBench | 88.4% | Coming soon | Coming soon |
| Apex | 33.0% | Coming soon | Coming soon |
| Apex Shortlist | 85.7% | Coming soon | Coming soon |

## FAQ

### Is there enough evidence to pick between DeepSeek V4 Flash 0731 and Mercury 2.5?

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

- [DeepSeek V4 Flash 0731 vs Mercury 2.5 Preview](/compare/deepseek-v4-flash-0731-vs-mercury-2-5-preview)
- [Mercury 2.5 vs Mercury 2.5 Preview](/compare/mercury-2-5-vs-mercury-2-5-preview)
- [DeepSeek V4 Flash 0731 vs Claude Fable 5.1](/compare/claude-fable-5-1-vs-deepseek-v4-flash-0731)
- [Mercury 2.5 vs Claude Fable 5.1](/compare/claude-fable-5-1-vs-mercury-2-5)

## Explore More

- [DeepSeek V4 Flash 0731 profile](/models/deepseek-v4-flash-0731)
- [Mercury 2.5 profile](/models/mercury-2-5)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)