# Mercury 2.5 vs o3

> Side-by-side benchmark comparison for Mercury 2.5 and o3 across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/mercury-2-5-vs-o3
- Last updated: September 8, 2026

- Shared sourced benchmarks: 0
- HTML indexing: indexable
- Ranking lane: BenchAlign v5

## Quick Verdict

No benchmark verdict yet: there is no shared sourced benchmark row for Mercury 2.5 and o3.

## Summary

- Mercury 2.5 and o3 do not currently share a sourced benchmark row. The mirror therefore compares metadata, pricing, context windows, and each model's separately reported coverage without naming a benchmark winner.

## Model Snapshot

| Property | Mercury 2.5 | o3 |
|----------|----------|----------|
| Creator | Inception | OpenAI |
| Type | Proprietary | Proprietary |
| Reasoning | Reasoning | Reasoning |
| Context | 260K | 200K |
| Independent public score (not head-to-head) | null | 47.57 |
| Benchmarks Covered | 5 | 2 |
| Pricing (input/output) | $0.04 / $0.15 | $2.00 / $8.00 |

## Category Breakdown

### Agentic

- Winner: Insufficient shared evidence
- Mercury 2.5 public-lane score: 44.5 (Estimated · #91/152)
- o3 public-lane score: Coming soon

| Benchmark | Mercury 2.5 | o3 | Winner |
|-----------|-----------|-----------|--------|
| τ³-bench results | 96.0% | Coming soon | Coming soon |
| DeepSearchQA | 34.0% | Coming soon | Coming soon |

### Coding

- Winner: Insufficient shared evidence
- Mercury 2.5 public-lane score: 47.8 (Estimated · #73/151)
- o3 public-lane score: Coming soon

| Benchmark | Mercury 2.5 | o3 | Winner |
|-----------|-----------|-----------|--------|
| SciCode | 38% | Coming soon | Coming soon |

### Multimodal & Grounded

- Winner: Insufficient shared evidence
- Mercury 2.5 public-lane score: Coming soon
- o3 public-lane score: 63.3 (Unranked · 1 rankable row)

### Reasoning

- Winner: Insufficient shared evidence
- Mercury 2.5 public-lane score: 67.7 (Unranked · 1 rankable row)
- o3 public-lane score: 72.3 (Unranked · 2 rankable rows)

### Knowledge

- Winner: Insufficient shared evidence
- Mercury 2.5 public-lane score: 48.3 (Estimated · #94/182)
- o3 public-lane score: 49.1 (Estimated · #88/182)

| Benchmark | Mercury 2.5 | o3 | Winner |
|-----------|-----------|-----------|--------|
| GPQA-D | 79.0% | Coming soon | Coming soon |

### Instruction Following

- Winner: Insufficient shared evidence
- Mercury 2.5 public-lane score: 80.1 (#53/121)
- o3 public-lane score: 87.4 (#33/121)

| Benchmark | Mercury 2.5 | o3 | Winner |
|-----------|-----------|-----------|--------|
| IFBench | 77% | Coming soon | Coming soon |

### Mathematics

- Winner: Insufficient shared evidence
- Mercury 2.5 public-lane score: Coming soon
- o3 public-lane score: 37.8 (Unranked · 2 rankable rows)

| Benchmark | Mercury 2.5 | o3 | Winner |
|-----------|-----------|-----------|--------|
| FrontierMath v2 (Tiers 1-3) | Coming soon | 18.685% | Coming soon |
| FrontierMath v2 (Tier 4) | Coming soon | 2.083% | Coming soon |

## FAQ

### Can I compare Mercury 2.5 and o3 on BenchLM yet?

Not fully yet. BenchLM is tracking both models, but sourced benchmark coverage is still incomplete for a fair score-level comparison.

### Why does this page show "coming soon" values?

BenchLM only calls winners when public benchmark coverage is available on both sides of the comparison.

## Related Comparisons

- [Mercury 2.5 vs Mercury 2.5 Preview](/compare/mercury-2-5-vs-mercury-2-5-preview)
- [o3 vs Mercury 2.5 Preview](/compare/mercury-2-5-preview-vs-o3)
- [Mercury 2.5 vs o3-pro](/compare/mercury-2-5-vs-o3-pro)
- [o3 vs o3-pro](/compare/o3-vs-o3-pro)

## Explore More

- [Mercury 2.5 profile](/models/mercury-2-5)
- [o3 profile](/models/o3)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)