# GPT-5.4 nano vs Solar Open 2

> Side-by-side benchmark comparison for GPT-5.4 nano and Solar Open 2 across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/gpt-5-4-nano-vs-solar-open-2
- Last updated: September 10, 2026

- Shared sourced benchmarks: 2
- HTML indexing: indexable
- Ranking lane: BenchAlign v5

## Quick Verdict

Evidence is too thin for a benchmark verdict: GPT-5.4 nano and Solar Open 2 share only 2 sourced benchmark rows.

## Summary

- Only 2 shared sourced benchmark rows are available. That is not enough for a broad capability verdict, so this mirror does not name an overall winner.
- Solar Open 2 has the lower published output-token price.
- Solar Open 2 has the larger published context window at 1M.

## Model Snapshot

| Property | GPT-5.4 nano | Solar Open 2 |
|----------|----------|----------|
| Creator | OpenAI | Upstage |
| Type | Proprietary | Open Weight |
| Reasoning | Reasoning | Reasoning |
| Context | 400K | 1M |
| Independent public score (not head-to-head) | 59.57 | null |
| Benchmarks Covered | 18 | 11 |
| Pricing (input/output) | $0.20 / $1.25 | $0.00 / $0.00 |

## Category Breakdown

### Agentic

- Winner: Insufficient shared evidence
- GPT-5.4 nano public-lane score: 34.6 (Supported · #133/152)
- Solar Open 2 public-lane score: Coming soon

| Benchmark | GPT-5.4 nano | Solar Open 2 | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 2.0 | 46.3% | Coming soon | Coming soon |
| OSWorld-Verified | 39% | Coming soon | Coming soon |
| MCP Atlas | 56.1% | 58.2% | Solar Open 2 |
| Toolathlon | 35.5% | Coming soon | Coming soon |
| τ²-bench results | 92.5% | Coming soon | Coming soon |
| Terminal-Bench 2.1 (Vals) | 41.6% | Coming soon | Coming soon |
| terminalBenchHard | Coming soon | 28.3% | Coming soon |
| APEX-Agents | Coming soon | 16.6% | Coming soon |

### Coding

- Winner: Insufficient shared evidence
- GPT-5.4 nano public-lane score: 37.1 (Supported · #126/151)
- Solar Open 2 public-lane score: Coming soon

| Benchmark | GPT-5.4 nano | Solar Open 2 | Winner |
|-----------|-----------|-----------|--------|
| Vibe Code Bench | 26.10% | Coming soon | Coming soon |
| LiveCodeBench (Vals) | 84.0% | Coming soon | Coming soon |
| SWE-bench (Vals) | 69.8% | Coming soon | Coming soon |
| LiveCodeBench v6 | Coming soon | 92.4% | Coming soon |
| SWE-bench Verified | Coming soon | 70.4% | Coming soon |

### Multimodal & Grounded

- Winner: Insufficient shared evidence
- GPT-5.4 nano public-lane score: 23.8 (#45/48)
- Solar Open 2 public-lane score: Coming soon

| Benchmark | GPT-5.4 nano | Solar Open 2 | Winner |
|-----------|-----------|-----------|--------|
| MMMU-Pro | 66.1% | Coming soon | Coming soon |
| MMMU-Pro w/ Python | 69.5% | Coming soon | Coming soon |

### Reasoning

- Winner: Insufficient shared evidence
- GPT-5.4 nano public-lane score: 73.7 (Unranked · 2 rankable rows)
- Solar Open 2 public-lane score: Coming soon

### Knowledge

- Winner: Insufficient shared evidence
- GPT-5.4 nano public-lane score: 47.4 (Supported · #97/183)
- Solar Open 2 public-lane score: Coming soon

| Benchmark | GPT-5.4 nano | Solar Open 2 | Winner |
|-----------|-----------|-----------|--------|
| GPQA | 82.8% | Coming soon | Coming soon |
| HLE | 37.7% | Coming soon | Coming soon |
| HLE w/o tools | 24.3% | 28.8% | Solar Open 2 |
| GPQA Diamond (Vals) | 77.5% | Coming soon | Coming soon |
| MMLU-Pro (Vals) | 77.2% | Coming soon | Coming soon |
| MMLU-Pro | Coming soon | 86.2% | Coming soon |
| GPQA-D | Coming soon | 86.3% | Coming soon |

### Instruction Following

- Winner: Insufficient shared evidence
- GPT-5.4 nano public-lane score: 93.2 (#9/123)
- Solar Open 2 public-lane score: Coming soon

| Benchmark | GPT-5.4 nano | Solar Open 2 | Winner |
|-----------|-----------|-----------|--------|
| IFBench | Coming soon | 80% | Coming soon |

### Mathematics

- Winner: Insufficient shared evidence
- GPT-5.4 nano public-lane score: 43.9 (Unranked · 2 rankable rows)
- Solar Open 2 public-lane score: Coming soon

| Benchmark | GPT-5.4 nano | Solar Open 2 | Winner |
|-----------|-----------|-----------|--------|
| FrontierMath v2 (Tiers 1-3) | 25.860% | Coming soon | Coming soon |
| FrontierMath v2 (Tier 4) | 6.250% | Coming soon | Coming soon |
| HMMT Feb 2026 | Coming soon | 93.9% | Coming soon |
| AIME26 | Coming soon | 95.7% | Coming soon |

## FAQ

### Is there enough evidence to pick between GPT-5.4 nano and Solar Open 2?

Not yet. The models share only 2 sourced benchmark rows, 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

- [GPT-5.4 nano vs GPT-5.4](/compare/gpt-5-4-vs-gpt-5-4-nano)
- [Solar Open 2 vs GPT-5.4](/compare/gpt-5-4-vs-solar-open-2)
- [GPT-5.4 nano vs GPT-5.4 mini](/compare/gpt-5-4-mini-vs-gpt-5-4-nano)
- [Solar Open 2 vs GPT-5.4 mini](/compare/gpt-5-4-mini-vs-solar-open-2)

## Explore More

- [GPT-5.4 nano profile](/models/gpt-5-4-nano)
- [Solar Open 2 profile](/models/solar-open-2)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)