# GPT-5 Nano vs Solar Pro4

> Solar Pro4 is the stronger model overall, scoring 41.5 to 33.4 on the Noometry Index. GPT-5 Nano costs 3.8× less per token, which makes it the better buy when Solar Pro4's lead doesn't matter for your workload.

- Canonical page: https://noometry.com/compare/gpt-5-nano-vs-solar-pro4
- Last updated: 2026-10-10
- Shared benchmarks: 15

## Summary

- They share 15 benchmarks with published results for both. GPT-5 Nano scores higher in 1 category and Solar Pro4 in 7 categories; 8 gaps are clear of the uncertainty.
- The widest gap is in writing & preference, where Solar Pro4 leads 56.7 to 39.4.
- GPT-5 Nano is cheaper at $0.05 / $0.40 per million input/output tokens, against $0.30 / $1.20 for Solar Pro4.
- Solar Pro4 accepts more context: 524K tokens versus 400K.

## Snapshot

| | GPT-5 Nano | Solar Pro4 |
|---|---|---|
| Provider | OpenAI | Upstage |
| Noometry Index | 33.4 | 41.5 |
| Rank | 234 | 123 |
| Context | 400K | 524K |
| Input $/M | $0.05 | $0.30 |
| Output $/M | $0.40 | $1.20 |
| Weights | Proprietary | Proprietary |

## Coding

- GPT-5 Nano: 33.3 (#248)
- Solar Pro4: 39.9 (#135)

| Benchmark | GPT-5 Nano | Solar Pro4 |
|---|---|---|
| LMArena Coding | 1351 | 1439 |
| SWE-bench Verified (bash only) | 34.8% | — |
| LMArena WebDev | — | 1371 |
| WeirdML | 38.1% | — |
| ALE-Bench | 718.67 | — |

## Agentic & Tool Use

- GPT-5 Nano: 25.6 (#99)
- Solar Pro4: —

| Benchmark | GPT-5 Nano | Solar Pro4 |
|---|---|---|
| Terminal-Bench | 21.8% | — |
| Berkeley Function Calling Leaderboard | 51.5% | — |

## Reasoning

- GPT-5 Nano: 16.4 (#291)
- Solar Pro4: 27.3 (#107)

| Benchmark | GPT-5 Nano | Solar Pro4 |
|---|---|---|
| LMArena Hard Prompts | 1329 | 1398 |
| ARC-AGI-2 | 2.6% | — |
| Kagi LLM Benchmark | 62.2% | — |
| ARC-AGI-1 | 20.7% | — |
| Chess Puzzles | 27% | — |
| Mystery Game Puzzles | 9% | — |
| DTBench | 62.7% | — |
| LMCA | 7.9% | — |
| Epoch Capabilities Index | 139.39 | — |
| ForecastBench | 59.1 | — |

## Math

- GPT-5 Nano: 29.1 (#221)
- Solar Pro4: 36.1 (#129)

| Benchmark | GPT-5 Nano | Solar Pro4 |
|---|---|---|
| LMArena Math | 1318 | 1418 |
| FrontierMath (Tiers 1-3) | 20% | — |
| FrontierMath Tier 4 | 2.4% | — |
| OTIS Mock AIME 2024-2025 | 81.1% | — |
| ProofBench | 12% | — |
| Omni-MATH | 54.6% | — |
| MATH Level 5 | 95.2% | — |
| FrontierMath (Feb 2025 set) | 8.3% | — |
| FrontierMath Tier 4 (v1) | 2.1% | — |

## Knowledge

- GPT-5 Nano: 35.8 (#166)
- Solar Pro4: 39.0 (#128)

| Benchmark | GPT-5 Nano | Solar Pro4 |
|---|---|---|
| LMArena Expert | 1321 | 1421 |
| GPQA Diamond | 69.4% | — |
| SimpleQA Verified | 11.7% | — |
| MMLU-Pro | 77.8% | — |
| Vectara Hallucination Rate | 10.5% | — |
| GPQA (HELM) | 67.9% | — |

## Multimodal

- GPT-5 Nano: 30.7 (#102)
- Solar Pro4: —

| Benchmark | GPT-5 Nano | Solar Pro4 |
|---|---|---|
| LMArena Vision | 1159 | — |
| VPCT | 37.2% | — |

## Multilingual

- GPT-5 Nano: 45.5 (#167)
- Solar Pro4: 49.0 (#134)

| Benchmark | GPT-5 Nano | Solar Pro4 |
|---|---|---|
| LMArena Non-English | 1313 | 1362 |
| LMArena Chinese | 1355 | 1417 |
| LMArena German | 1329 | 1351 |
| LMArena Korean | 1269 | 1383 |
| LMArena Russian | 1296 | 1360 |
| LMArena Spanish | 1360 | 1408 |
| LMArena French | — | 1403 |
| LMArena Japanese | — | 1300 |

## Instruction Following

- GPT-5 Nano: 75.2 (#72)
- Solar Pro4: 72.8 (#128)

| Benchmark | GPT-5 Nano | Solar Pro4 |
|---|---|---|
| LMArena Instruction Following | 1306 | 1376 |
| IFEval | 93.2% | — |

## Long Context

- GPT-5 Nano: 31.3 (#275)
- Solar Pro4: 42.0 (#125)

| Benchmark | GPT-5 Nano | Solar Pro4 |
|---|---|---|
| LMArena Longer Query | 1313 | 1379 |
| Fiction.LiveBench | 44.4% | — |

## Writing & Preference

- GPT-5 Nano: 39.4 (#244)
- Solar Pro4: 56.7 (#133)

| Benchmark | GPT-5 Nano | Solar Pro4 |
|---|---|---|
| LMArena Text | 1320 | 1386 |
| LMArena Creative Writing | 1250 | 1313 |
| LMArena Multi-Turn | 1311 | 1391 |
| EQ-Bench Creative Writing | 705 | — |
| WildBench | 80.6% | — |

## FAQ

### Is GPT-5 Nano better than Solar Pro4?

Solar Pro4 is the stronger model overall, scoring 41.5 to 33.4 on the Noometry Index. GPT-5 Nano costs 3.8× less per token, which makes it the better buy when Solar Pro4's lead doesn't matter for your workload.

### Which is cheaper, GPT-5 Nano or Solar Pro4?

GPT-5 Nano is cheaper. It lists at $0.05 per million input tokens and $0.40 per million output tokens; Solar Pro4 lists at $0.30 and $1.20.

### Is GPT-5 Nano or Solar Pro4 better for coding?

Solar Pro4 scores higher on coding benchmarks: 39.9 versus 33.3 in the Noometry coding category.

### Which has the bigger context window?

Solar Pro4 does, with 524K tokens against 400K.

### How many benchmarks do GPT-5 Nano and Solar Pro4 share?

15 benchmarks have published results for both models. GPT-5 Nano has 48 scored results on Noometry and Solar Pro4 has 18.