Model comparison
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.
Last verified . 15 shared benchmarks.
UpstageSummary
- 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.
Side by side
| GPT-5 Nano | Solar Pro4 | |
|---|---|---|
| Provider | OpenAI | Upstage |
| Noometry Index | 33.4 | 41.5 |
| Released | 2025-08-07 | 2026-08-06 |
| Weights | Proprietary | Proprietary |
| Context window | 400K | 524K |
| Max output | 128K | 131K |
| Input $ / M tokens | $0.05 | $0.30 |
| Output $ / M tokens | $0.40 | $1.20 |
| Results tracked | 48 | 18 |
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Category by category
Coding Solar Pro4 leads
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 Not comparable
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 Solar Pro4 leads
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 Solar Pro4 leads
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 Solar Pro4 leads
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 Not comparable
GPT-5 Nano: 30.7 (#102), Solar Pro4: —
| Benchmark | GPT-5 Nano | Solar Pro4 |
|---|---|---|
| LMArena Vision | 1159 | — |
| VPCT | 37.2% | — |
Multilingual Solar Pro4 leads
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 leads
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 Solar Pro4 leads
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 Solar Pro4 leads
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% | — |
Frequently asked questions
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.