Model comparison
Claude Sonnet 4.5 vs Solar Pro4
Claude Sonnet 4.5 is the stronger model overall, scoring 44.1 to 42.1 on the Noometry Index. Solar Pro4 costs 11× less per token, which makes it the better buy when Claude Sonnet 4.5's lead doesn't matter for your workload.
Last verified . 18 shared benchmarks.
UpstageSummary
- They share 18 benchmarks with published results for both. Claude Sonnet 4.5 scores higher in 6 categories and Solar Pro4 in 2 categories; 8 gaps are clear of the uncertainty.
- The widest gap is in writing & preference, where Claude Sonnet 4.5 leads 66.5 to 56.5.
- Solar Pro4 is cheaper at $0.30 / $1.20 per million input/output tokens, against $3 / $15 for Claude Sonnet 4.5.
- Solar Pro4 accepts more context: 524K tokens versus 200K.
Side by side
| Claude Sonnet 4.5 | Solar Pro4 | |
|---|---|---|
| Provider | Anthropic | Upstage |
| Noometry Index | 44.1 | 42.1 |
| Released | 2025-09-29 | 2026-08-06 |
| Weights | Proprietary | Proprietary |
| Context window | 200K | 524K |
| Max output | 64K | 131K |
| Input $ / M tokens | $3 | $0.30 |
| Output $ / M tokens | $15 | $1.20 |
| Results tracked | 73 | 18 |
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Category by category
Coding Claude Sonnet 4.5 leads
Claude Sonnet 4.5: 47.3 (#61), Solar Pro4: 40.1 (#149)
| Benchmark | Claude Sonnet 4.5 | Solar Pro4 |
|---|---|---|
| LMArena WebDev | 1393 | 1371 |
| LMArena Coding | 1489 | 1437 |
| SWE-bench Verified | 71.3% | — |
| SWE-bench Verified (bash only) | 71.4% | — |
| SWE-bench Multilingual | 67% | — |
| SciCode | 44.7% | — |
| GSO | 14.7% | — |
| WeirdML | 47.7% | — |
| ALE-Bench | 796.15 | — |
| AlgoTune | 1.52 | — |
Agentic & Tool Use Not comparable
Claude Sonnet 4.5: 38.3 (#32), Solar Pro4: —
| Benchmark | Claude Sonnet 4.5 | Solar Pro4 |
|---|---|---|
| Terminal-Bench | 46.5% | — |
| Berkeley Function Calling Leaderboard | 73.2% | — |
| GDPval | 42.5% | — |
| Remote Labor Index | 2.1% | — |
| τ²-bench Airline | 72% | — |
| τ²-bench Banking | 25.3% | — |
| τ²-bench Retail | 72.4% | — |
| τ²-bench Telecom | 84.9% | — |
| Cybench | 60% | — |
| DeepResearch Bench | 52.6% | — |
| OSWorld | 62.9% | — |
| LMArena Search | 1159 | — |
| METR Time Horizons | 67.4% | — |
| Vending-Bench 2 | 3,839 | — |
Reasoning Solar Pro4 leads
Claude Sonnet 4.5: 26.9 (#125), Solar Pro4: 28.5 (#104)
| Benchmark | Claude Sonnet 4.5 | Solar Pro4 |
|---|---|---|
| LMArena Hard Prompts | 1462 | 1399 |
| ARC-AGI-2 | 13.6% | — |
| SimpleBench | 54.3% | — |
| Kagi LLM Benchmark | 57.9% | — |
| NYT Connections (extended) | 37.3% | — |
| ARC-AGI-1 | 63.7% | — |
| CritPt | 1.1% | — |
| Chess Puzzles | 12% | — |
| EnigmaEval | 6% | — |
| EBR-Bench | 2.4% | — |
| Mystery Game Puzzles | 17% | — |
| DTBench | 83.2% | — |
| LMCA | 38.8% | — |
| Epoch Capabilities Index | 146.84 | — |
| ForecastBench | 61.9 | — |
Math Solar Pro4 leads
Claude Sonnet 4.5: 32.3 (#216), Solar Pro4: 38.8 (#128)
| Benchmark | Claude Sonnet 4.5 | Solar Pro4 |
|---|---|---|
| LMArena Math | 1449 | 1416 |
| FrontierMath (Tiers 1-3) | 23.9% | — |
| FrontierMath Tier 4 | 2.4% | — |
| OTIS Mock AIME 2024-2025 | 77.8% | — |
| ProofBench | 19% | — |
| Omni-MATH | 55.3% | — |
| MATH Level 5 | 97.7% | — |
| FrontierMath (Feb 2025 set) | 15.2% | — |
| FrontierMath Tier 4 (v1) | 4.2% | — |
Knowledge Claude Sonnet 4.5 leads
Claude Sonnet 4.5: 48.4 (#76), Solar Pro4: 39.8 (#129)
| Benchmark | Claude Sonnet 4.5 | Solar Pro4 |
|---|---|---|
| LMArena Expert | 1482 | 1427 |
| GPQA Diamond | 82.3% | — |
| Humanity's Last Exam | 13.7% | — |
| SimpleQA Verified | 30.7% | — |
| MMLU-Pro | 86.9% | — |
| Vectara Hallucination Rate | 12% | — |
| GPQA (HELM) | 68.6% | — |
Multimodal Not comparable
Claude Sonnet 4.5: 34.8 (#89), Solar Pro4: —
| Benchmark | Claude Sonnet 4.5 | Solar Pro4 |
|---|---|---|
| VPCT | 39.8% | — |
| LMArena Document | 1450 | — |
Multilingual Claude Sonnet 4.5 leads
Claude Sonnet 4.5: 53.4 (#69), Solar Pro4: 48.7 (#139)
| Benchmark | Claude Sonnet 4.5 | Solar Pro4 |
|---|---|---|
| LMArena Non-English | 1425 | 1361 |
| LMArena Chinese | 1459 | 1415 |
| LMArena French | 1458 | 1397 |
| LMArena German | 1427 | 1364 |
| LMArena Japanese | 1390 | 1309 |
| LMArena Korean | 1403 | 1382 |
| LMArena Russian | 1437 | 1360 |
| LMArena Spanish | 1457 | 1401 |
Instruction Following Claude Sonnet 4.5 leads
Claude Sonnet 4.5: 75.0 (#78), Solar Pro4: 72.7 (#132)
| Benchmark | Claude Sonnet 4.5 | Solar Pro4 |
|---|---|---|
| LMArena Instruction Following | 1459 | 1377 |
| IFEval | 85% | — |
Long Context Claude Sonnet 4.5 leads
Claude Sonnet 4.5: 45.2 (#46), Solar Pro4: 42.1 (#130)
| Benchmark | Claude Sonnet 4.5 | Solar Pro4 |
|---|---|---|
| LMArena Longer Query | 1476 | 1381 |
Writing & Preference Claude Sonnet 4.5 leads
Claude Sonnet 4.5: 66.5 (#34), Solar Pro4: 56.5 (#138)
| Benchmark | Claude Sonnet 4.5 | Solar Pro4 |
|---|---|---|
| LMArena Text | 1439 | 1386 |
| LMArena Creative Writing | 1442 | 1316 |
| LMArena Multi-Turn | 1465 | 1385 |
| EQ-Bench Creative Writing | 1678 | — |
| WildBench | 85.4% | — |
Frequently asked questions
Is Claude Sonnet 4.5 better than Solar Pro4?
Claude Sonnet 4.5 is the stronger model overall, scoring 44.1 to 42.1 on the Noometry Index. Solar Pro4 costs 11× less per token, which makes it the better buy when Claude Sonnet 4.5's lead doesn't matter for your workload.
Which is cheaper, Claude Sonnet 4.5 or Solar Pro4?
Solar Pro4 is cheaper. It lists at $0.30 per million input tokens and $1.20 per million output tokens; Claude Sonnet 4.5 lists at $3 and $15.
Is Claude Sonnet 4.5 or Solar Pro4 better for coding?
Claude Sonnet 4.5 scores higher on coding benchmarks: 47.3 versus 40.1 in the Noometry coding category.
Which has the bigger context window?
Solar Pro4 does, with 524K tokens against 200K.
How many benchmarks do Claude Sonnet 4.5 and Solar Pro4 share?
18 benchmarks have published results for both models. Claude Sonnet 4.5 has 73 scored results on Noometry and Solar Pro4 has 18.