Model comparison
GPT-6 Astra vs Step 3
GPT-6 Astra is the stronger model overall, scoring 70.8 to 40.5 on the Noometry Index.
Last verified . 16 shared benchmarks.
StepFunSummary
- They share 16 benchmarks with published results for both. GPT-6 Astra scores higher in 9 categories and Step 3 in 0 categories; 9 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where GPT-6 Astra leads 85.1 to 28.4.
- Step 3 has downloadable open weights; the other is API-only.
Side by side
| GPT-6 Astra | Step 3 | |
|---|---|---|
| Provider | OpenAI | StepFun |
| Noometry Index | 70.8 | 40.5 |
| Released | 2026-09-03 | — |
| Weights | Proprietary | Open |
| Context window | 1.05M | — |
| Max output | 128K | — |
| Input $ / M tokens | $10 | — |
| Output $ / M tokens | $50 | — |
| Results tracked | 56 | 17 |
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Category by category
Coding GPT-6 Astra leads
GPT-6 Astra: 73.7 (#2), Step 3: 40.1 (#147)
| Benchmark | GPT-6 Astra | Step 3 |
|---|---|---|
| LMArena Coding | 1487 | 1367 |
| DeepSWE | 74.1% | — |
| FrontierCode | 53.3% | — |
| LMArena WebDev | 1786 | — |
| FrontierSWE | 65.5% | — |
| SciCode | 56.5% | — |
| GSO | 79.4% | — |
| WeirdML | 93.6% | — |
| MirrorCode | 46.7% | — |
| ALE-Bench | 2,951 | — |
Agentic & Tool Use Not comparable
GPT-6 Astra: 52.9 (#3), Step 3: —
| Benchmark | GPT-6 Astra | Step 3 |
|---|---|---|
| APEX-Agents | 64.7% | — |
| Remote Labor Index | 20.8% | — |
| BALROG | 68.3% | — |
| GDP.pdf | 34.2% | — |
| Vending-Bench 2 | 15,515 | — |
Reasoning GPT-6 Astra leads
GPT-6 Astra: 85.1 (#1), Step 3: 28.4 (#105)
| Benchmark | GPT-6 Astra | Step 3 |
|---|---|---|
| LMArena Hard Prompts | 1462 | 1355 |
| ARC-AGI-2 | 95% | — |
| Kagi LLM Benchmark | — | 62.3% |
| NYT Connections (extended) | 98.1% | — |
| ARC-AGI-1 | 98.5% | — |
| CritPt | 31.7% | — |
| Chess Puzzles | 72% | — |
| EBR-Bench | 76.2% | — |
| Mystery Game Puzzles | 84% | — |
| DTBench | 97.3% | — |
| LMCA | 64.4% | — |
| Bench to the Future 3 | 0.14 | — |
| Epoch Capabilities Index | 166.45 | — |
Math GPT-6 Astra leads
GPT-6 Astra: 93.5 (#2), Step 3: 37.6 (#148)
| Benchmark | GPT-6 Astra | Step 3 |
|---|---|---|
| LMArena Math | 1465 | 1366 |
| FrontierMath (Tiers 1-3) | 93.7% | — |
| FrontierMath Tier 4 | 97.6% | — |
| OTIS Mock AIME 2024-2025 | 100% | — |
| ProofBench | 99% | — |
| FrontierMath Erdős | 2.9% | — |
Knowledge GPT-6 Astra leads
GPT-6 Astra: 75.3 (#1), Step 3: 36.8 (#164)
| Benchmark | GPT-6 Astra | Step 3 |
|---|---|---|
| LMArena Expert | 1483 | 1333 |
| GPQA Diamond | 95.8% | — |
| Humanity's Last Exam | 54.8% | — |
| SimpleQA Verified | 75.6% | — |
| Vectara Hallucination Rate | 8.7% | — |
Multimodal GPT-6 Astra leads
GPT-6 Astra: 55.0 (#3), Step 3: 35.5 (#86)
| Benchmark | GPT-6 Astra | Step 3 |
|---|---|---|
| LMArena Vision | 1281 | 1177 |
| Blueprint-Bench 2 | 49.7% | — |
| Furniture Assembly | 80% | — |
| LMArena Document | 1468 | — |
Multilingual GPT-6 Astra leads
GPT-6 Astra: 53.7 (#61), Step 3: 46.3 (#159)
| Benchmark | GPT-6 Astra | Step 3 |
|---|---|---|
| LMArena Non-English | 1430 | 1327 |
| LMArena Chinese | 1484 | 1397 |
| LMArena German | 1440 | 1371 |
| LMArena Korean | 1426 | 1269 |
| LMArena Russian | 1436 | 1331 |
| LMArena Spanish | 1407 | 1371 |
| LMArena French | 1456 | — |
| LMArena Japanese | 1379 | — |
Instruction Following GPT-6 Astra leads
GPT-6 Astra: 76.3 (#44), Step 3: 70.4 (#164)
| Benchmark | GPT-6 Astra | Step 3 |
|---|---|---|
| LMArena Instruction Following | 1450 | 1332 |
Long Context GPT-6 Astra leads
GPT-6 Astra: 44.5 (#62), Step 3: 40.3 (#157)
| Benchmark | GPT-6 Astra | Step 3 |
|---|---|---|
| LMArena Longer Query | 1456 | 1326 |
Writing & Preference GPT-6 Astra leads
GPT-6 Astra: 75.3 (#7), Step 3: 54.3 (#151)
| Benchmark | GPT-6 Astra | Step 3 |
|---|---|---|
| LMArena Text | 1441 | 1350 |
| LMArena Creative Writing | 1418 | 1321 |
| LMArena Multi-Turn | 1448 | 1341 |
| EQ-Bench Creative Writing | 2173 | — |
Frequently asked questions
Is GPT-6 Astra better than Step 3?
GPT-6 Astra is the stronger model overall, scoring 70.8 to 40.5 on the Noometry Index.
Is GPT-6 Astra or Step 3 better for coding?
GPT-6 Astra scores higher on coding benchmarks: 73.7 versus 40.1 in the Noometry coding category.
How many benchmarks do GPT-6 Astra and Step 3 share?
16 benchmarks have published results for both models. GPT-6 Astra has 56 scored results on Noometry and Step 3 has 17.