Model comparison
Claude 3.5 Sonnet vs Step 3
Step 3 is the stronger model overall, scoring 39.9 to 34.4 on the Noometry Index.
Last verified . 16 shared benchmarks.
StepFunSummary
- They share 16 benchmarks with published results for both. Claude 3.5 Sonnet scores higher in 0 categories and Step 3 in 9 categories; 7 gaps are clear of the uncertainty.
- The widest gap is in math, where Step 3 leads 34.9 to 18.0.
- Step 3 has downloadable open weights; the other is API-only.
Side by side
| Claude 3.5 Sonnet | Step 3 | |
|---|---|---|
| Provider | Anthropic | StepFun |
| Noometry Index | 34.4 | 39.9 |
| Released | 2024-06-20 | — |
| Weights | Proprietary | Open |
| Context window | — | — |
| Max output | — | — |
| Input $ / M tokens | — | — |
| Output $ / M tokens | — | — |
| Results tracked | 60 | 17 |
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Category by category
Coding Too close to call
Claude 3.5 Sonnet: 39.5 (#145), Step 3: 39.5 (#144)
| Benchmark | Claude 3.5 Sonnet | Step 3 |
|---|---|---|
| LMArena Coding | 1343 | 1367 |
| Aider Polyglot | 51.6% | — |
| GSO | 4.6% | — |
| WeirdML | 40% | — |
| BigCodeBench Instruct | 46.8% | — |
| LiveBench Coding | 67.1% | — |
| BigCodeBench Complete | 58.6% | — |
| CadEval | 48% | — |
| HumanEval+ | 81.7% | — |
| MBPP+ | 74.3% | — |
Agentic & Tool Use Not comparable
Claude 3.5 Sonnet: 32.1 (#61), Step 3: —
| Benchmark | Claude 3.5 Sonnet | Step 3 |
|---|---|---|
| TheAgentCompany | 24% | — |
| Cybench | 17.5% | — |
| BALROG | 32.6% | — |
| METR Time Horizons | 45.2% | — |
Reasoning Step 3 leads
Claude 3.5 Sonnet: 22.5 (#176), Step 3: 27.6 (#102)
| Benchmark | Claude 3.5 Sonnet | Step 3 |
|---|---|---|
| LMArena Hard Prompts | 1305 | 1355 |
| SimpleBench | 41.4% | — |
| Kagi LLM Benchmark | — | 62.3% |
| EnigmaEval | 0.9% | — |
| LiveBench Reasoning | 56.7% | — |
| DTBench | 67.8% | — |
| LiveBench Data Analysis | 55% | — |
| Epoch Capabilities Index | 133.55 | — |
| ForecastBench | 60.7 | — |
| LiveBench | 59% | — |
Math Step 3 leads
Claude 3.5 Sonnet: 18.0 (#282), Step 3: 34.9 (#148)
| Benchmark | Claude 3.5 Sonnet | Step 3 |
|---|---|---|
| LMArena Math | 1306 | 1366 |
| OTIS Mock AIME 2024-2025 | 8.5% | — |
| Omni-MATH | 27.6% | — |
| LiveBench Math | 52.3% | — |
| MATH Level 5 | 56.9% | — |
| FrontierMath (Feb 2025 set) | 2.1% | — |
| FrontierMath Tier 4 (v1) | 0% | — |
Knowledge Step 3 leads
Claude 3.5 Sonnet: 28.5 (#236), Step 3: 36.2 (#161)
| Benchmark | Claude 3.5 Sonnet | Step 3 |
|---|---|---|
| LMArena Expert | 1264 | 1333 |
| GPQA Diamond | 55.3% | — |
| Humanity's Last Exam | 4.1% | — |
| MMLU-Pro | 77.7% | — |
| Confabulations | 19.9% | — |
| GPQA (HELM) | 56.5% | — |
| MMLU | 87.3% | — |
Multimodal Step 3 leads
Claude 3.5 Sonnet: 26.0 (#115), Step 3: 34.9 (#81)
| Benchmark | Claude 3.5 Sonnet | Step 3 |
|---|---|---|
| LMArena Vision | 1125 | 1176 |
| Video-MME | 60% | — |
| GeoBench | 62% | — |
| VPCT | 33% | — |
Multilingual Step 3 leads
Claude 3.5 Sonnet: 43.4 (#180), Step 3: 46.5 (#154)
| Benchmark | Claude 3.5 Sonnet | Step 3 |
|---|---|---|
| LMArena Non-English | 1283 | 1327 |
| LMArena Chinese | 1271 | 1396 |
| LMArena German | 1297 | 1371 |
| LMArena Korean | 1200 | 1271 |
| LMArena Russian | 1305 | 1331 |
| LMArena Spanish | 1289 | 1372 |
| LMArena French | 1304 | — |
| LMArena Japanese | 1234 | — |
Instruction Following Step 3 leads
Claude 3.5 Sonnet: 69.0 (#177), Step 3: 70.6 (#159)
| Benchmark | Claude 3.5 Sonnet | Step 3 |
|---|---|---|
| LMArena Instruction Following | 1297 | 1332 |
| LiveBench Instruction Following | 69.3% | — |
| IFEval | 85.5% | — |
Long Context Too close to call
Claude 3.5 Sonnet: 39.9 (#162), Step 3: 40.3 (#152)
| Benchmark | Claude 3.5 Sonnet | Step 3 |
|---|---|---|
| LMArena Longer Query | 1311 | 1326 |
Writing & Preference Step 3 leads
Claude 3.5 Sonnet: 53.0 (#159), Step 3: 54.5 (#146)
| Benchmark | Claude 3.5 Sonnet | Step 3 |
|---|---|---|
| LMArena Text | 1298 | 1351 |
| LMArena Creative Writing | 1292 | 1322 |
| LMArena Multi-Turn | 1326 | 1340 |
| Short-Story Creative Writing | 80.3% | — |
| EQ-Bench Creative Writing | 1451 | — |
| WildBench | 79.2% | — |
| LiveBench Language | 53.8% | — |
Frequently asked questions
Is Claude 3.5 Sonnet better than Step 3?
Step 3 is the stronger model overall, scoring 39.9 to 34.4 on the Noometry Index.
Is Claude 3.5 Sonnet or Step 3 better for coding?
They score almost the same on coding (39.5 vs 39.5); test both on your own repository before choosing.
How many benchmarks do Claude 3.5 Sonnet and Step 3 share?
16 benchmarks have published results for both models. Claude 3.5 Sonnet has 60 scored results on Noometry and Step 3 has 17.