Model comparison
Grok 4.3 vs Step 3
Grok 4.3 is the stronger model overall, scoring 43.8 to 40.5 on the Noometry Index.
Last verified . 16 shared benchmarks.
StepFunSummary
- They share 16 benchmarks with published results for both. Grok 4.3 scores higher in 8 categories and Step 3 in 1 category; 9 gaps are clear of the uncertainty.
- The widest gap is in knowledge, where Grok 4.3 leads 52.5 to 36.8.
- Step 3 has downloadable open weights; the other is API-only.
Side by side
| Grok 4.3 | Step 3 | |
|---|---|---|
| Provider | xAI | StepFun |
| Noometry Index | 43.8 | 40.5 |
| Released | 2026-04-17 | — |
| Weights | Proprietary | Open |
| Context window | 1M | — |
| Max output | 30K | — |
| Input $ / M tokens | $1.25 | — |
| Output $ / M tokens | $2.50 | — |
| Results tracked | 40 | 17 |
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Category by category
Coding Grok 4.3 leads
Grok 4.3: 41.6 (#121), Step 3: 40.1 (#147)
| Benchmark | Grok 4.3 | Step 3 |
|---|---|---|
| LMArena Coding | 1415 | 1367 |
| LMArena WebDev | 1357 | — |
| SciCode | 47.3% | — |
| WeirdML | 49.9% | — |
| ALE-Bench | 944.17 | — |
Agentic & Tool Use Not comparable
Grok 4.3: 27.7 (#99), Step 3: —
| Benchmark | Grok 4.3 | Step 3 |
|---|---|---|
| GDP.pdf | 8% | — |
| LMArena Search | 1165 | — |
| Vending-Bench 2 | 35.26 | — |
Reasoning Grok 4.3 leads
Grok 4.3: 35.9 (#68), Step 3: 28.4 (#105)
| Benchmark | Grok 4.3 | Step 3 |
|---|---|---|
| LMArena Hard Prompts | 1396 | 1355 |
| Kagi LLM Benchmark | — | 62.3% |
| NYT Connections (extended) | 55.2% | — |
| CritPt | 8% | — |
| Chess Puzzles | 25% | — |
| DTBench | 90.7% | — |
| LMCA | 38.3% | — |
| Epoch Capabilities Index | 149.16 | — |
| ForecastBench | 60.3 | — |
Math Grok 4.3 leads
Grok 4.3: 46.0 (#74), Step 3: 37.6 (#148)
| Benchmark | Grok 4.3 | Step 3 |
|---|---|---|
| LMArena Math | 1388 | 1366 |
| FrontierMath (Tiers 1-3) | 42.8% | — |
| FrontierMath Tier 4 | 14.6% | — |
| OTIS Mock AIME 2024-2025 | 93.3% | — |
| ProofBench | 11% | — |
Knowledge Grok 4.3 leads
Grok 4.3: 52.5 (#62), Step 3: 36.8 (#164)
| Benchmark | Grok 4.3 | Step 3 |
|---|---|---|
| LMArena Expert | 1385 | 1333 |
| GPQA Diamond | 88.8% | — |
| SimpleQA Verified | 33.2% | — |
Multimodal Step 3 leads
Grok 4.3: 31.6 (#104), Step 3: 35.5 (#86)
| Benchmark | Grok 4.3 | Step 3 |
|---|---|---|
| LMArena Vision | 1229 | 1177 |
| Blueprint-Bench 2 | 0% | — |
Multilingual Grok 4.3 leads
Grok 4.3: 50.5 (#120), Step 3: 46.3 (#159)
| Benchmark | Grok 4.3 | Step 3 |
|---|---|---|
| LMArena Non-English | 1385 | 1327 |
| LMArena Chinese | 1422 | 1397 |
| LMArena German | 1395 | 1371 |
| LMArena Korean | 1356 | 1269 |
| LMArena Russian | 1399 | 1331 |
| LMArena Spanish | 1398 | 1371 |
| LMArena French | 1412 | — |
| LMArena Japanese | 1379 | — |
Instruction Following Grok 4.3 leads
Grok 4.3: 72.1 (#140), Step 3: 70.4 (#164)
| Benchmark | Grok 4.3 | Step 3 |
|---|---|---|
| LMArena Instruction Following | 1366 | 1332 |
Long Context Grok 4.3 leads
Grok 4.3: 42.5 (#123), Step 3: 40.3 (#157)
| Benchmark | Grok 4.3 | Step 3 |
|---|---|---|
| LMArena Longer Query | 1393 | 1326 |
Writing & Preference Grok 4.3 leads
Grok 4.3: 58.5 (#118), Step 3: 54.3 (#151)
| Benchmark | Grok 4.3 | Step 3 |
|---|---|---|
| LMArena Text | 1397 | 1350 |
| LMArena Creative Writing | 1380 | 1321 |
| LMArena Multi-Turn | 1406 | 1341 |
| EQ-Bench 4 | 1075 | — |
Frequently asked questions
Is Grok 4.3 better than Step 3?
Grok 4.3 is the stronger model overall, scoring 43.8 to 40.5 on the Noometry Index.
Is Grok 4.3 or Step 3 better for coding?
Grok 4.3 scores higher on coding benchmarks: 41.6 versus 40.1 in the Noometry coding category.
How many benchmarks do Grok 4.3 and Step 3 share?
16 benchmarks have published results for both models. Grok 4.3 has 40 scored results on Noometry and Step 3 has 17.