Model comparison
GPT-5 Mini vs Step 3
GPT-5 Mini is the stronger model overall, scoring 41.7 to 39.9 on the Noometry Index.
Last verified . 17 shared benchmarks.
StepFunSummary
- They share 17 benchmarks with published results for both. GPT-5 Mini scores higher in 8 categories and Step 3 in 1 category; 6 gaps are clear of the uncertainty.
- The widest gap is in math, where GPT-5 Mini leads 46.3 to 34.9.
- The biggest single-benchmark swing is Kagi LLM Benchmark: 70.3% for GPT-5 Mini and 62.3% for Step 3.
- Step 3 has downloadable open weights; the other is API-only.
Side by side
| GPT-5 Mini | Step 3 | |
|---|---|---|
| Provider | OpenAI | StepFun |
| Noometry Index | 41.7 | 39.9 |
| Released | 2025-08-07 | — |
| Weights | Proprietary | Open |
| Context window | 400K | — |
| Max output | 128K | — |
| Input $ / M tokens | $0.25 | — |
| Output $ / M tokens | $2 | — |
| Results tracked | 60 | 17 |
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Category by category
Coding Too close to call
GPT-5 Mini: 40.0 (#134), Step 3: 39.5 (#144)
| Benchmark | GPT-5 Mini | Step 3 |
|---|---|---|
| LMArena Coding | 1406 | 1367 |
| SWE-bench Verified | 64.7% | — |
| SWE-bench Verified (bash only) | 59.8% | — |
| SWE-bench Multilingual | 39.7% | — |
| SciCode | 39.2% | — |
| WeirdML | 52.7% | — |
| ALE-Bench | 799.77 | — |
| AlgoTune | 1.38 | — |
Agentic & Tool Use Not comparable
GPT-5 Mini: 31.0 (#64), Step 3: —
| Benchmark | GPT-5 Mini | Step 3 |
|---|---|---|
| Terminal-Bench | 34.8% | — |
| Berkeley Function Calling Leaderboard | 55.5% | — |
| Vending-Bench 2 | -31.18 | — |
Reasoning Step 3 leads
GPT-5 Mini: 24.1 (#153), Step 3: 27.6 (#102)
| Benchmark | GPT-5 Mini | Step 3 |
|---|---|---|
| Kagi LLM Benchmark | 70.3% | 62.3% |
| LMArena Hard Prompts | 1380 | 1355 |
| ARC-AGI-2 | 4.4% | — |
| ARC-AGI-1 | 54.3% | — |
| CritPt | 0% | — |
| Chess Puzzles | 30% | — |
| EnigmaEval | 8.2% | — |
| Mystery Game Puzzles | 10% | — |
| DTBench | 80.5% | — |
| LMCA | 34.2% | — |
| Epoch Capabilities Index | 145.51 | — |
| ForecastBench | 61 | — |
Math GPT-5 Mini leads
GPT-5 Mini: 46.3 (#59), Step 3: 34.9 (#148)
| Benchmark | GPT-5 Mini | Step 3 |
|---|---|---|
| LMArena Math | 1377 | 1366 |
| FrontierMath (Tiers 1-3) | 46.7% | — |
| FrontierMath Tier 4 | 12.2% | — |
| OTIS Mock AIME 2024-2025 | 86.7% | — |
| ProofBench | 9% | — |
| Omni-MATH | 72.2% | — |
| MATH Level 5 | 97.8% | — |
| FrontierMath (Feb 2025 set) | 27.2% | — |
| FrontierMath Tier 4 (v1) | 6.3% | — |
Knowledge GPT-5 Mini leads
GPT-5 Mini: 45.5 (#80), Step 3: 36.2 (#161)
| Benchmark | GPT-5 Mini | Step 3 |
|---|---|---|
| LMArena Expert | 1377 | 1333 |
| GPQA Diamond | 75% | — |
| Humanity's Last Exam | 19.4% | — |
| SimpleQA Verified | 21.6% | — |
| MMLU-Pro | 83.5% | — |
| Confabulations | 13.3% | — |
| Vectara Hallucination Rate | 12.9% | — |
| GPQA (HELM) | 75.6% | — |
Multimodal Too close to call
GPT-5 Mini: 35.0 (#80), Step 3: 34.9 (#81)
| Benchmark | GPT-5 Mini | Step 3 |
|---|---|---|
| LMArena Vision | 1202 | 1176 |
| VPCT | 40.2% | — |
Multilingual GPT-5 Mini leads
GPT-5 Mini: 49.1 (#131), Step 3: 46.5 (#154)
| Benchmark | GPT-5 Mini | Step 3 |
|---|---|---|
| LMArena Non-English | 1363 | 1327 |
| LMArena Chinese | 1387 | 1396 |
| LMArena German | 1366 | 1371 |
| LMArena Korean | 1306 | 1271 |
| LMArena Russian | 1362 | 1331 |
| LMArena Spanish | 1355 | 1372 |
| LMArena French | 1385 | — |
| LMArena Japanese | 1342 | — |
Instruction Following GPT-5 Mini leads
GPT-5 Mini: 76.4 (#43), Step 3: 70.6 (#159)
| Benchmark | GPT-5 Mini | Step 3 |
|---|---|---|
| LMArena Instruction Following | 1357 | 1332 |
| IFEval | 92.7% | — |
Long Context GPT-5 Mini leads
GPT-5 Mini: 41.9 (#127), Step 3: 40.3 (#152)
| Benchmark | GPT-5 Mini | Step 3 |
|---|---|---|
| LMArena Longer Query | 1355 | 1326 |
| Fiction.LiveBench | 69.4% | — |
Writing & Preference Too close to call
GPT-5 Mini: 55.4 (#143), Step 3: 54.5 (#146)
| Benchmark | GPT-5 Mini | Step 3 |
|---|---|---|
| LMArena Text | 1373 | 1351 |
| LMArena Creative Writing | 1325 | 1322 |
| LMArena Multi-Turn | 1363 | 1340 |
| Short-Story Creative Writing | 83.1% | — |
| EQ-Bench Creative Writing | 1313 | — |
| WildBench | 85.5% | — |
Frequently asked questions
Is GPT-5 Mini better than Step 3?
GPT-5 Mini is the stronger model overall, scoring 41.7 to 39.9 on the Noometry Index.
Is GPT-5 Mini or Step 3 better for coding?
They score almost the same on coding (40.0 vs 39.5); test both on your own repository before choosing.
How many benchmarks do GPT-5 Mini and Step 3 share?
17 benchmarks have published results for both models. GPT-5 Mini has 60 scored results on Noometry and Step 3 has 17.