Model comparison
GPT-5-Codex vs Step 2 16k Exp 202412
Step 2 16k Exp 202412 is the stronger model overall, scoring 38.6 to 37.3 on the Noometry Index.
Last verified . 0 shared benchmarks.
StepFunSummary
- The widest gap is in reasoning, where GPT-5-Codex leads 30.0 to 24.8.
Side by side
| GPT-5-Codex | Step 2 16k Exp 202412 | |
|---|---|---|
| Provider | OpenAI | StepFun |
| Noometry Index | 37.3 | 38.6 |
| Released | 2025-09-15 | — |
| Weights | Proprietary | Proprietary |
| Context window | 400K | — |
| Max output | 128K | — |
| Input $ / M tokens | $1.25 | — |
| Output $ / M tokens | $10 | — |
| Results tracked | 3 | 12 |
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Category by category
Coding GPT-5-Codex leads
GPT-5-Codex: 41.9 (#100), Step 2 16k Exp 202412: 37.9 (#170)
| Benchmark | GPT-5-Codex | Step 2 16k Exp 202412 |
|---|---|---|
| WeirdML | 54.5% | — |
| LMArena Coding | — | 1316 |
Agentic & Tool Use Not comparable
GPT-5-Codex: 30.8 (#66), Step 2 16k Exp 202412: —
| Benchmark | GPT-5-Codex | Step 2 16k Exp 202412 |
|---|---|---|
| Terminal-Bench | 44.3% | — |
Reasoning GPT-5-Codex leads
GPT-5-Codex: 30.0 (#80), Step 2 16k Exp 202412: 24.8 (#140)
| Benchmark | GPT-5-Codex | Step 2 16k Exp 202412 |
|---|---|---|
| Kagi LLM Benchmark | 70.3% | — |
| LMArena Hard Prompts | — | 1299 |
Math Not comparable
GPT-5-Codex: —, Step 2 16k Exp 202412: 33.6 (#171)
| Benchmark | GPT-5-Codex | Step 2 16k Exp 202412 |
|---|---|---|
| LMArena Math | — | 1305 |
Knowledge Not comparable
GPT-5-Codex: —, Step 2 16k Exp 202412: 34.6 (#187)
| Benchmark | GPT-5-Codex | Step 2 16k Exp 202412 |
|---|---|---|
| LMArena Expert | — | 1279 |
Multilingual Not comparable
GPT-5-Codex: —, Step 2 16k Exp 202412: 43.9 (#176)
| Benchmark | GPT-5-Codex | Step 2 16k Exp 202412 |
|---|---|---|
| LMArena Non-English | — | 1290 |
| LMArena Chinese | — | 1331 |
| LMArena Russian | — | 1324 |
Instruction Following Not comparable
GPT-5-Codex: —, Step 2 16k Exp 202412: 68.1 (#187)
| Benchmark | GPT-5-Codex | Step 2 16k Exp 202412 |
|---|---|---|
| LMArena Instruction Following | — | 1287 |
Long Context Not comparable
GPT-5-Codex: —, Step 2 16k Exp 202412: 39.7 (#165)
| Benchmark | GPT-5-Codex | Step 2 16k Exp 202412 |
|---|---|---|
| LMArena Longer Query | — | 1307 |
Writing & Preference Not comparable
GPT-5-Codex: —, Step 2 16k Exp 202412: 52.5 (#168)
| Benchmark | GPT-5-Codex | Step 2 16k Exp 202412 |
|---|---|---|
| LMArena Text | — | 1321 |
| LMArena Creative Writing | — | 1328 |
| LMArena Multi-Turn | — | 1292 |
Frequently asked questions
Is GPT-5-Codex better than Step 2 16k Exp 202412?
Step 2 16k Exp 202412 is the stronger model overall, scoring 38.6 to 37.3 on the Noometry Index.
Is GPT-5-Codex or Step 2 16k Exp 202412 better for coding?
GPT-5-Codex scores higher on coding benchmarks: 41.9 versus 37.9 in the Noometry coding category.
How many benchmarks do GPT-5-Codex and Step 2 16k Exp 202412 share?
0 benchmarks have published results for both models. GPT-5-Codex has 3 scored results on Noometry and Step 2 16k Exp 202412 has 12.