Model comparison
GPT-5.1-Codex vs Step 2 16k Exp 202412
GPT-5.1-Codex and Step 2 16k Exp 202412 score almost the same on the Noometry Index (38.6 vs 39.2), so choose on price, context window or the category you care about most.
Last verified . 0 shared benchmarks.
StepFunSummary
- The widest gap is in math, where Step 2 16k Exp 202412 leads 36.3 to 30.3.
Side by side
| GPT-5.1-Codex | Step 2 16k Exp 202412 | |
|---|---|---|
| Provider | OpenAI | StepFun |
| Noometry Index | 38.6 | 39.2 |
| Released | 2025-11-12 | — |
| Weights | Proprietary | Proprietary |
| Context window | 400K | — |
| Max output | 128K | — |
| Input $ / M tokens | $1.25 | — |
| Output $ / M tokens | $10 | — |
| Results tracked | 6 | 12 |
Sponsored placements are available on pages like this one. Advertise on Noometry
Category by category
Coding GPT-5.1-Codex leads
GPT-5.1-Codex: 41.9 (#116), Step 2 16k Exp 202412: 38.5 (#174)
| Benchmark | GPT-5.1-Codex | Step 2 16k Exp 202412 |
|---|---|---|
| SWE-bench Verified (bash only) | 66% | — |
| LMArena WebDev | 1337 | — |
| LMArena Coding | — | 1316 |
| ALE-Bench | 1,245 | — |
Agentic & Tool Use Not comparable
GPT-5.1-Codex: 38.0 (#33), Step 2 16k Exp 202412: —
| Benchmark | GPT-5.1-Codex | Step 2 16k Exp 202412 |
|---|---|---|
| Terminal-Bench | 60.4% | — |
| METR Time Horizons | 70.8% | — |
Reasoning Not comparable
GPT-5.1-Codex: —, Step 2 16k Exp 202412: 25.9 (#142)
| Benchmark | GPT-5.1-Codex | Step 2 16k Exp 202412 |
|---|---|---|
| LMArena Hard Prompts | — | 1299 |
Math Step 2 16k Exp 202412 leads
GPT-5.1-Codex: 30.3 (#235), Step 2 16k Exp 202412: 36.3 (#169)
| Benchmark | GPT-5.1-Codex | Step 2 16k Exp 202412 |
|---|---|---|
| ProofBench | 9% | — |
| LMArena Math | — | 1304 |
Knowledge Not comparable
GPT-5.1-Codex: —, Step 2 16k Exp 202412: 35.2 (#187)
| Benchmark | GPT-5.1-Codex | Step 2 16k Exp 202412 |
|---|---|---|
| LMArena Expert | — | 1279 |
Multilingual Not comparable
GPT-5.1-Codex: —, Step 2 16k Exp 202412: 43.7 (#181)
| Benchmark | GPT-5.1-Codex | Step 2 16k Exp 202412 |
|---|---|---|
| LMArena Non-English | — | 1290 |
| LMArena Chinese | — | 1331 |
| LMArena Russian | — | 1324 |
Instruction Following Not comparable
GPT-5.1-Codex: —, Step 2 16k Exp 202412: 67.9 (#192)
| Benchmark | GPT-5.1-Codex | Step 2 16k Exp 202412 |
|---|---|---|
| LMArena Instruction Following | — | 1287 |
Long Context Not comparable
GPT-5.1-Codex: —, Step 2 16k Exp 202412: 39.7 (#170)
| Benchmark | GPT-5.1-Codex | Step 2 16k Exp 202412 |
|---|---|---|
| LMArena Longer Query | — | 1307 |
Writing & Preference Not comparable
GPT-5.1-Codex: —, Step 2 16k Exp 202412: 52.3 (#173)
| Benchmark | GPT-5.1-Codex | Step 2 16k Exp 202412 |
|---|---|---|
| LMArena Text | — | 1321 |
| LMArena Creative Writing | — | 1328 |
| LMArena Multi-Turn | — | 1292 |
Frequently asked questions
Is GPT-5.1-Codex better than Step 2 16k Exp 202412?
GPT-5.1-Codex and Step 2 16k Exp 202412 score almost the same on the Noometry Index (38.6 vs 39.2), so choose on price, context window or the category you care about most.
Is GPT-5.1-Codex or Step 2 16k Exp 202412 better for coding?
GPT-5.1-Codex scores higher on coding benchmarks: 41.9 versus 38.5 in the Noometry coding category.
How many benchmarks do GPT-5.1-Codex and Step 2 16k Exp 202412 share?
0 benchmarks have published results for both models. GPT-5.1-Codex has 6 scored results on Noometry and Step 2 16k Exp 202412 has 12.