GPT 5.5 InstantvsStep 2 16k Exp 202412
GPT 5.5 Instant leads the overall Podium Score by 7.0 points (74.0 vs 67.0).Category wins: GPT 5.5 Instant 0 — 0 Step 2 16k Exp 202412.Step 2 16k Exp 202412 is the cheaper pick ($3/M vs $10/M per 1M output tokens). GPT 5.5 Instant is faster (50 t/s vs 50 t/s).
Key VerdictAggregated 2026 Benchmark Analysis
GPT 5.5 Instant is rated higher overall with a Podium Score of 74.0 (vs 67.0 for Step 2 16k Exp 202412). Both models show closely matched capabilities across domain benchmarks.
Coding & Engineering
Comparable
Inference Speed
GPT 5.5 Instant (50 t/s)
Cost Efficiency
Step 2 16k Exp 202412 ($3/M/M)
| Metric | GPT 5.5 Instant | Step 2 16k Exp 202412 |
|---|---|---|
| Podium Score | 74.0 ▲ | 67.0 |
| Arena Elo | — | — |
| Intelligence Index | — | — |
| Coding | — | — |
| Math | — | — |
| Reasoning | — | — |
| Agentic | — | — |
| Knowledge | — | — |
| Multimodal | — | — |
| Long-context | — | — |
| Output speed | 50 t/s | 50 t/s |
| Output price | $10/M | $3/M ▲ |
| Context window | 128K | 128K |
Scores aggregated from five independent leaderboards. See Methodology. More head-to-heads: GPT 5.5 Instant vs Claude Mythos · GPT 5.5 Instant vs Claude Fable 5 · GPT 5.5 Instant vs Kimi K3 · GPT 5.5 Instant vs Claude Opus 5