AI model matchup
GPT-5.3 Codex vs Step-3.5-Flash
A side-by-side look at published capability scores, listed API pricing, speed, context, and license - to help you decide which trade-offs fit your work.
GPT-5.3 CodexvsStep-3.5-Flash
Step-3.5-Flash leads the RankLLMs Index by 0.2 points (37.3 vs 37.1). Verified API Pricing: $1.75 (GPT-5.3 Codex) vs $0.10 (Step-3.5-Flash) per 1M tokens.
Capability profile
Speed duel
tpsPrice duel
$/1MShorter bar = cheaper. Blended per 1M tokens.
| Metric | GPT-5.3 Codex | Step-3.5-Flash |
|---|---|---|
| RankLLMs Overall Score | 37.1 pts | 37.3 pts ▲ |
| Reasoning | 37.9 ▲ | 37.3 |
| Coding | 31.9 ▲ | 20.8 |
| Agentic Tool Use | 24.4 ▲ | 16.0 |
| Code Arena Elo | 1374 ▲ | 762 |
| Inference Speed | 18 tps | 84 tps ▲ |
| API Price (per 1M tokens) | $1.75 | $0.10 ▲ |
| Context Window | 400K | 256K |
| License | Proprietary | Open Source |
| Global Rank | #72 | #70 ▲ |
Decision notes
What the numbers suggest
Step-3.5-Flash leads the RankLLMs overall score by 0.2 points. Step-3.5-Flash has the lower listed API rate ($0.10 per 1M tokens).
Treat the overall index as a starting point, then prioritize the benchmark that resembles your task. Published scores and provider pricing can change; this comparison does not represent a first-party test of either model.
- Overall index
- Step-3.5-Flash leads
- 37.1 to 37.3 pts
- Coding score
- GPT-5.3 Codex leads
- 31.9 to 20.8 pts
- Reasoning score
- GPT-5.3 Codex leads
- 37.9 to 37.3 pts
- Agentic score
- GPT-5.3 Codex leads
- 24.4 to 16.0 pts
Choose by workload
Which profile fits your use?
OpenAI
Consider GPT-5.3 Codex when
your workload gives more weight to the higher listed coding score, the higher listed reasoning score. Compare those signals with your own task mix, latency needs, and budget.
View GPT-5.3 Codex profileStepFun
Consider Step-3.5-Flash when
your workload gives more weight to the higher overall index score, the lower listed API rate. Compare those signals with your own task mix, latency needs, and budget.
View Step-3.5-Flash profile