GPT OSS 20B vs Step 3.5 Flash
Both have similar output pricing, while Step 3.5 Flash offers a larger context window. Choose GPT OSS 20B or Step 3.5 Flash based on the trade-off between cost, context, and the benchmarks that matter for your use case.
| Spec | GPT OSS 20B | Step 3.5 Flash |
|---|---|---|
| Provider | Neon | StepFun |
| Input / 1M tokens | $0.07 | $0.10 |
| Output / 1M tokens | $0.30 | $0.30 |
| Context window | 131K | 262K |
| Parameters | 21B | — |
| Open weights | Yes | Yes |
| Released | Aug 2025 | Jan 2026 |
| LMArena (Chatbot Arena) Elo score | — | 1403 |
FAQ
Is GPT OSS 20B or Step 3.5 Flash cheaper?
GPT OSS 20B and Step 3.5 Flash have comparable output pricing.
Which has the larger context window, GPT OSS 20B or Step 3.5 Flash?
Step 3.5 Flash has the larger context window (262K tokens).
Pricing is indicative — confirm with the provider before production use. Highlighted values indicate the better figure for that row.