Synth 2.5 Flash Preview vs gpt-oss-20b (batch)
Synth 2.5 Flash Preview is cheaper on output tokens, while gpt-oss-20b (batch) offers a larger context window. Choose Synth 2.5 Flash Preview or gpt-oss-20b (batch) based on the trade-off between cost, context, and the benchmarks that matter for your use case.
| Spec | Synth 2.5 Flash Preview | gpt-oss-20b (batch) |
|---|---|---|
| Provider | NanoGPT | OpenAI |
| Input / 1M tokens | $0.03 | $0.02 |
| Output / 1M tokens | $0.10 | $0.11 |
| Context window | 30K | 131K |
| Parameters | — | 21B |
| Open weights | No | Yes |
| Released | Sep 2026 | Aug 2025 |
| LMArena (Chatbot Arena) Elo score | — | 1288 |
| GPQA Diamond score | — | 60.8 |
| Epoch Capabilities Index score | — | 138 |
FAQ
Is Synth 2.5 Flash Preview or gpt-oss-20b (batch) cheaper?
Synth 2.5 Flash Preview is cheaper on output tokens ($0.10 vs $0.11 per 1M).
Which has the larger context window, Synth 2.5 Flash Preview or gpt-oss-20b (batch)?
gpt-oss-20b (batch) has the larger context window (131K tokens).
Pricing is indicative — confirm with the provider before production use. Highlighted values indicate the better figure for that row.