GPT-5 Pro vs gpt-oss-20b
OpenAI vs OpenAI — benchmarks, pricing, and capabilities side by side.
- •GPT-5 Pro has the higher intelligence index (88.4 vs 73.6)
- •gpt-oss-20b is cheaper ($0.03 vs $15.00 per 1M input)
- •GPT-5 Pro has a larger context window (400K)
| GPT-5 Pro | gpt-oss-20b | |
|---|---|---|
| Intelligence index | 88.4 | 73.6 |
| Developer | OpenAI | OpenAI |
| Type | LLM | LLM |
| Access | API only | Open weights |
| Context window | 400,000 tokens | 131,072 tokens |
| Input price | $15.00 / 1M | $0.03 / 1M |
| Output price | $120.00 / 1M | $0.14 / 1M |
| Speed | — | 1000 tok/s |
| Released | October 6, 2025 | August 5, 2025 |
| Parameters | — | 21B (3.6B active) |
| Input modalities | Text, Image | Text |
| Output modalities | Text | Text |
Shared benchmarks
GPT-5 Pro
gpt-oss-20b
GPQA Diamond
88.4
71.5
Humanity’s Last Exam
42
17.3