GPT-5.1 vs GPT-5
GPT-5.1 is the cheaper option on input; GPT-5.1 is cheaper on output. Figures below are per million tokens, from vendor pricing cited in our reporting.
| GPT-5.1 | GPT-5 | |
|---|---|---|
| Input per 1M tokens | $1.25 | $1.25 |
| Output per 1M tokens | $10 | $10 |
| Cached input per 1M | $0.13 | $0.13 |
| Context window | 400K tokens | 400K tokens |
| Parameters | — | — |
| Licence | ||
| Benchmark | — | — |
| Vendor | OpenAI | OpenAI |
| Released | — | — |
What the numbers say
- Input price gap: 0% ($1.25 vs $1.25).
- Blended three-to-one input/output rate: $13.75 for GPT-5.1, $13.75 for GPT-5.
- Context: 400K tokens against 400K tokens.
- Licence: GPT-5.1 is ; GPT-5 is .