Side-by-side technical and economic comparison between OpenAI's OpenAI o3 and OpenAI's GPT-5.6 Mini.
| Metric | OpenAI o3 | GPT-5.6 Mini | Advantage |
|---|---|---|---|
| Provider Organization | OpenAI | OpenAI | — |
| Standard Input / 1M | $2.00 | $0.30 | GPT-5.6 Mini (85% lower) |
| Cached Input / 1M | $0.50 | $0.03 | GPT-5.6 Mini lower |
| Output / 1M | $8.00 | $1.20 | GPT-5.6 Mini lower |
| Context Window | 200k | 400k | GPT-5.6 Mini (400k) |
| Max Generation Tokens | 100k | 16.4k | OpenAI o3 |
| Tokenizer Family | OpenAI o200k_base (200k vocabulary) | OpenAI o200k_base (200k vocabulary) | — |
Opt for OpenAI o3 when your engineering requirements prioritize OpenAI's ecosystem, specific tokenizer efficiencies (Exact BPE (o200k_base)), or when your expected prompt-to-completion ratios favor its $2/M input rate.
Opt for GPT-5.6 Mini when looking for OpenAI's tooling integration, specific context window depth (400k tokens), or when output generation volume favors its $1.2/M rate.