Side-by-side technical and economic comparison between OpenAI's GPT-5.6 Sol and Google's Gemini 2.5 Flash.
| Metric | GPT-5.6 Sol | Gemini 2.5 Flash | Advantage |
|---|---|---|---|
| Provider Organization | OpenAI | — | |
| Standard Input / 1M | $4.00 | $0.30 | Gemini 2.5 Flash (93% lower) |
| Cached Input / 1M | $0.40 | $0.03 | Gemini 2.5 Flash lower |
| Output / 1M | $20.00 | $2.50 | Gemini 2.5 Flash lower |
| Context Window | 1.05M | 1.05M | GPT-5.6 Sol (1.05M) |
| Max Generation Tokens | 16.4k | 8.2k | GPT-5.6 Sol |
| Tokenizer Family | OpenAI o200k_base (200k vocabulary) | Google Gemma SentencePiece (~256k vocabulary) | — |
Opt for GPT-5.6 Sol 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 $4/M input rate.
Opt for Gemini 2.5 Flash when looking for Google's tooling integration, specific context window depth (1.05M tokens), or when output generation volume favors its $2.5/M rate.