OpenAI o3 vs Gemini 3.1 Pro
A direct API-pricing comparison between OpenAI o3 and Gemini 3.1 Pro. Below: every cost dimension side by side, then the bottom line for a typical workload.
Bottom line
For a typical 5K-in / 1K-out request, OpenAI o3 is the cheaper choice at $0.018 per call — 1.2× less than Gemini 3.1 Pro at $0.022.
| OpenAI o3OpenAI | Gemini 3.1 ProGoogle | |
|---|---|---|
| Input / 1M tokens | $2.00 | $2.00 |
| Output / 1M tokens | $8.00 | $12.00 |
| Cached input / 1M | — | — |
| Context window | 200K | 1M |
| Provider | OpenAI |
Green = cheaper on that line. Prices are estimates from public pricing pages; verify against OpenAI and Google before relying on them.
Which is cheaper, OpenAI o3 or Gemini 3.1 Pro?
On output tokens — usually the dominant cost — OpenAI o3 charges $8.00 per million versus $12.00 for Gemini 3.1 Pro. The right pick depends on your input/output ratio and how much you can serve from cache. Use the calculator to model your exact traffic.