Model comparison
GPT-5.5 vs Gemini 3.1 Pro
Gemini 3.1 Pro is the cheaper of the two on input tokens, by a factor of 2.5. GPT-5.5 lists $5 in and $30 out per million tokens with a 1M context window; Gemini 3.1 Pro lists $2 and $12 with 2M.
| GPT-5.5 | Gemini 3.1 Pro | |
|---|---|---|
| Developer | OpenAI | |
| Input / 1M tokens | $5 | $2 |
| Output / 1M tokens | $30 | $12 |
| Context window | 1M | 2M |
| Max output | - | - |
| Modality | Multimodal | Multimodal |
| Open weights | No | No |
| Released | 2026 | 2026 |
| Source | Secondary, verify | Secondary, verify |
| Illustrative month* | $330 | $132 |
* 100 calls a day, about 10,000 tokens in and 2,000 out each, at list price, before caching, batching or volume discounts. Illustrative only. Pricing and context data verified 2026-08-07; "Secondary" figures come from pricing aggregators and trade press, so check the provider before relying on them. No benchmark scores: see methodology.
GPT-5.5
The previous flagship, with a 1M-token context window and strong coding and agentic performance. Still available and widely deployed.
GPT-5.5 in full →Gemini 3.1 Pro
Google's flagship and the largest context window of any major commercial model at 2M tokens. Pricing is tiered: it doubles on input above 200K tokens, which matters a great deal if you actually use the window.
- Watch: Tiered pricing above 200K input tokens catches people out
Other comparisons