Gemini 3.1 Pro vs GPT-5.5
Side-by-side comparison of pricing, context window, modalities, licensing, and strengths — with practical guidance on which model fits which workload.
| Spec | Gemini 3.1 Pro | GPT-5.5 |
|---|---|---|
| Provider | OpenAI | |
| Context window | 1M tokens | 1M tokens |
| Input price (per 1M tokens) | $2.00 | $5.00 |
| Output price (per 1M tokens) | $12.00 | $30.00 |
| Example workload (10M in + 2M out) | $44.00 / month | $110.00 / month |
| Modalities | text, image, audio, video, code | text, image, audio, code |
| Knowledge cutoff | Not disclosed | Not disclosed |
| Release date | 2026 | 2026 |
| License | Proprietary | Proprietary |
| Strengths | Multimodal reasoning, Computer use, Video input, Long context | Flagship reasoning, Agentic tool use, Multimodal, Coding |
| Open weights | No | No |
Verdict
Google’s multimodal flagship against OpenAI’s. Gemini 3.1 Pro is the price aggressor at $2/$12 per million tokens (rising to $4/$18 past 200K input) versus GPT-5.5’s $5/$30, and it uniquely accepts video input and leads on computer-use benchmarks. GPT-5.5 answers with audio modality, a slightly larger effective context, and the deepest third-party integration ecosystem in the industry. On raw reasoning the two trade wins by task — run both on your own evals before committing.
When to choose Gemini 3.1 Pro
Pick Gemini 3.1 Pro for video understanding, computer-use agents, lower per-token cost, and Google Cloud integration.
When to choose GPT-5.5
Pick GPT-5.5 for audio interactions, ecosystem breadth, and the most battle-tested function-calling stack.
Prices and specs reflect published provider information and change frequently — always confirm on the provider's pricing page before committing to a workload.
Frequently asked questions
Which is cheaper: Gemini 3.1 Pro or GPT-5.5?
Gemini 3.1 Pro is cheaper per token: $2.00 input / $12.00 output per 1M tokens, versus $5.00 / $30.00 for GPT-5.5. Actual costs depend on your input-to-output ratio — try the AI cost calculator for your own numbers.
Which has the larger context window?
GPT-5.5 supports 1M tokens versus 1M for Gemini 3.1 Pro — roughly 1.0× more room for documents, code, and conversation history.
Can I self-host either model?
No — both models are proprietary and available only through their providers' APIs or cloud platforms.
How should I test which model is better for my use case?
Benchmarks are a starting point, not an answer. Run both models on 20–50 examples of your real task and compare outputs blind. Use our token counter to estimate prompt sizes and the cost calculator to project monthly spend before committing.