Gemini 3.1 Pro Preview Custom Tools vs GPT-4o Search Preview
Gemini 3.1 Pro Preview Custom Tools (2026) and GPT-4o Search Preview (2025) are compact production models from Google DeepMind and OpenAI. Gemini 3.1 Pro Preview Custom Tools ships a 1M-token context window, while GPT-4o Search Preview ships a 128K-token context window. On pricing, Gemini 3.1 Pro Preview Custom Tools costs $2/1M input tokens versus $2.5/1M for the alternative. This comparison covers specs, pricing, capabilities, benchmarks, provider availability, and production fit.
Gemini 3.1 Pro Preview Custom Tools fits 8x more tokens; pick it for long-context work and GPT-4o Search Preview for tighter calls.
Specs
| Released | 2026-01-01 | 2025-02-26 |
| Context window | 1M | 128K |
| Parameters | — | — |
| Architecture | decoder only | decoder only |
| License | Unknown | Unknown |
| Knowledge cutoff | - | - |
Pricing and availability
| Gemini 3.1 Pro Preview Custom Tools | GPT-4o Search Preview | |
|---|---|---|
| Input price | $2/1M tokens | $2.5/1M tokens |
| Output price | $12/1M tokens | $10/1M tokens |
| Providers |
Capabilities
| Gemini 3.1 Pro Preview Custom Tools | GPT-4o Search Preview | |
|---|---|---|
| Vision | ||
| Multimodal | ||
| Reasoning | ||
| Function calling | ||
| Tool use | ||
| Structured outputs | ||
| Code execution |
Benchmarks
No shared benchmark rows are currently sourced for this pair.
Deep dive
The capability footprint is close: both models cover structured outputs. That makes context budget, benchmark fit, and provider maturity more important than a simple checklist. If your application depends on one integration detail, verify it against the provider route you plan to use, not just the base model listing.
For cost, Gemini 3.1 Pro Preview Custom Tools lists $2/1M input and $12/1M output tokens, while GPT-4o Search Preview lists $2.5/1M input and $10/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts GPT-4o Search Preview lower by about $0.25 per million blended tokens. Availability is 1 providers versus 1, so concentration risk also matters.
Choose Gemini 3.1 Pro Preview Custom Tools when long-context analysis, larger context windows, and lower input-token cost are central to the workload. Choose GPT-4o Search Preview when provider fit are more important. For production, rerun your own prompts through the exact provider, region, and tool stack you plan to ship. This keeps the decision grounded in measurable tradeoffs instead of brand-level assumptions. It also helps separate model capability from provider packaging, which can change cost and latency.
FAQ
Which has a larger context window, Gemini 3.1 Pro Preview Custom Tools or GPT-4o Search Preview?
Gemini 3.1 Pro Preview Custom Tools supports 1M tokens, while GPT-4o Search Preview supports 128K tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible.
Which is cheaper, Gemini 3.1 Pro Preview Custom Tools or GPT-4o Search Preview?
Gemini 3.1 Pro Preview Custom Tools is cheaper on tracked token pricing. Gemini 3.1 Pro Preview Custom Tools costs $2/1M input and $12/1M output tokens. GPT-4o Search Preview costs $2.5/1M input and $10/1M output tokens. Provider discounts or batch pricing can still change the final bill.
Is Gemini 3.1 Pro Preview Custom Tools or GPT-4o Search Preview open source?
Gemini 3.1 Pro Preview Custom Tools is listed under Unknown. GPT-4o Search Preview is listed under Unknown. License labels affect whether you can self-host, redistribute weights, or rely only on hosted APIs, so confirm the upstream license before deployment.
Which is better for structured outputs, Gemini 3.1 Pro Preview Custom Tools or GPT-4o Search Preview?
Both Gemini 3.1 Pro Preview Custom Tools and GPT-4o Search Preview expose structured outputs. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface.
Where can I run Gemini 3.1 Pro Preview Custom Tools and GPT-4o Search Preview?
Gemini 3.1 Pro Preview Custom Tools is available on OpenRouter. GPT-4o Search Preview is available on OpenRouter. Provider coverage can affect latency, region availability, compliance posture, and fallback options. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.
When should I pick Gemini 3.1 Pro Preview Custom Tools over GPT-4o Search Preview?
Gemini 3.1 Pro Preview Custom Tools fits 8x more tokens; pick it for long-context work and GPT-4o Search Preview for tighter calls. If your workload also depends on long-context analysis, start with Gemini 3.1 Pro Preview Custom Tools; if it depends on provider fit, run the same evaluation with GPT-4o Search Preview.
Continue comparing
Last reviewed: 2026-04-24. Data sourced from public model cards and provider documentation.