Gemini 3.1 Pro Preview Custom Tools vs GPT-4o-mini Search Preview
Gemini 3.1 Pro Preview Custom Tools (2026) and GPT-4o-mini 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-mini Search Preview ships a 128K-token context window. On pricing, GPT-4o-mini Search Preview costs $0.15/1M input tokens versus $2/1M for the alternative. This comparison covers specs, pricing, capabilities, benchmarks, provider availability, and production fit.
GPT-4o-mini Search Preview is ~1233% cheaper at $0.15/1M; pay for Gemini 3.1 Pro Preview Custom Tools only for long-context analysis.
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-mini Search Preview | |
|---|---|---|
| Input price | $2/1M tokens | $0.15/1M tokens |
| Output price | $12/1M tokens | $0.6/1M tokens |
| Providers |
Capabilities
| Gemini 3.1 Pro Preview Custom Tools | GPT-4o-mini 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-mini Search Preview lists $0.15/1M input and $0.6/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts GPT-4o-mini Search Preview lower by about $4.71 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 and larger context windows are central to the workload. Choose GPT-4o-mini Search Preview when provider fit and lower input-token cost 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-mini Search Preview?
Gemini 3.1 Pro Preview Custom Tools supports 1M tokens, while GPT-4o-mini 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-mini Search Preview?
GPT-4o-mini Search Preview is cheaper on tracked token pricing. Gemini 3.1 Pro Preview Custom Tools costs $2/1M input and $12/1M output tokens. GPT-4o-mini Search Preview costs $0.15/1M input and $0.6/1M output tokens. Provider discounts or batch pricing can still change the final bill.
Is Gemini 3.1 Pro Preview Custom Tools or GPT-4o-mini Search Preview open source?
Gemini 3.1 Pro Preview Custom Tools is listed under Unknown. GPT-4o-mini 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-mini Search Preview?
Both Gemini 3.1 Pro Preview Custom Tools and GPT-4o-mini 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-mini Search Preview?
Gemini 3.1 Pro Preview Custom Tools is available on OpenRouter. GPT-4o-mini 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-mini Search Preview?
GPT-4o-mini Search Preview is ~1233% cheaper at $0.15/1M; pay for Gemini 3.1 Pro Preview Custom Tools only for long-context analysis. 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-mini Search Preview.
Continue comparing
Last reviewed: 2026-04-24. Data sourced from public model cards and provider documentation.