Gemini 3.1 Pro Preview Custom Tools vs Trinity-Large-Thinking
Gemini 3.1 Pro Preview Custom Tools (2026) and Trinity-Large-Thinking (2026) are frontier reasoning models from Google DeepMind and Arcee AI. Gemini 3.1 Pro Preview Custom Tools ships a 1m-token context window, while Trinity-Large-Thinking ships a 256k-token context window. On pricing, Trinity-Large-Thinking costs $0.22/1M input tokens versus $2/1M for the alternative. This comparison covers specs, pricing, API access, capabilities, benchmarks, input and output token costs, and production fit for coding and agent workloads.
Trinity-Large-Thinking is ~809% cheaper at $0.22/1M; pay for Gemini 3.1 Pro Preview Custom Tools only for long-context analysis.
Decision scorecard
Local evidence first| Signal | Gemini 3.1 Pro Preview Custom Tools | Trinity-Large-Thinking |
|---|---|---|
| Best for | long-context analysis | reasoning-heavy apps, tool-calling agents, and provider-routed production |
| Decision fit | RAG, Long context, and Classification | RAG, Agents, and Long context |
| Context window | 1m | 256k |
| Cheapest output | $12/1M tokens | $0.85/1M tokens |
| Provider routes | 1 tracked | 3 tracked |
| Shared benchmarks | 0 rows | 0 rows |
Decision tradeoffs
- Gemini 3.1 Pro Preview Custom Tools has the larger context window for long prompts, retrieval packs, or transcript analysis.
- Local decision data tags Gemini 3.1 Pro Preview Custom Tools for RAG, Long context, and Classification.
- Trinity-Large-Thinking has the lower cheapest tracked output price at $0.85/1M tokens.
- Trinity-Large-Thinking has broader tracked provider coverage for fallback and procurement flexibility.
- Trinity-Large-Thinking uniquely exposes Reasoning, Function calling, and Tool use in local model data.
- Local decision data tags Trinity-Large-Thinking for RAG, Agents, and Long context.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output route or tier on this page.
Gemini 3.1 Pro Preview Custom Tools
$4,600
Cheapest tracked route/tier: OpenRouter
Trinity-Large-Thinking
$389
Cheapest tracked route/tier: OpenRouter
Estimated monthly gap: $4,212. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.
Switch friction
- Provider overlap exists on OpenRouter; start route-level A/B tests there.
- Trinity-Large-Thinking is $11.15/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- Trinity-Large-Thinking adds Reasoning, Function calling, and Tool use in local capability data.
- Provider overlap exists on OpenRouter; start route-level A/B tests there.
- Gemini 3.1 Pro Preview Custom Tools is $11.15/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- Check replacement coverage for Reasoning, Function calling, and Tool use before moving production traffic.
Specs
| Specification | ||
|---|---|---|
| Released | 2026-01-01 | 2026-04-01 |
| Context window | 1m | 256k |
| Parameters | — | 400B |
| Architecture | decoder only | Sparse Mixture of Experts (MoE) |
| License | Proprietary | Apache 2.0 |
| Knowledge cutoff | 2025-01 | - |
Pricing and availability
| Pricing attribute | Gemini 3.1 Pro Preview Custom Tools | Trinity-Large-Thinking |
|---|---|---|
| Input price | $2/1M tokens | $0.22/1M tokens |
| Output price | $12/1M tokens | $0.85/1M tokens |
| Providers |
Capabilities
| Capability | Gemini 3.1 Pro Preview Custom Tools | Trinity-Large-Thinking |
|---|---|---|
| Vision | No | No |
| Multimodal | No | No |
| Reasoning | No | Yes |
| Function calling | No | Yes |
| Tool use | No | Yes |
| Structured outputs | Yes | Yes |
| Code execution | No | No |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
No shared benchmark rows are currently sourced for this pair.
Deep dive
The capability footprint differs most on reasoning mode: Trinity-Large-Thinking, function calling: Trinity-Large-Thinking, and tool use: Trinity-Large-Thinking. Both models share structured outputs, so the practical split is not just feature count. Use those differences to decide whether the page is about raw model quality, agentic coding support, multimodal ingestion, or predictable structured API behavior.
For cost, Gemini 3.1 Pro Preview Custom Tools lists $2/1M input and $12/1M output tokens on the cheapest tracked provider, while Trinity-Large-Thinking lists $0.22/1M input and $0.85/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts Trinity-Large-Thinking lower by about $4.59 per million blended tokens. Availability is 1 providers versus 3, 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 Trinity-Large-Thinking when reasoning depth, lower input-token cost, and broader provider choice 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 Trinity-Large-Thinking?
Gemini 3.1 Pro Preview Custom Tools supports 1m tokens, while Trinity-Large-Thinking supports 256k 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 Trinity-Large-Thinking?
Trinity-Large-Thinking is cheaper on tracked token pricing. Gemini 3.1 Pro Preview Custom Tools costs $2/1M input and $12/1M output tokens. Trinity-Large-Thinking costs $0.22/1M input and $0.85/1M output tokens. Provider discounts or batch pricing can still change the final bill.
Is Gemini 3.1 Pro Preview Custom Tools or Trinity-Large-Thinking open source?
Gemini 3.1 Pro Preview Custom Tools is listed under Proprietary. Trinity-Large-Thinking is listed under Apache 2.0. 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 reasoning mode, Gemini 3.1 Pro Preview Custom Tools or Trinity-Large-Thinking?
Trinity-Large-Thinking has the clearer documented reasoning mode signal in this comparison. If reasoning mode is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.
Which is better for function calling, Gemini 3.1 Pro Preview Custom Tools or Trinity-Large-Thinking?
Trinity-Large-Thinking has the clearer documented function calling signal in this comparison. If function calling is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.
Where can I run Gemini 3.1 Pro Preview Custom Tools and Trinity-Large-Thinking?
Gemini 3.1 Pro Preview Custom Tools is available on OpenRouter. Trinity-Large-Thinking is available on Arcee AI, OpenRouter, and Vercel AI Gateway. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
Continue comparing
Last reviewed: 2026-05-22. Data sourced from public model cards and provider documentation.