Gemini 3.1 Pro Preview Custom Tools vs Llama 3.1 405B
Gemini 3.1 Pro Preview Custom Tools (2026) and Llama 3.1 405B (2024) are compact production models from Google DeepMind and AI at Meta. Gemini 3.1 Pro Preview Custom Tools ships a 1m-token context window, while Llama 3.1 405B ships a 128k-token context window. This comparison covers specs, pricing, API access, capabilities, benchmarks, input and output token costs, and production fit for coding and agent workloads.
Gemini 3.1 Pro Preview Custom Tools fits 8x more tokens; pick it for long-context work and Llama 3.1 405B for tighter calls.
Decision scorecard
Local evidence first| Signal | Gemini 3.1 Pro Preview Custom Tools | Llama 3.1 405B |
|---|---|---|
| Best for | multimodal apps and long-context analysis | general production evaluation |
| Decision fit | RAG, Long context, and Vision | Coding, Long context, and Classification |
| Context window | 1m | 128k |
| Cheapest output | $12/1M tokens | - |
| Provider routes | 1 tracked | 0 tracked |
| Shared benchmarks | 0 shared | 0 shared |
Decision tradeoffs
- Gemini 3.1 Pro Preview Custom Tools has the larger context window for long prompts, retrieval packs, or transcript analysis.
- Gemini 3.1 Pro Preview Custom Tools has broader tracked provider coverage for fallback and procurement flexibility.
- Gemini 3.1 Pro Preview Custom Tools uniquely exposes Vision, Multimodal, and Structured outputs in local model data.
- Local decision data tags Gemini 3.1 Pro Preview Custom Tools for RAG, Long context, and Vision.
- Local decision data tags Llama 3.1 405B for Coding, Long context, and Classification.
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
Llama 3.1 405B
Unavailable
No complete token price in local provider data
Cost delta unavailable until both models have sourced input and output token prices.
Switch friction
- No overlapping tracked provider route is sourced for Gemini 3.1 Pro Preview Custom Tools and Llama 3.1 405B; plan for SDK, billing, or endpoint changes.
- Check replacement coverage for Vision, Multimodal, and Structured outputs before moving production traffic.
- No overlapping tracked provider route is sourced for Llama 3.1 405B and Gemini 3.1 Pro Preview Custom Tools; plan for SDK, billing, or endpoint changes.
- Gemini 3.1 Pro Preview Custom Tools adds Vision, Multimodal, and Structured outputs in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2026-01-01 | 2024-07-23 |
| Context window | 1m | 128k |
| Parameters | — | 405B |
| Architecture | Decoder Only | Decoder Only |
| License | Proprietary | Llama 3 Community |
| Openness | Proprietary | Open weights |
| Commercial use | Commercial use: conditional | Commercial use: conditional |
| Knowledge cutoff | 2025-01 | 2023-12 |
Pricing and availability
| Pricing attribute | Gemini 3.1 Pro Preview Custom Tools | Llama 3.1 405B |
|---|---|---|
| Input price | $2/1M tokens | - |
| Output price | $12/1M tokens | - |
| Providers | - |
Capabilities
| Capability | Gemini 3.1 Pro Preview Custom Tools | Llama 3.1 405B |
|---|---|---|
| Vision | Yes | No |
| Multimodal | Yes | No |
| Reasoning | No | No |
| Function calling | No | No |
| Tool use | No | No |
| Structured outputs | Yes | No |
| Code execution | No | No |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
No shared benchmark scores are currently available for this pair.
Deep dive
The capability footprint differs most on vision: Gemini 3.1 Pro Preview Custom Tools, multimodal input: Gemini 3.1 Pro Preview Custom Tools, and structured outputs: Gemini 3.1 Pro Preview Custom Tools. Both models share the core language-model surface, 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.
Pricing coverage is uneven: Gemini 3.1 Pro Preview Custom Tools has $2/1M input tokens and Llama 3.1 405B has no token price sourced yet. Provider availability is 1 tracked routes versus 0. Treat unknown pricing as an integration gap, then verify the route you will actually call before estimating production spend.
Choose Gemini 3.1 Pro Preview Custom Tools when long-context analysis, larger context windows, and broader provider choice are central to the workload. Choose Llama 3.1 405B 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.
FAQ
Which has a larger context window, Gemini 3.1 Pro Preview Custom Tools or Llama 3.1 405B?
Gemini 3.1 Pro Preview Custom Tools supports 1m tokens, while Llama 3.1 405B supports 128k tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible.
Is Gemini 3.1 Pro Preview Custom Tools or Llama 3.1 405B open source?
Gemini 3.1 Pro Preview Custom Tools is listed under Proprietary. Llama 3.1 405B is listed under Llama 3 Community. 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 vision, Gemini 3.1 Pro Preview Custom Tools or Llama 3.1 405B?
Gemini 3.1 Pro Preview Custom Tools has the clearer documented vision signal in this comparison. If vision is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.
Which is better for multimodal input, Gemini 3.1 Pro Preview Custom Tools or Llama 3.1 405B?
Gemini 3.1 Pro Preview Custom Tools has the clearer documented multimodal input signal in this comparison. If multimodal input is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.
Which is better for structured outputs, Gemini 3.1 Pro Preview Custom Tools or Llama 3.1 405B?
Gemini 3.1 Pro Preview Custom Tools has the clearer documented structured outputs signal in this comparison. If structured outputs 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 Llama 3.1 405B?
Gemini 3.1 Pro Preview Custom Tools is available on OpenRouter. Llama 3.1 405B is available on the tracked providers still being sourced. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
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Last reviewed: 2026-06-15. Data sourced from public model cards and provider documentation.