Gemini 3.1 Pro Preview vs Llama 3.1 405B
Gemini 3.1 Pro Preview (2026) and Llama 3.1 405B (2024) are compact production models from Google DeepMind and AI at Meta. Gemini 3.1 Pro Preview ships a 1m-token context window, while Llama 3.1 405B ships a 128k-token context window. On Google-Proof Q&A, Gemini 3.1 Pro Preview leads by 42.8 pts. 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 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 | Llama 3.1 405B |
|---|---|---|
| Best for | multimodal apps, tool-calling agents, and long-context analysis | general production evaluation |
| Decision fit | Coding, RAG, and Agents | Coding, Long context, and Classification |
| Context window | 1m | 128k |
| Cheapest output | $12/1M tokens | - |
| Provider routes | 5 tracked | 0 tracked |
| Shared benchmarks | Google-Proof Q&A leader | 4 shared |
Decision tradeoffs
- Gemini 3.1 Pro Preview holds a shared-benchmark lead on Google-Proof Q&A, ahead by 42.8 points.
- Gemini 3.1 Pro Preview has the larger context window for long prompts, retrieval packs, or transcript analysis.
- Gemini 3.1 Pro Preview has broader tracked provider coverage for fallback and procurement flexibility.
- Gemini 3.1 Pro Preview uniquely exposes Vision, Multimodal, and Function calling in local model data.
- Local decision data tags Gemini 3.1 Pro Preview for Coding, RAG, and Agents.
- 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
$4,600
Cheapest tracked route/tier: Google AI Studio
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 and Llama 3.1 405B; plan for SDK, billing, or endpoint changes.
- Check replacement coverage for Vision, Multimodal, and Function calling before moving production traffic.
- No overlapping tracked provider route is sourced for Llama 3.1 405B and Gemini 3.1 Pro Preview; plan for SDK, billing, or endpoint changes.
- Gemini 3.1 Pro Preview adds Vision, Multimodal, and Function calling in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2026-02-19 | 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 | Llama 3.1 405B |
|---|---|---|
| Input price |
| - |
| Output price |
| - |
| Providers | - |
Capabilities
| Capability | Gemini 3.1 Pro Preview | Llama 3.1 405B |
|---|---|---|
| Vision | Yes | No |
| Multimodal | Yes | No |
| Reasoning | No | No |
| Function calling | Yes | No |
| Tool use | Yes | No |
| Structured outputs | Yes | No |
| Code execution | Yes | No |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
| Benchmark | Gemini 3.1 Pro Preview | Llama 3.1 405B |
|---|---|---|
| Google-Proof Q&A | 94.3 | 51.5 |
| HumanEval | 94.0 | 89.0 |
| Chatbot Arena | 1493.0 | 1228.0 |
| Massive Multitask Language Understanding | 98.0 | 88.6 |
Deep dive
On shared benchmark coverage, Google-Proof Q&A has Gemini 3.1 Pro Preview at 94.3 and Llama 3.1 405B at 51.5, with Gemini 3.1 Pro Preview ahead by 42.8 points; HumanEval has Gemini 3.1 Pro Preview at 94 and Llama 3.1 405B at 89, with Gemini 3.1 Pro Preview ahead by 5 points; Chatbot Arena has Gemini 3.1 Pro Preview at 1493 and Llama 3.1 405B at 1228, with Gemini 3.1 Pro Preview ahead by 265 points. The largest visible gap is 265 points on Chatbot Arena, which matters most when that benchmark mirrors your workload. Treat isolated benchmark wins as directional, because provider routing, prompt style, and tool access can move real application results.
The capability footprint differs most on vision: Gemini 3.1 Pro Preview, multimodal input: Gemini 3.1 Pro Preview, function calling: Gemini 3.1 Pro Preview, tool use: Gemini 3.1 Pro Preview, structured outputs: Gemini 3.1 Pro Preview, and code execution: Gemini 3.1 Pro Preview. 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 has $2/1M input tokens and Llama 3.1 405B has no token price sourced yet. Provider availability is 5 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 when coding workflow support, 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.
FAQ
Which has a larger context window, Gemini 3.1 Pro Preview or Llama 3.1 405B?
Gemini 3.1 Pro Preview 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 or Llama 3.1 405B open source?
Gemini 3.1 Pro Preview 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 or Llama 3.1 405B?
Gemini 3.1 Pro Preview 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 or Llama 3.1 405B?
Gemini 3.1 Pro Preview 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 function calling, Gemini 3.1 Pro Preview or Llama 3.1 405B?
Gemini 3.1 Pro Preview 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 and Llama 3.1 405B?
Gemini 3.1 Pro Preview is available on Google AI Studio, GCP Vertex AI, OpenRouter, Replicate API, and Vercel AI Gateway. 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.
Continue comparing
Last reviewed: 2026-06-19. Data sourced from public model cards and provider documentation.