Gemma 4 31B — Enterprise-Grade Local LLM
Gemma 4 31B is the flagship model in Google's Gemma 4 family: 31 billion parameters, 256K token context, and top-tier output quality for production inference workloads.
What is Gemma 4 31B?
Gemma 4 31B is the flagship model in Google's Gemma 4 family. With 31 billion parameters and a 256K token context window, Gemma 4 31B is designed for production workloads, RAG pipelines, and long-document processing where output quality is the primary constraint. It requires 48GB VRAM for full BF16 inference — or 18GB with Q4 quantization — making it ideal for multi-GPU workstation setups, A100/H100 cloud instances, or high-end single-GPU rigs like the RTX 3090.
Among all open-weight models in its size class, Gemma 4 31B delivers competitive benchmark scores on coding, reasoning, instruction following, and multilingual tasks. Its 256K context window is one of the largest available in any Gemma 4 model, making Gemma 4 31B capable of ingesting entire books, large codebases, or multi-hour conversation histories in a single prompt.
Who should use Gemma 4 31B?
- •Teams deploying inference servers with A100 or H100 GPUs — Gemma 4 31B is optimized for high-throughput batch inference at datacenter scale
- •Long-document analysis tasks — the 256K context window in Gemma 4 31B enables full book ingestion, complete codebase review, and lengthy legal or financial document processing
- •RAG pipelines where retrieval quality matters — Gemma 4 31B's stronger instruction following and reasoning capabilities produce more accurate and coherent synthesized answers
- •Production API services requiring top-tier Gemma 4 output quality — when your application serves real users and output quality directly impacts retention, Gemma 4 31B is the right choice
- •Fine-tuning experiments requiring a high-capability base model — Gemma 4 31B provides a stronger starting point for domain-specific fine-tuning than smaller Gemma 4 variants
Who should not use Gemma 4 31B?
- •Consumer hardware deployments — if you don't have access to a 24GB+ GPU or multi-GPU setup, use Gemma 4 E4B instead
- •Real-time, low-latency applications — Gemma 4 31B's size means higher time-to-first-token. For chat applications needing sub-500ms response starts, consider Gemma 4 E4B
- •Edge or mobile deployment scenarios — Gemma 4 31B is not suitable for on-device inference. Use Gemma 4 E2B for embedded workloads
Technical Specifications
| Spec | Value |
|---|---|
| Parameters | 31B |
| Architecture | Dense transformer |
| Context length | 262,144 tokens (256K) |
| Min VRAM (BF16) | 64 GB |
| Min VRAM (int4 / Q4) | 18 GB |
| Multimodal | Yes (image + text) |
| Thinking Mode | Yes |
| Tool use | Yes |
| License | Gemma Terms of Use |
Recommended Runtimes for Gemma 4 31B
Gemma 4 31B is best served by production-grade inference frameworks designed for large models. Here are the three recommended options:
- •vLLM — the best option for deploying Gemma 4 31B as a production inference server. Supports OpenAI-compatible API, continuous batching, and PagedAttention for efficient VRAM use.
- •Ollama with quantization — accessible via quantized GGUF format. The Q4 variant of Gemma 4 31B brings the VRAM requirement down to 18GB, making it feasible on an RTX 3090 or RTX 4090.
- •Hugging Face Transformers — standard Python deployment with the widest ecosystem compatibility. Best for research, fine-tuning pipelines, and custom inference logic.
Quick Start with vLLM
vLLM is the recommended production runtime for Gemma 4 31B. Install and launch an OpenAI-compatible inference server with:
pip install vllm
vllm serve google/gemma-4-31b-it --max-model-len 32768Reducing max-model-len
--max-model-len 32768 caps the KV cache to 32K tokens. This significantly reduces VRAM usage during inference. If you need the full 256K context of Gemma 4 31B, remove this flag — but ensure you have sufficient VRAM for the KV cache.Quick Start with Ollama (Quantized)
For local experimentation with Gemma 4 31B on a 24GB GPU, run the quantized version through Ollama:
ollama run gemma4:27bQuality trade-offs at Q4
Gemma 4 31B Context Window
The 256K context window is Gemma 4 31B's most distinctive feature. At roughly 750 words per 1K tokens, 256K tokens corresponds to approximately 192,000 words — the length of a long novel or a medium-sized codebase. This makes Gemma 4 31B uniquely capable for tasks like full repository analysis, entire legal document review, or multi-session conversation continuity.
In practice, Gemma 4 31B performs well across the full context range when adequate VRAM is available for the KV cache. Teams building long-document RAG systems should evaluate Gemma 4 31B alongside the MoE-based Gemma 4 26B A4B, which offers 128K context at lower compute cost due to its sparse activation pattern.