Why you'd want it
vLLM is an inference and serving engine built around PagedAttention, continuous batching, chunked prefill and prefix caching, with many quantization formats and speculative decoding. It runs an OpenAI-compatible API server plus Anthropic Messages API and gRPC support, with tool calling and reasoning parsers and structured outputs via xgrammar or guidance. Tensor, pipeline, data and expert parallelism cover distributed inference, and it supports 200+ Hugging Face model architectures on NVIDIA, AMD and Intel GPUs, CPUs and hardware plugins.
Best for
- Self-hosting open models on GPUs
- Serving many concurrent agent requests
- Distributed multi-GPU inference
Use it when
You need to serve open-weight models to agents or apps at scale on your own GPU infrastructure.
Skip it if
You are on Windows, which vLLM does not support natively (use WSL), or you only want to try a model on a laptop, where a lighter local runner is simpler to set up.