ModelRefs / vLLM — AI Glossary
vLLM — AI Glossary
An open-source, high-throughput LLM inference engine built on PagedAttention and continuous batching. Self-hosting open-weight models with real concurrency
Overview
vLLM is the de-facto open serving stack for open-weights models, supporting tensor parallelism, speculative decoding, LoRA hot-swap, and OpenAI-compatible APIs. Widely adopted in production for self-hosted Llama, Mistral, and Qwen deployments.
Reference details
| Topic | infrastructure |
|---|---|
| Last reviewed | 2026-06-24 |
Related terms
Example: Why continuous batching matters
With static batching, a batch of eight requests waits for the slowest to finish before any slot frees. Continuous batching evicts each sequence as it completes and admits a new one immediately, so the GPU is not idling on finished slots. That scheduling difference, not a faster kernel, is where most of the throughput gain comes from.
Commonly confused with
vLLM is an inference server, not a model and not a framework for building applications. It serves open-weight models over an OpenAI-compatible API. It does not fine-tune, does not orchestrate, and is not an alternative to a gateway — those sit at different layers.
When to use it
Reach for it when:
- Self-hosting open-weight models with real concurrency
- You need PagedAttention or LoRA hot-swap at serving time
- You want an OpenAI-compatible surface over your own hardware
Reach for something else when:
- You use hosted APIs — the provider already runs something like it
- Single-user or batch workloads, where a simpler runtime is easier to operate
- Nobody owns GPU operations; a serving stack is infrastructure to run
Continue your research
Use these connected ModelRefs sections to compare alternatives, inspect implementation paths, and review the evidence and governance boundaries relevant to vLLM — AI Glossary.
Frequently asked questions
What is vLLM?
An open-source, high-throughput LLM inference engine built on PagedAttention and continuous batching.
What concepts are related to vLLM?
Closely related concepts include paged attention, continuous batching, inference.