# AI21 vs vLLM — Fit & Features

Canonical: https://trutool.co/compare/ai21-vs-vllm
Author: Snehil (https://trutool.co/authors/snehil)

Compare AI21 and vLLM by use case, features, limitations, and evaluation questions.

## Compare fit, features, and limitations

### AI21
Language models and enterprise AI systems.
Best fit: Developers evaluating model APIs or inference infrastructure.
- Language models and enterprise AI systems
Before you choose: Compare latency, usage billing, rate limits, model licenses, and data handling for your workload.
Pricing: https://www.ai21.com/
- [Read AI21 profile](https://trutool.co/tools/ai21): Read AI21 profile

### vLLM
Serve language models with an open-source inference engine.
Best fit: Machine learning teams building, serving, and operating model workloads.
- LLM serving
- Batching
- API server
Before you choose: Benchmark your workload, verify model licenses and hardware requirements, and compare inference, hosting, and storage costs.
Pricing: https://docs.vllm.ai/en/latest/
- [Read vLLM profile](https://trutool.co/tools/vllm): Read vLLM profile