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Ollama vs vLLM: which one to choose in 2026?

Both are open source alternatives to OpenAI API. We compare license, tech stack and features to help you decide which fits your team best.

OllamavLLM
CategoryArtificial IntelligenceArtificial Intelligence
LicenseMITApache-2.0
GitHub stars 99k 29k
Tech stackGo, Llama.cppPython, CUDA
ReplacesOpenAI APIOpenAI API

Ollama has more GitHub stars, which usually indicates a larger community (not necessarily that it's the best option for your use case).

Ollama

Run open source LLMs locally, an alternative to the OpenAI API.

Pros

  • Your data never leaves your server

Things to consider

  • Quality depends on the model and hardware available
View Ollama's full profile

vLLM

High-performance LLM inference engine, an alternative to the OpenAI API in production.

Pros

  • Purpose-built for serving LLMs in production at scale

Things to consider

  • Requires a GPU with enough VRAM for the chosen model
View vLLM's full profile

Key features

Ollama

  • Download models with a single command
  • API compatible with multiple clients
  • GPU and CPU support

vLLM

  • Much higher throughput thanks to PagedAttention
  • OpenAI-compatible API
  • Supports dozens of model architectures