Ollama

Ollama is the simplest way to run open-source large language models locally on your machine. With a single command, Ollama downloads and runs Llama 3, Mistral, Phi-3, Gemma, Code Llama, and dozens of other models—providing a local ChatGPT-like experience with complete privacy, no internet requirement, and no per-token costs. It's become the standard tool for running LLMs on developer machines.

One-Command Model Running

Running any supported model is as simple as: ollama run llama3. Ollama automatically downloads the model, handles quantization for your hardware, and starts an interactive chat session. No CUDA setup, no Python environment, no model downloading complexity—just one command to start chatting with any open-source LLM.

OpenAI-Compatible API

Ollama runs a local REST API that's compatible with OpenAI's API format—meaning any application built for OpenAI can switch to local Llama 3 or Mistral by changing just the base URL. This makes Ollama a drop-in replacement for OpenAI in development environments with zero code changes.

Hardware Optimization

Ollama automatically uses your Mac's Apple Silicon GPU, NVIDIA CUDA GPU, or AMD GPU for accelerated inference. On Macs with M-series chips, Ollama achieves impressive performance running 7B-13B models at usable speeds without any configuration—making local LLMs practical on consumer hardware.

Custom Modelfiles

Ollama supports Modelfiles—a configuration format for customizing model behavior with system prompts, parameters, and base model selection. Create custom "personas" that load instantly as named models: ollama run my-coding-assistant.