What Is Ollama? A Beginner's Guide to Running AI Models Locally

If you have heard people talk about running AI “locally” or “on your own machine,” Ollama is usually the tool they mean. This is a plain-English guide to what it is, why people use it, and how to try it.

Key takeaways

• Ollama is a free, open-source tool for running open large language models on your own computer.
• The model runs on your hardware, so your conversations stay on your machine and there is no per-message cost.
• It is simple to start: one command downloads a model and starts a chat.
• Apps connect to it. Ollama runs a small local server, which is how other tools, including phone apps, talk to your models.

What Ollama is

Ollama is a free tool that lets you download and run large language models on your own computer. A large language model is the kind of AI behind chat assistants. Normally you reach one over the internet on a company’s servers. Ollama flips that around and runs the model on your machine.

It works on macOS, Windows, and Linux, and it handles the fiddly parts for you: downloading the model, loading it, and giving you a way to chat with it.

Why people run models locally

• Privacy. Your prompts and the model’s answers stay on hardware you control, rather than going to a third-party AI service.
• Cost. There is no per-message or per-token bill. Once a model is downloaded, you can use it as much as you like.
• Offline. After the first download, a model runs without an internet connection.
• Control. You choose the exact model and version, and it does not change under you.

What you can run with it

Ollama runs open models such as Llama, Mistral, Gemma, Qwen, and Phi, in a range of sizes. The size matters: smaller models run comfortably on an everyday laptop, while larger ones want a stronger GPU and more memory. A good starting point is a small, capable model like llama3.2, which runs on modest hardware.

How it works

Once Ollama is installed, you pull and run a model with a single command:

ollama run llama3.2

The first time, it downloads the model. After that, you are chatting in your terminal.

Behind the scenes, Ollama also runs a small local server (by default at http://127.0.0.1:11434). That server is the important part for everything else: it exposes a simple API, which is how other programs talk to your models. Code editors, desktop chat apps, and phone clients all connect to that same endpoint.

Ollama Cloud

Not everyone has a machine that can run the biggest models. Ollama Cloud is a hosted option that runs models on Ollama’s servers instead of your own. You trade some of the local privacy for the ability to use larger models from a light device. Many tools, including phone apps, can point at either your own server or Ollama Cloud.

What you need to get started

1. A computer running macOS, Windows, or Linux.
2. Ollama installed.
3. One model pulled, for example ollama pull llama3.2.

That is enough to chat from your terminal. From there, you can add a friendlier interface.

Using Ollama from your phone

Ollama runs on a computer, but you do not have to sit at that computer to use it. A client app on your phone can connect to your Ollama server over your home Wi-Fi, or to Ollama Cloud, and let you chat from anywhere.

Ollama Mobile is one such client. It is an unofficial, community-built app, and it connects to the Ollama setup you control. Your phone is the client, and the server still runs the model.

If you want to set this up, start with the guide to using Ollama on your phone, then follow the iPhone or Android walkthrough.

Frequently asked questions

What is Ollama in simple terms?

Ollama is a free tool that downloads and runs open large language models on your own computer. You type a command or open an app, and the model answers from your machine instead of a company server.

Is Ollama free?

Yes. Ollama itself is free and open source, and the open models you run with it are free to download. Ollama also offers a paid hosted option called Ollama Cloud for running larger models without your own hardware.

What models can Ollama run?

Ollama runs open models such as Llama, Mistral, Gemma, Qwen, and Phi, in a range of sizes. You pick a model that fits your computer, and smaller models run on modest hardware.

Does Ollama work offline?

Once you have downloaded a model, Ollama runs it locally, so it works without an internet connection. You only need the internet to download a model the first time or to use Ollama Cloud.

Can I use Ollama on my phone?

Ollama runs on a computer, not your phone. To use it from your phone you connect a client app to your Ollama server or to Ollama Cloud. Ollama Mobile is one such client, and it is an unofficial, community-built app.

Next steps

New to all of this? Install Ollama, run ollama run llama3.2, and have a first chat in your terminal. When you want it on your phone, come back to the full guide.