Build Your Own Free Offline AI Chatbot Using Ollama + Open WebUI (Complete Guide)

Introduction

Most AI chatbots today — including cloud-based assistants — require:

• Continuous internet access
• API payments
• Privacy trade-offs
• Usage limits

However, modern open-source LLMs (Large Language Models) allow you to run a fully private AI assistant locally on your computer.

This guide explains how to build a ChatGPT-like interface running completely offline using:

• Ollama → Runs AI models locally
• Open WebUI → Provides a browser chat interface
• Docker → Hosts the UI environment

At the end of this tutorial you will have:

✔ A private AI assistant
✔ Unlimited usage
✔ No API cost
✔ Works without internet (after download)
✔ Supports coding, writing, research & automation

System Requirements

Architecture Overview

User Browser
     ↓
Open WebUI (Interface)
     ↓
Ollama (Model Runner)
     ↓
Local AI Model (Llama / Mistral / DeepSeek)

The model runs entirely inside your PC memory — no external servers.

Step 1 — Install Ollama (AI Engine)

Ollama is responsible for downloading and running LLM models locally.

Download

Go to:
https://ollama.com/download

Install normally like any Windows software.

Verify Installation

Open Command Prompt / PowerShell and run:

ollama

If installed correctly, the CLI help menu appears.

Step 2 — Install Your First AI Model

Now you install the actual AI brain.

We recommend starting with Meta Llama 3.

ollama run llama3

What Happens Now

• The system downloads ~4–5GB model
• Model is stored locally
• After download, no internet is required again

You now already have a working terminal chatbot.

Try:

Explain Internet of Things
Write a Python calculator
Summarize World War 2

Step 3 — Install Docker (Required for Web Interface)

Open WebUI runs inside a container.

Download Docker Desktop:
https://www.docker.com/products/docker-desktop/

Installation Notes

• Enable WSL2 when prompted
• Restart PC after install
• Login optional (skip allowed)

Verify Docker

docker --version

Step 4 — Install ChatGPT-Style Interface (Open WebUI)

Now we convert terminal AI into a real web chat app.

Run in PowerShell:

docker run -d -p 3000:8080 -v open-webui:/app/backend/data --name open-webui ghcr.io/open-webui/open-webui:main

Docker downloads the interface automatically.

Step 5 — Access Your AI Chatbot

Open browser:

http://localhost:3000

Create an account (local only).

You now have a full ChatGPT-like interface running locally.

Step 6 — Install Additional Models (Recommended)

You can install multiple specialized AIs.

General Purpose (Fast)

ollama pull mistral

Coding Specialist

ollama pull deepseek-coder

Balanced & Smart

ollama pull llama3:8b

Switch models inside the UI anytime.

How the System Works

Offline Mode

After models are downloaded:

• Turn off Wi-Fi
• Chat still works

This confirms full local execution.

Storage Location

Models stored at:

C:\Users\USERNAME\.ollama\models

You can back them up or move them to another PC.

Updating Models

ollama pull llama3

Ollama automatically updates to latest version.

Removing Models

ollama list
ollama rm mistral

Performance Optimization

Improve Speed

• Close Chrome tabs
• Use smaller models (7B / 8B)
• Increase RAM
• Use SSD storage

Low RAM Mode

Best models for 8GB systems:

• mistral
• llama3:8b

Avoid 13B+ models.

Common Issues & Fixes

Port Already in Use

Change port:

docker run -d -p 3001:8080 ghcr.io/open-webui/open-webui:main

Ollama Not Detected in UI

Restart Ollama service:

ollama serve

Slow Responses

Normal — CPU inference is slower than cloud GPUs.

Security & Privacy

This setup provides maximum privacy:

• No data leaves your PC
• No telemetry
• No external API
• Safe for confidential documents

What You Can Do With It

• Coding assistant
• Research helper
• Content writing
• Offline documentation search
• Personal knowledge base
• Automation planning
• Technical debugging
• IoT project assistance

Conclusion

By combining Ollama and Open WebUI, you can build a completely private AI assistant comparable to commercial chatbots — without cost or internet dependency.

This setup is ideal for:

• Developers
• Researchers
• Businesses handling sensitive data
• Offline environments
• Long-term AI usage

You now own your AI — not rent it.