nanobrowser

Nanobrowser is an open-source Chrome extension that runs an AI web-automation agent inside your own browser. It positions itself as a free alternative to OpenAI Operator: instead of a subscription, you connect your own API keys and pay only for the model usage you incur.

It suits people who want an agent to carry out tasks on websites, such as research across several pages, comparing products or filling in repetitive forms, without sending their browsing session to a cloud service. A multi-agent system splits the work: a planner decides what to do and corrects course when it hits obstacles, while a navigator carries out actions on the page. A side-panel chat shows real-time status. It supports OpenAI, Anthropic, Gemini, DeepSeek, Grok, Azure OpenAI, OpenRouter, Ollama and custom OpenAI-compatible providers, and you can assign different models to different agents.

Getting started: install Nanobrowser from the Chrome Web Store, open the side panel, add an API key for your preferred provider (or a local Ollama endpoint), choose models for the planner and navigator, and describe the task.