Sigma AI Browser

Sigma is a Chromium-based browser from Sigmabrowser OÜ in Tallinn, Estonia, that puts AI and privacy features into the browser itself rather than into an extension. It runs on macOS, Windows and iPhone, keeps support for Chrome extensions, and adds a built-in ad blocker, encrypted private profiles secured by a 12-word recovery phrase, and DNS-over-HTTPS by default.

The AI side has several parts. A sidebar chat answers questions, summarises and talks about the page you are on, translates highlighted text and generates images. Deep Research runs multi-step, source-based research. The AI agent takes actions in the browser on your behalf, navigating pages and filling in forms toward a goal you describe. Eclipse is a local language model built into the browser, so questions, page summaries and writing help can be handled on-device without sending prompts to a server; the model is published on GitHub.

The browser is free. The cloud AI features are metered: the free tier includes limited agent runs, deep research and image generation, Plus costs $10/month ($8 billed annually) for unlimited prompts and higher limits, and Pro Unlimited costs $75/month ($60 annually) and removes the caps on agent use, search and research. Android is on a waitlist and Linux is listed as coming soon.