Sigma AI Browser review

Sigma is a Chromium-based browser from Estonia that leans on privacy and local AI. Its Eclipse model runs inside the browser so prompts stay on the device, and it adds chat with page, deep research, image generation and quick translate. The AI Agent mode lets you run OpenClaw or Hermes to open pages, click, type, fill fields and work through multi-step site tasks. In normal browsing you connect your own API key, and in Private Mode the agent can use local models instead. Sigma says user data and AI chats are end-to-end encrypted and that the browser code is open source. Pricing is low: a free plan with limited agent use, Plus at $10 a month or $8 billed annually, and Pro at $75. It ranks last because the agent setup asks more of you than rivals, and Android and Linux are not out yet.

Who it is for

Privacy-focused users who want a local model in the browser and an agent they can run on their own API key.

Price

Free plan; Plus $10 per month or $8 per month billed annually; Pro $75 per month or $60 billed annually.

$10 / mo Extend your productivity
Quoted from the vendor pricing page on November 9, 2026.

Key features

• Eclipse, a local LLM built into the browser
• AI Agent mode that opens pages, clicks, types and fills fields
• Choice of OpenClaw or Hermes agents with an API key or local models in Private Mode
• Chat with page, deep research, image generation and quick translate
• Built-in ad blocker, phishing warnings and end-to-end encrypted data

Strengths and weaknesses

• Strength: Plus is $10 a month, or $8 billed annually
• Strength: Agent can run on local models in Private Mode
• Strength: Browser code is open source
• Weakness: Standard agent use needs your own API key
• Weakness: Free plan has limited agent uses
• Weakness: Android is still on a waitlist and Linux is listed as coming soon

Key facts

• Free plan: Yes, with limited AI Agent and deep research
• Plus: $10 a month, or $8 billed annually
• Pro: $75 a month, or $60 billed annually
• Platforms: macOS, Windows, iOS; Android waitlist
• Company: Sigmabrowser OÜ, Tallinn, Estonia

Where it ranks

Sigma AI Browser is No. 9 in our Best AI Browsers verdict.