An Opera alternative on the same Chromium engine
Sigma and Opera both run on Chromium and block ads, so sites and extensions work the same. The difference is that Sigma keeps the AI agent and Deep Research in the browser you already use.
Your Chrome extensions and bookmarks keep working
AI agent and Deep Research in the main browser
Built-in ad blocker and phishing warnings
Used less RAM than Opera in our 20-tab test
Why switch from Opera to Sigma
Opera packs in a lot. Sigma keeps the essentials and puts the AI tools in one browser, with no second app.
An AI agent in every tab
Describe a goal in plain words and the agent opens pages, clicks and fills forms for you. Check its work before payments and logins. Opera's agent lives in Opera Neon, a separate browser with a $19.90 monthly subscription.
Local AI that stays on your device
Eclipse is a local AI model built into Sigma. It runs on your device and works offline, so your prompts and history stay with you.
Privacy with profiles you control
Sigma blocks ads and warns you about phishing sites. Connections use DNS-over-HTTPS, and Private Profiles keep work and personal data apart, secured by a 12-word recovery phrase.
Lighter on memory
In our 20-tab test Sigma used 6.50 GB of RAM and Opera used 7.08 GB, about 9% more. See our RAM test.
With the same 20 tabs open, Sigma used 6.50 GB of RAM and Opera used 7.08 GB. Median of 5 runs on an M3 Mac with 16 GB, Sigma's own test.
Sigma
6.50 GB
Opera
7.08 GB
Private by default, with AI that stays local
Sigma blocks ads and keeps your AI prompts and profiles on your side. Learn more about Sigma Private Browser
Critical data stays local
With Eclipse your prompts and chat history stay on your device
Eclipse runs on your device and works offline, so nothing you ask is sent to a server.
Built-in ad blocker
Ads are blocked out of the box, no extension needed
Sigma blocks ads by default and warns you about phishing sites in real time. It's on from the first launch, with nothing to set up.
Private Profiles
Encrypted and secured by a 12-word recovery phrase
Keep work, personal browsing and accounts in separate spaces. Your data is encrypted and secured by a 12-word recovery phrase built on blockchain cryptography.
AI tools built into Sigma
In Sigma the AI agent, Deep Research and Eclipse live in the same browser. In Opera the agent and deep research come with Opera Neon, a separate paid browser.
AI agent
Tasks done for you
Describe a goal in plain words. Sigma's AI agent opens pages, clicks, fills forms and finishes multi-step tasks for you. Check its work before payments and logins.
Learn more about the AI agentAI chat
Ask. Research. Create
In Sigma you can ask questions, chat with any page, run Deep Research and generate images from a prompt. All of it happens in the same window, with Quick Translate one highlight away.
Learn more about Deep ResearchEclipse
Your own offline AI
Eclipse is a local AI model built into Sigma. It runs on your device, works offline and costs nothing. Ask questions, summarize pages and write drafts while your prompts stay with you.
Learn more about EclipseIs Sigma a better browser than Opera for you?
If one of these sounds like you, the switch pays off on day one.
You want AI without the cloud
Eclipse answers on your device, even offline. It's a good fit for drafts, notes and questions you'd rather keep to yourself.
You research a lot
Deep Research collects sources and groups the findings. Chat With Page summarizes any article without leaving it.
You keep separate profiles
Private Profiles keep work, personal browsing and accounts apart, each secured by a 12-word recovery phrase.
Replace Opera with Sigma in three steps
1
Download Sigma
Get the free browser for macOS or Windows, or from the App Store on iPhone. It's an Opera alternative on the same Chromium engine, so your extensions work.
2
Pick local AI
Choose Eclipse, the local model, when you want prompts to stay on your device. It works without an internet connection.
3
Browse with AI
Ask about any page, translate highlighted text with Quick Translate or hand a task to the agent. When you need sources compared, open Deep Research.
Sigma vs Opera, feature by feature
What each browser gives you out of the box, checked in October 2026.
Sigma
Opera
AI agent in the main browser
Deep Research in the main browser
Private Profiles with a recovery phrase
Unfiltered local AI model
AI agent with prompt injection defense
Opera's AI agent and deep research come with Opera Neon, a separate browser at $19.90 a month. Checked in October 2026.
Questions & Answers
If you have any questions,
reach out to us on X at @Sigma_Browser
reach out to us on X at @Sigma_Browser
Is Sigma a good alternative to Opera?
Do Chrome extensions work in Sigma?
Does Sigma use less RAM than Opera?
Does Sigma send my AI prompts to a server?
Is Sigma free?
What can I use instead of Opera?
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Get Sigma on Android
We’ll let you know when Sigma for Android launches.
