SigmaOS
by SigmaOS
What SigmaOS is
SigmaOS is a macOS desktop browser from SigmaOS, a company founded in 2020 and headquartered in London, United Kingdom. It uses the WebKit browser engine, includes built-in ad blocking, supports browser extensions, and offers cross-device synchronization. The freemium service has a free Basic plan with unlimited workspaces, a fast ad-blocker, and limited Airis Assistant access. Personal Pro costs $20 a month, billed monthly, and includes unlimited Advanced Airis, high usage for Look it up, and high usage for Interactive Summaries. Personal Max costs $30 a month, billed monthly, adding more language models, unlimited Look it up queries, and unlimited Interactive Summaries, while also including everything in Personal Pro. SigmaOS is listed for macOS and desktop use. Users therefore choose between a no-cost tier with limited assistant access and paid plans that expand assistant queries, summaries, and model availability.
Who it suits
SigmaOS suits macOS desktop users who want a WebKit browser with ad blocking, extensions, synchronization, and integrated assistant features. The free tier can suit lighter use, while paid plans expand assistant allowances.
What it does well
- Free Basic plan is available
- Built-in ad blocking
- Supports browser extensions
- Cross-device sync is listed
- Runs on macOS desktop
What to know first
- Limited to macOS
- Basic has limited Airis Assistant access
- Paid plans start at $20 a month
- Personal Max costs $30 a month
Plans
| Plan | Billed and limits | Price |
|---|---|---|
| Basic | Unlimited workspaces · Fast ad-blocker · Limited Airis Assistant | On request |
| Personal Pro | billed monthly · Unlimited Advanced Airis · Look it up with high usage · Interactive Summaries with high usage | $20 a month |
| Personal Max | billed monthly · Everything in Personal Pro · More LLM models · Unlimited Look it up queries · Unlimited Interactive Summaries | $30 a month |
As sigmaos.com lists them, read 21 Sept 2026. The maker's own page has the final word.
Verdict
SigmaOS offers a macOS browser with built-in blocking, extension support, synchronization, and tiered assistant access. Its main choice is between the free Basic limits and monthly plans with broader assistant usage.
Facts from SigmaOS's own pages
- Browser engine
- webkit · sigmaos.com, 21 Sept 2026
- Built-in ad blocking
- Yes · sigmaos.com, 21 Sept 2026
- Cross-device sync
- Yes · sigmaos.com, 21 Sept 2026
- Extension support
- both · sigmaos.com, 21 Sept 2026
- Founded
- 2020 · sigmaos.com, 28 Sept 2026
- Free plan
- Yes · sigmaos.com, 21 Sept 2026
- Headquarters
- London, United Kingdom · sigmaos.com, 28 Sept 2026
- Supported platforms
- desktop · sigmaos.com, 21 Sept 2026
- Paid from
- 20 · sigmaos.com, 21 Sept 2026
Where SigmaOS stands on Freedom251
- Web browsers#116 of 154