Tabbit vs SigmaOS

We make Yab, the third column.facts checked Oct 9 ↓

Tabbit is a free Chromium AI browser for Mac and Windows from Lumina Lab in Singapore, with chat, an agent mode and a choice of many vendors’ models.

SigmaOS is a Mac browser on WebKit that treats tabs like a to-do list, in workspaces down the side, with an AI assistant called Airis.

The short answer

Pick Tabbit

if you want a free agent browser with a wide choice of models, Chinese ones included
if you want the same AI browser on Windows and Mac
if you want Codex or Claude Code to use your signed-in sessions through its command line

Pick SigmaOS

if you want workspaces and tabs you mark done, on a Mac
if you browse by keyboard, with single-key shortcuts
if you prefer WebKit to Chromium and want spaces

Or Yabours

if you miss Arc and want spaces, pins and folders kept, on a Mac
if you already pay for Claude or ChatGPT and want it to work in your signed-in tabs
if you want Claude Code, Codex or Cursor to drive a real browser over MCP

At a glance

Tabbit and SigmaOS, with Yab beside them for a Mac.

Tabbit vs SigmaOS
What	Tabbit	SigmaOS	Yab
Made by	Lumina Lab (LUMINALAB PTE. LTD., Singapore)	SigmaOS Inc. (London)	Serafim Korablev
Status	Updated	No release notes since February 2025	Updated
Runs on	Mac and Windows	Mac	Mac
Phone app	Only for its Chinese edition, in Chinese; tabbit.ai lists mobile as planned	None; Mac only. iOS has been on its roadmap since 2021	Not yet
Price	Free with a weekly AI allowance; Pro $30/month	Free; Personal Pro $20/month or Personal Max $30/month for more AI	Free; its AI runs on your own Claude or ChatGPT plan
AI	An agent that works in pages, on its own AI service	Chat about pages, on its own AI service	An agent that works in pages, on your Claude or ChatGPT plan
Driven by outside agents	a command line	No	MCP and a command line
Engine	Chromium	WebKit	WebKit
Tabs down the side	Yes	Yes	Yes
Spaces	Not stated	Yes	Yes
Split View	Yes	Yes	Yes
Extensions	Chrome Web Store	Chrome Web Store	Chrome Web Store
Ad blocker	Built in	Built in	Built in
Open source	No	No	No

Checked October 9, 2026 on each maker’s own pages, linked under Sources. Prices are per month, in US dollars.

Where they differ

What separates them, area by area. Where one plainly has more, it says who; where it comes down to taste, it says so.

AITabbit leads

Only Tabbit has an agent that clicks, types and finishes tasks in your pages. Tabbit chats with your tabs, files and screenshots, and its agent mode runs multi-step tasks in tab groups of its own, on GPT, Claude, Gemini, DeepSeek, Kimi, Qwen or GLM. Airis chats about the page you are on, sums it up, looks things up and translates; no agent.

Agents like Claude Code and CodexTabbit leads

Tabbit can be driven over a command line, through the Tabbit command line, with a skill for Codex, Claude Code and Cursor. SigmaOS has no MCP server or command line for outside agents.

Tabs and windowseven

Tabbit has tabs down the side, Split View and folders in the sidebar. SigmaOS has tabs down the side, spaces and Split View.

Priceeven

Tabbit: Free with a weekly AI allowance; Pro $30/month. SigmaOS: Free; Personal Pro $20/month or Personal Max $30/month for more AI.

Where it runsTabbit leads

Tabbit runs on Mac and Windows. SigmaOS runs on Mac. On a Mac, Tabbit needs macOS 13 or later and SigmaOS needs macOS 12 or later. On the phone, Tabbit: only for its Chinese edition, in Chinese; tabbit.ai lists mobile as planned. SigmaOS has no phone app: Mac only. iOS has been on its roadmap since 2021.

Engine and extensionsa matter of taste

Tabbit is built on Chromium, as Chrome is; SigmaOS on WebKit, the engine Safari uses. Both take extensions from the Chrome Web Store.

Privacyeven

Both have an ad blocker built in. Tabbit sends prompts and pages you share to the model vendor you pick, on servers in Singapore or your region; its maker says it doesn’t train on your data. SigmaOS keeps history and cookies on your Mac unless you turn on sync, stored encrypted on AWS; its privacy policy doesn’t say where Airis requests go.

UpdatesTabbit leads

Tabbit is updated as usual. SigmaOS: Still downloadable, with no public release notes since version 1.19 in February 2025.

What their pages don’t lead with

Real limits, from the makers’ own words and our own use.

Tabbit

Top models and heavy agent use need Pro at $30 a month
The free AI is a weekly allowance, larger only if Tabbit is your default browser
No Linux or phone apps yet
No MCP server documented, only its command line

SigmaOS

Mac only
No public release notes since version 1.19 in February 2025
Chrome extensions only partly work, behind its WebKit+ option
Its AI is an assistant, and regular use needs the $20 or $30 plans

Yab, honestly

Mac only: macOS 15.4 or later, no Windows, iPhone or Android
New: first released in September 2026
Its AI needs a Claude or ChatGPT plan; ChatGPT’s free plan may work with low limits
WebKit, as in Safari: a site tested only in Chrome can misbehave
Closed source

What changed lately

September 8, 2026Tabbit: Tabbit CLI lets coding agents drive the browser with your logins
August 21, 2026Tabbit: Version 1.11 dropped macOS 12; macOS 13 or later required
June 9, 2026Tabbit: Version 1.0 released after a 100-day public beta
February 4, 2025SigmaOS: Version 1.19.0, a performance update, the last release with public notes

Questions

Is Tabbit free?

Yes, with limits on its AI. Free with a weekly AI allowance; Pro $30/month.

Is SigmaOS free?

Yes, with limits on its AI. Free; Personal Pro $20/month or Personal Max $30/month for more AI.

Which has an AI agent, Tabbit or SigmaOS?

Tabbit. Tabbit chats with your tabs, files and screenshots, and its agent mode runs multi-step tasks in tab groups of its own, on GPT, Claude, Gemini, DeepSeek, Kimi, Qwen or GLM. Airis chats about the page you are on, sums it up, looks things up and translates; no agent.

Which runs on Windows, Tabbit or SigmaOS?

Tabbit does. SigmaOS runs on Mac.

Do Tabbit and SigmaOS have phone apps?

On the phone, Tabbit: only for its Chinese edition, in Chinese; tabbit.ai lists mobile as planned. SigmaOS has no phone app: Mac only. iOS has been on its roadmap since 2021.

Is SigmaOS still being updated?

Still downloadable, with no public release notes since version 1.19 in February 2025.

Is there a third option on a Mac?

Yab, Yet Another Browser, is free for the Mac: tabs down the side with spaces, folders and Split View, as in Tabbit; an agent in your signed-in tabs like Tabbit’s, on the Claude or ChatGPT plan you already pay for. Claude Code, Codex and any MCP client can drive it too. It runs on WebKit, the engine Safari uses, and takes Chrome extensions. It is Mac only, and new.

More comparisons

Tabbit vs Dia Tabbit vs Comet Tabbit vs Atlas Tabbit vs Opera Neon Tabbit vs Chrome Tabbit vs Safari Tabbit vs Edge Tabbit alternatives Yab vs Tabbit SigmaOS vs Arc SigmaOS vs Vivaldi SigmaOS vs Zen SigmaOS vs Orion SigmaOS vs Chrome SigmaOS vs Safari SigmaOS vs Edge SigmaOS alternatives Yab vs SigmaOS

Sources, read October 9, 2026. Something out of date? Write to hello@serafimlabs.io and we fix it.

Yab, Yet Another Browser.

Free for the Mac. Arc’s sidebar, your own Claude or ChatGPT as the agent, Chrome extensions on WebKit.

it’s freeDownload