YabSigmaOS vs Dia
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.
Dia is the AI browser The Browser Company builds now instead of Arc. It is Chromium-based, for Macs with Apple silicon and, since October 2026, Windows, and its AI chats with your tabs and the tools you connect.
The short answer
- 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
- if you want the current browser from Arc’s makers, with Arc import and tabs down the side as a setting
- if you want AI that chats across your tabs, Gmail, Slack and Notion, and will pay for it
- if you want a free browser with an ad blocker and no AI
- 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
At a glance
SigmaOS and Dia, with Yab beside them for a Mac.
| What | SigmaOS | Dia | Yab |
|---|---|---|---|
| Made by | SigmaOS Inc. (London) | The Browser Company (Atlassian) | Serafim Korablev |
| Status | No release notes since February 2025 | Updated | Updated |
| Runs on | Mac | Mac and Windows | Mac |
| Phone app | None; Mac only. iOS has been on its roadmap since 2021 | None | Not yet |
| Price | Free; Personal Pro $20/month or Personal Max $30/month for more AI | Browser free; AI on Better Answers $20/month or Better Days $100/month | Free; its AI runs on your own Claude or ChatGPT plan |
| AI | Chat about 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 | No | No | MCP and a command line |
| Engine | WebKit | Chromium | WebKit |
| Tabs down the side | Yes | A setting | Yes |
| Spaces | Yes | 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.
AIa matter of taste
Both have AI to ask about pages, and neither does the clicking for you. Airis chats about the page you are on, sums it up, looks things up and translates; no agent. Dia chats with your tabs and the tools you connect, like Gmail, Slack and Notion, and drafts mail and invites; there is no documented agent that works through sites.
Tabs and windowseven
SigmaOS has tabs down the side, spaces and Split View. Dia has tabs down the side as a setting, spaces, Split View, folders in the sidebar and tabs that sleep.
PriceSigmaOS leads
SigmaOS: Free; Personal Pro $20/month or Personal Max $30/month for more AI. Dia: Browser free; AI on Better Answers $20/month or Better Days $100/month.
Where it runsDia leads
SigmaOS runs on Mac. Dia runs on Mac and Windows. On a Mac, SigmaOS needs macOS 12 or later and Dia needs macOS 14 or later. SigmaOS has no phone app: Mac only. iOS has been on its roadmap since 2021. Dia has no phone app.
Engine and extensionsa matter of taste
SigmaOS is built on WebKit, the engine Safari uses; Dia on Chromium, as Chrome is. Both take extensions from the Chrome Web Store.
Privacyeven
Both have an ad blocker built in. 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. Dia’s chat goes through its servers to Anthropic, OpenAI and Google; chats and history stay on your Mac, and content sharing is on by default, kept 30 days.
UpdatesDia leads
SigmaOS: Still downloadable, with no public release notes since version 1.19 in February 2025. Dia is updated as usual.
What their pages don’t lead with
Real limits, from the makers’ own words and our own use.
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
Dia
- AI costs $20 or $100 a month for new users; the free plan has none after a 14-day trial
- On a Mac it needs Apple silicon and macOS 14 or later
- Its AI chats and drafts, but there is no documented agent that works through sites
- No MCP server or command line for outside agents
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
- October 6, 2026Dia: Dia 1.0 for Windows released
- August 17, 2026Dia: Paid AI plans started rolling out to new Mac users
- October 21, 2025Dia: Atlassian completed its acquisition of The Browser Company
- February 4, 2025SigmaOS: Version 1.19.0, a performance update, the last release with public notes
Questions
Is SigmaOS free?
Yes, with limits on its AI. Free; Personal Pro $20/month or Personal Max $30/month for more AI.
Is Dia free?
The browser is; its AI isn’t. Browser free; AI on Better Answers $20/month or Better Days $100/month.
Which has an AI agent, SigmaOS or Dia?
Neither has an agent that does tasks in your pages. Airis chats about the page you are on, sums it up, looks things up and translates; no agent. Dia chats with your tabs and the tools you connect, like Gmail, Slack and Notion, and drafts mail and invites; there is no documented agent that works through sites.
Which runs on Windows, SigmaOS or Dia?
Dia does. SigmaOS runs on Mac.
Do SigmaOS and Dia have phone apps?
SigmaOS has no phone app: Mac only. iOS has been on its roadmap since 2021. Dia has no phone app.
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 SigmaOS; an agent that works in your signed-in tabs, 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
- SigmaOS home page
- SigmaOS upgrade (plans)
- SigmaOS download (macOS only)
- SigmaOS update feed (appcast)
- SigmaOS 1.19.0 update notes
- SigmaOS 1.17.0 update notes (password manager)
- SigmaOS common questions
- SigmaOS docs: ad blockers and WebKit+
- SigmaOS docs: migrating from Arc
- SigmaOS privacy policy
- TechCrunch: SigmaOS turns to AI features for monetization (2024-03-26)
- Launch HN (Aug 16, 2021): founder says iOS and iPadOS are on the roadmap
- Dia plans and pricing FAQ
- Dia home page (macOS and Windows, ad and tracker blocking)
- Dia changelog (Chromium M155, Windows 1.0, tab sleep, sidebar or top tabs, AppleScript, memory retired)
- Dia release notes 1.52.0 (Oct 8, 2026)
- Dia download FAQ (import from Chrome, Safari, Edge, Arc)
- Dia security (AI providers, retention, local storage)
- MacRumors: Dia generally available, macOS 14 and Apple silicon
- PiunikaWeb: Dia $20 and $100 plans (Aug 18, 2026)
- Atlassian completes acquisition (Oct 21, 2025)
- Dia home page: ’Available for macOS and Windows’
- PiunikaWeb: Dia ’iPhone Tabs’ menu spotted, no public app (2026-08-25)
- Yab Manual: Bringing in from another browser
- Yab Manual: Connecting Claude or ChatGPT
- Yab Manual: Extensions
- Yab Manual: Yab’s tools over MCP
- Yab Manual: Privacy
Yab, Yet Another Browser.
Free for the Mac. Arc’s sidebar, your own Claude or ChatGPT as the agent, Chrome extensions on WebKit.