VebSigmaOS vs Arc
Reference archive: this page documents the original Yab browser. Features, platforms and release dates here do not describe the current Veb prototype. Veb release plans →
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.
Arc is The Browser Company’s Chromium browser for Mac and Windows, with tabs down the side, spaces, folders and Split View. Its shutdown was announced October 22, 2026: new accounts are closed, and the desktop app will stop working December 22, 2026.
Both put tabs down the side with workspaces. SigmaOS runs on WebKit and only on Macs, with no public release notes since February 2025. Arc will stop working on macOS and Windows on December 22, 2026.
Arc shutdown update: October 22, 2026. Official dates, export instructions and what to do next. Other feature facts were checked October 9, 2026.
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 already use Arc and are preparing to move before December 22, 2026
- if you need to export your Arc spaces and tabs before the desktop app stops working
- 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 Arc, with Veb beside them for a Mac.
| What | SigmaOS | Arc | Veb |
|---|---|---|---|
| Made by | SigmaOS Inc. (London) | The Browser Company (Atlassian) | Serafim Korablev |
| Status | No release notes since February 2025 | Closing December 22, 2026 | Updated |
| Runs on | Mac | Mac and Windows | Mac |
| Phone app | None; Mac only. iOS has been on its roadmap since 2021 | Arc Search on iOS and Android; AI, sign-in and sync end November 23, 2026 | Veb for iPhone, in beta on TestFlight; syncs spaces, tabs, bookmarks, history and chats |
| Price | Free; Personal Pro $20/month or Personal Max $30/month for more AI | Free for existing members until the desktop app stops working December 22, 2026 | 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 | Yes | Yes |
| Spaces | Yes | Yes | Yes |
| Split View | Yes | Yes | Yes |
| Extensions | Chrome Web Store | Chrome Web Store | Chrome Web Store |
| Ad blocker | Built in | No | Built in |
| Open source | No | No | No |
Arc’s shutdown announcement checked October 22, 2026; other features and prices checked October 9, 2026. 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. Arc Max helpers tidy tab titles and downloads, preview links and put ChatGPT in the command bar; Ask on Page was removed in August 2025, and there is no agent.
Tabs and windowsArc leads
SigmaOS has tabs down the side, spaces and Split View. Arc has tabs down the side, spaces, Split View, folders in the sidebar and tabs that sleep.
PriceArc leads
SigmaOS: Free; Personal Pro $20/month or Personal Max $30/month for more AI. Arc: Free for existing members until the desktop app stops working December 22, 2026.
Where it runsArc leads
SigmaOS runs on Mac. Arc runs on Mac and Windows. On a Mac, SigmaOS needs macOS 12 or later and Arc needs macOS 13 or later. SigmaOS has no phone app: Mac only. iOS has been on its roadmap since 2021. On the phone, Arc: Arc Search on iOS and Android; AI, sign-in and sync end November 23, 2026.
Engine and extensionsa matter of taste
SigmaOS is built on WebKit, the engine Safari uses; Arc on Chromium, as Chrome is. Both take extensions from the Chrome Web Store.
PrivacySigmaOS leads
SigmaOS has 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. Arc has no ad blocker of its own. Arc accounts will be deactivated December 22, 2026, and their personal data deleted within 30 days; export what you want to keep before then.
UpdatesSigmaOS leads
SigmaOS: Still downloadable, with no public release notes since version 1.19 in February 2025. Arc: Shutdown announced October 22, 2026: new accounts are closed, and Arc for macOS and Windows stops working December 22, 2026.
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
Arc
- New Arc accounts closed October 22, 2026
- Arc for macOS and Windows stops working December 22, 2026
- Arc Search loses AI, sign-in and sync November 23, 2026; iOS keeps basic browsing
- Arc accounts deactivate December 22, 2026; their personal data is deleted within 30 days
- Arc says Arc Search for Android will be fully deprecated and removed from Google Play and installed devices December 22, 2026
- No ad blocker of its own
Veb, honestly
- Mac only for now: macOS 15.4 or later; the iPhone app is in beta, and there is no Windows 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 22, 2026Arc: Shutdown announced: new accounts closed, mobile AI and sync end November 23, and Arc for macOS and Windows stops working December 22, 2026
- October 21, 2025Arc: Atlassian completed its purchase of The Browser Company
- August 28, 2025Arc: Ask On Page removed from Arc Max
- May 26, 2025Arc: The Browser Company stopped feature work on Arc to focus on Dia
- 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 Arc free?
Yes. Free for existing members until the desktop app stops working December 22, 2026.
Which has an AI agent, SigmaOS or Arc?
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. Arc Max helpers tidy tab titles and downloads, preview links and put ChatGPT in the command bar; Ask on Page was removed in August 2025, and there is no agent.
Which runs on Windows, SigmaOS or Arc?
Arc does. SigmaOS runs on Mac.
Do SigmaOS and Arc have phone apps?
SigmaOS has no phone app: Mac only. iOS has been on its roadmap since 2021. On the phone, Arc: Arc Search on iOS and Android; AI, sign-in and sync end November 23, 2026.
Can I move from Arc to SigmaOS?
Yes: SigmaOS’s own help says it brings in from Arc.
Is SigmaOS still being updated?
Still downloadable, with no public release notes since version 1.19 in February 2025.
Is Arc still being updated?
Shutdown announced October 22, 2026: new accounts are closed, and Arc for macOS and Windows stops working December 22, 2026.
Is there a third option on a Mac?
Veb, Very Expensive 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 new, and its iPhone app is in beta.
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
- A farewell to Arc: official shutdown timeline and export instructions (October 22, 2026)
- Letter to Arc members, 2025-05-26
- Arc for macOS release notes
- Arc for Windows release notes
- Arc macOS update feed (minimum macOS 13.0; universal binary)
- Arc unsupported devices
- Arc Max help article
- Arc import help article
- Arc ad blocking and Manifest V3
- Arc saved passwords
- Why Arc needs an account
- Arc Spaces
- Arc Split View
- Arc Folders
- Arc Search for iOS and Android
- Arc Search on the App Store (1.48.0, 2026-08-12)
- Arc Search for Android release notes
- Arc privacy policy
- Atlassian completes acquisition of The Browser Company (Business Wire)
- Arc Help: Arc Sync (what syncs, not on Android)
- Google Play: Arc Search (updated Sep 1, 2026)
- Arc Help: Arc Search for iOS release notes (iPad layout, June 20, 2024)
- TidBITS: Arc Search iPhone app now syncs Arc sidebar tabs (2024-04-29)
- Veb Manual: Bringing in from another browser
- Veb Manual: Connecting Claude or ChatGPT
- Veb Manual: Extensions
- Veb Manual: Veb’s tools over MCP
- Veb Manual: Privacy
- Mobile plans
Veb, Very Expensive Browser.
Free for the Mac. Arc’s sidebar, your own Claude or ChatGPT as the agent, Chrome extensions on WebKit.