YabBrowserOS vs Atlas
BrowserOS is an open-source Chromium agent browser for Mac, Windows and Linux. Its agent runs on the AI you connect: an API key, a ChatGPT or Copilot plan, Claude Code or Codex, or a local model.
ChatGPT Atlas was OpenAI’s Chromium browser for the Mac, with ChatGPT beside every page and an agent mode. OpenAI shut it down on August 9, 2026, and points people to the ChatGPT desktop app and its Chrome extension.
The short answer
- if you want an open-source agent browser on your own AI keys or local models
- if you want Claude Code, Codex or Cursor to drive a signed-in browser over MCP
- if you use Linux
- OpenAI shut Atlas down on August 9, 2026: it may not open, runs no agent tasks and gets no security updates
- 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
BrowserOS and Atlas, with Yab beside them for a Mac.
| What | BrowserOS | ChatGPT Atlas | Yab |
|---|---|---|---|
| Made by | Felafax, Inc. | OpenAI | Serafim Korablev |
| Status | Updated | Shut down August 9, 2026 | Updated |
| Runs on | Mac, Windows and Linux | Mac | Mac |
| Phone app | None; desktop only, and no Android plans as of May 2026 | None; Atlas was Mac only and shut down on Aug 9, 2026 | Not yet |
| Price | Free and open source; you pay your own AI provider | Shut down; it was free, with agent mode on paid ChatGPT plans | Free; its AI runs on your own Claude or ChatGPT plan |
| AI | An agent that works in pages, on its own AI or yours | An agent that works in pages, on its own AI service | An agent that works in pages, on your Claude or ChatGPT plan |
| Driven by outside agents | MCP and a command line | No | MCP and a command line |
| Engine | Chromium | Chromium | WebKit |
| Tabs down the side | Yes | A setting | Yes |
| Spaces | No | Not stated | Yes |
| Split View | Yes | Not stated | Yes |
| Extensions | Chrome Web Store | Chrome Web Store | Chrome Web Store |
| Ad blocker | No | Not stated | Built in |
| Open source | Yes | 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 an agent that works in your pages. BrowserOS’s agent, in the new tab and side panel, clicks, types, fills forms and pulls out data, on the AI you connect. Atlas put ChatGPT beside every page, with optional browser memories and, on paid plans, an agent mode; it no longer works.
Agents like Claude Code and CodexBrowserOS leads
BrowserOS can be driven over MCP and a command line, through a built-in MCP server with one-click setup for Claude Code, Codex and Cursor, and a command line. Atlas has no MCP server or command line for outside agents.
Tabs and windowsBrowserOS leads
BrowserOS has tabs down the side, Split View and folders in the sidebar. Atlas has tabs down the side as a setting and folders in the sidebar.
PriceBrowserOS leads
BrowserOS: Free and open source; you pay your own AI provider. Atlas: Shut down; it was free, with agent mode on paid ChatGPT plans.
Where it runsBrowserOS leads
BrowserOS runs on Mac, Windows and Linux. Atlas runs on Mac. On a Mac, Atlas needs macOS 14.2 or later. BrowserOS has no phone app: desktop only, and no Android plans as of May 2026. Atlas has no phone app: Atlas was Mac only and shut down on Aug 9, 2026.
Engine and extensionsa matter of taste
Both are built on Chromium, as Chrome is, so sites work as they do in Chrome. Both take extensions from the Chrome Web Store.
PrivacyBrowserOS leads
BrowserOS has open code. BrowserOS sends prompts and pages only to the AI you connect, or keeps them local with Ollama or LM Studio; it sends anonymous usage analytics. Atlas has no ad blocker of its own. Atlas summed up pages for browser memories and deleted the originals; training on browsing was off by default.
UpdatesBrowserOS leads
BrowserOS is updated as usual. Atlas: OpenAI shut Atlas down on August 9, 2026: it may not open, runs no agent tasks and gets no security updates.
What their pages don’t lead with
Real limits, from the makers’ own words and our own use.
BrowserOS
- No built-in model since version 0.51: connect a provider before the agent works
- Its own docs say local models are too weak for agent tasks
- Before 1.0 and changing fast: Skills and Memory were pulled in June 2026
- No phone apps
ChatGPT Atlas
- Shut down on August 9, 2026, with no more security updates
- Was Mac only, on Apple silicon
- Bookmarks, tabs and history had to be exported by hand
- Agent mode needed a paid ChatGPT plan
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 5, 2026BrowserOS: Built-in model and account sign-in removed; Chromium 155 (0.51.0)
- August 9, 2026Atlas: Atlas shut down
- July 9, 2026Atlas: OpenAI said it will sunset Atlas for the new ChatGPT desktop app
- June 17, 2026BrowserOS: Claude Code and Codex built into the agent; Skills and Memory removed (0.46.0)
- March 9, 2026BrowserOS: Vertical tabs became the default (0.42.0)
- October 21, 2025Atlas: Launched for macOS
Questions
Is BrowserOS free?
Yes. Free and open source; you pay your own AI provider.
Is ChatGPT Atlas free?
It no longer works. Shut down; it was free, with agent mode on paid ChatGPT plans.
Which has an AI agent, BrowserOS or Atlas?
Both. BrowserOS’s agent, in the new tab and side panel, clicks, types, fills forms and pulls out data, on the AI you connect. Atlas put ChatGPT beside every page, with optional browser memories and, on paid plans, an agent mode; it no longer works.
Which runs on Windows, BrowserOS or Atlas?
BrowserOS does. Atlas runs on Mac.
Do BrowserOS and Atlas have phone apps?
BrowserOS has no phone app: desktop only, and no Android plans as of May 2026. Atlas has no phone app: Atlas was Mac only and shut down on Aug 9, 2026.
Is ChatGPT Atlas shut down?
OpenAI shut Atlas down on August 9, 2026: it may not open, runs no agent tasks and gets no security updates.
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 BrowserOS; an agent in your signed-in tabs like BrowserOS’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
- BrowserOS GitHub repo (README)
- BrowserOS README (browser for humans)
- BrowserOS v0.51.0 release notes
- BrowserOS changelog
- BrowserOS docs: vertical tabs
- BrowserOS docs: ad blocking
- BrowserOS docs: getting started
- BrowserOS docs: MCP clients
- BrowserOS site FAQ
- BrowserOS privacy policy (updated 2026-03-13)
- BrowserOS site: macOS, Windows, Linux
- GitHub issue #1030 (May 25, 2026): maintainer says no plans to add Android support
- BrowserOS docs, Sync to Cloud: chats, model settings, schedules and profile sync between desktops
- OpenAI help: Evolving Atlas into ChatGPT (retirement notice)
- OpenAI help: Atlas release notes (vertical tabs, tab groups, imports, profiles)
- OpenAI help: Getting started with Atlas (macOS 14.2, Apple silicon)
- OpenAI help: Setting up Atlas (imports, password manager)
- OpenAI help: Atlas data controls and privacy
- 9to5Mac: OpenAI is discontinuing Atlas (Jul 9, 2026, James Sun quote)
- 9to5Mac: what happens when Atlas shuts down (Aug 4, 2026)
- TechRepublic: Atlas shuts down Aug 9
- TechCrunch: Atlas launch (Oct 21, 2025)
- Wikipedia: ChatGPT Atlas (Chromium, timeline)
- OpenAI Help: ChatGPT Atlas retirement
- OpenAI Help: ChatGPT release notes (Jul 9, 2026 deprecation entry)
- TechRadar: Atlas for macOS, Windows, iOS and Android ’coming soon’ (Oct 2025)
- 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.