Atlas alternatives.

Aside is an AI agent browser from a Y Combinator startup, on Chromium, for Mac and Windows. Its agent does multi-step work in the sites you are signed in to, on Aside’s own models or your ChatGPT or Claude plan.

Keeps: tabs down the side, folders in the sidebar, an AI agent and Chrome extensions.

Pick it if you want an agent for multi-step work across your signed-in sites, on Mac or Windows. The catch: The free plan has 500 AI credits a month; more is Pro at $20 or Max at $200.

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.

Keeps: tabs down the side, folders in the sidebar, an AI agent and Chrome extensions.

Pick it if you want a free agent browser with a wide choice of models, Chinese ones included. The catch: Top models and heavy agent use need Pro at $30 a month.

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.

Keeps: tabs down the side, folders in the sidebar, an AI agent and Chrome extensions.

Pick it if you want an open-source agent browser on your own AI keys or local models. The catch: No built-in model since version 0.51: connect a provider before the agent works.

Comet is Perplexity’s free Chromium browser for Mac, Windows, iPhone and Android, with Perplexity’s search and an assistant that can act on pages for you.

Keeps: folders in the sidebar, an AI agent and Chrome extensions. Misses: tabs down the side.

Pick it if you use Perplexity and want its search and agent in the browser. The catch: Free use of the assistant is limited; more agent use is Pro at $20 or Max at $200.

Opera Neon is Opera’s agent browser for Mac and Windows. Its own agents act in your live session on a $19.90 plan, and since August 2026 outside agents like Claude Code can use it free through its MCP Connector.

Keeps: an AI agent. Misses: tabs down the side, folders in the sidebar and Chrome extensions.

Pick it if you want Claude Code or another MCP client to use a real signed-in browser, free. The catch: Opera’s own agents need the $19.90 a month plan.

Chrome is Google’s browser on every desktop and phone, with Gemini built in. Its auto browse agent works in your own signed-in Chrome on a paid Google AI plan, in the US and India.

Keeps: tabs down the side (as a setting), folders in the sidebar, an AI agent and Chrome extensions.

Pick it if you live in Google’s apps and want Gemini across Gmail, Calendar and your tabs. The catch: Auto browse needs Google AI Pro ($19.99 a month) or Ultra, in the US and India only.

Edge is Microsoft’s Chromium browser on every desktop and phone, with Copilot built in. Since Copilot Mode was retired in May 2026, its agent, Browse with Copilot, comes with Microsoft 365 Premium in the US.

Keeps: tabs down the side (as a setting), folders in the sidebar, an AI agent and Chrome extensions.

Pick it if you use Microsoft 365 and want Copilot in the browser. The catch: Browse with Copilot needs Microsoft 365 Premium ($19.99 a month) and is US only.