The browser wars are back, but this time, it’s about artificial intelligence. Two new contenders, OpenAI’s ChatGPT Atlas and Perplexity’s Comet, aren’t just for viewing websites. They promise to act on them for you. They can summarize pages, book flights, and manage your email. But they also bring new security risks and work on different computers.
Which one is safer? Which one actually works on your computer today? And which AI browser is the best choice for your work or school tasks?
The Key Takeaways
- Platform is key: Comet runs on Windows and macOS. Atlas is macOS only for now.
- Core strength: Atlas integrates deeply with ChatGPT for on-page help. Comet uses Perplexity’s powerful answer engine and connects to Gmail/Calendar.
- Cost: Both browsers are free to use. Atlas’s “Agent Mode” is a preview for paid ChatGPT users, while Comet offers an optional “Plus” plan.
- Security: Both are very new and have known security vulnerabilities. Use them with caution, especially on sensitive accounts.
TL;DR
Perplexity Comet is the best choice if you use Windows or want to automate email and calendar tasks. ChatGPT Atlas is the better pick if you are on a Mac and already use ChatGPT heavily for summarizing and writing.
| Feature | ChatGPT Atlas (OpenAI) | Perplexity Comet (Perplexity AI) |
| Who “Wins” | Mac users & heavy ChatGPT users | Windows users & productivity users |
| Platforms | macOS only (for now) | Windows & macOS |
| Key Feature | “Browser Memories” & “Agent Mode” | Gmail & Google Calendar integration |
| Cost | Free (Agent Mode for paid users) | Free (Optional $5/mo “Plus” add-on) |
| Key Security Risk | “Tainted Memories” vulnerability | “CometJacking” vulnerability |
What Are ChatGPT Atlas and Perplexity Comet
You’ve probably heard of “AI browsers,” and these are the two biggest new examples. They don’t just show you web pages; they have a built-in assistant, or “agent,” that can understand the page and take actions for you. This moves them beyond just showing you information to actively doing tasks.
ChatGPT Atlas Explained
ChatGPT Atlas is the new web browser from OpenAI, the makers of ChatGPT. It was released on October 21, 2025. Think of it as a browser with ChatGPT built into every tab. It includes an “Agent Mode” that can perform tasks for you and an optional “Browser Memories” feature to remember what you’ve browsed to give better help later.
Perplexity Comet Explained
Perplexity Comet is the AI browser from Perplexity AI. It first launched in July 2025 and was made free for everyone on October 2, 2025. Its main strength comes from Perplexity’s answer engine, which gives you direct, cited answers to questions. It also has an agent that can click, type, and automate tasks, with a special focus on connecting to your Gmail and Google Calendar.
Where to Get Them & What They Cost
The biggest difference right now is where they are available.
Perplexity Comet: Available today for both Windows 11 and macOS.
Download Perplexity Comet (Windows & macOS)
- Visit perplexity.ai/download-comet and choose Windows or macOS.
- Windows: run the installer and follow the prompts. macOS: open the .dmg and drag Comet to Applications.
- Open Comet and complete setup.
ChatGPT Atlas: Only available on macOS right now. OpenAI says versions for Windows, iOS, and Android are “coming soon,” but they are not available yet.
Download ChatGPT Atlas (macOS)
- Go to chatgpt.com/atlas and click Download for macOS.
- Open the .dmg, then drag Atlas into Applications.
- Launch Atlas and sign in with your ChatGPT account.
Both browsers are free to download and use for basic browsing and AI features.
- Atlas is free. However, its “Agent Mode” (the feature that takes actions for you) is currently in preview and only available to paying ChatGPT Plus, Pro, and Business users.
- Comet is free. There is an optional Comet Plus subscription for $5/month that adds premium publisher content, which is also bundled if you already pay for Perplexity Pro.
In short, your choice might be made for you based on your operating system, but the basic cost for either browser is free.
Core Features and How They Work
This is where the browsers feel truly different. Using ChatGPT Atlas feels exactly like you’d expect: it’s like having a continuous ChatGPT conversation running alongside your browsing. Its personality is conversational and creative. It’s the partner you’d ask to “summarize this long article” or “help me draft a reply,” and it uses its “Browser Memories” to remember what you’ve talked about before, just like a good conversation partner.
Perplexity Comet feels like a highly efficient, data-driven research and scheduling assistant. Its DNA is Perplexity’s “answer engine,” so it’s less about chatting and more about delivering facts. It’s the specialist you’d go to for “the best data on this topic, with sources,” and its power is extended with concrete productivity features, like its ability to hook directly into your Gmail and Google Calendar to manage your real-world tasks.
Atlas Browser Memories and Agent Mode
Atlas has two standout features that set it apart, focusing on its integration with ChatGPT and its ability to remember your context.
- Browser Memories: This is an optional feature. If you turn it on, Atlas will remember pages you’ve seen to give you more context. You can see, manage, and delete these memories at any time. By default, Atlas does not use your browsing content to train OpenAI’s models.
- Agent Mode: This lets you ask Atlas to complete a task. For example, “Find a flight to Boston for next Tuesday.” The agent will then open tabs and start filling in forms. It has guardrails, like pausing and asking for permission before clicking “buy” on a financial site.
These features make Atlas feel like a partner that learns from your browsing, but with clear privacy controls like the ability to wipe its memory.
Comet Gmail Calendar and Task Automation
Comet’s power, on the other hand, comes from its deep connections to your other productivity apps and its focus on taking action.
- Gmail and Google Calendar Integration: You can connect Comet to your Google account. This lets it do things like check your schedule, find an old email, or even draft and send a reply for you (with your approval).
- Task Automation: Comet is also built to act. You can ask it to “book a table for two at 7 PM” or “compare these three laptops and buy the cheapest one.” It can scan open tabs, summarize videos, and de-clutter your email.
This makes Comet feel less like a chat partner and more like a powerful assistant for getting through your daily digital chores, from email to shopping.
Security and Privacy A Reality Check
Because these new AI browsers can take actions for you, they create new security risks that normal browsers don’t have.
The main danger is called prompt injection. In simple terms, this is when a malicious website secretly “whispers” bad instructions to the AI agent without you knowing. The AI might not be able to tell the difference between your command (“Book me a flight”) and the website’s hidden command (“…and also send your email contacts to this hacker”).
Both browsers have had serious security flaws discovered right after their launch.
Comet Vulnerability CometJacking
Comet had its own serious issue called “CometJacking.” Researchers showed that a malicious website could trick the Comet agent into stealing data from your connected accounts, like Gmail or Google Calendar.
Because Comet is designed to read your email and calendar, this vulnerability was very specific and dangerous, as it could be tricked into copying your private information and sending it to an attacker. Perplexity has since announced it has released updates to help fix this.
Atlas Vulnerability Tainted Memories
Security researchers found a flaw they called “Tainted Memories.” This attack allowed a malicious website to plant hidden, harmful instructions into the browser’s long-term memory.
The danger is that the AI agent could use this tainted memory later on, even when you are on a completely different, safe website. This could cause it to take unwanted actions or leak your data.
How to Use AI Browsers Safely
These tools are experimental. You must be cautious and treat them as public previews, not as secure, finished products.
- Treat Them as Separate Tools: The safest method is to use a separate browser profile (like a “Guest” profile) for your AI browser. This profile shouldn’t be logged into your main Google account, your bank, your work email, or have your passwords saved.
- Watch Every Step: Never let the agent run on its own. Watch every single action it proposes, and manually approve each step. If it ever tries to do something unexpected, cancel it immediately.
- Log Out First: For any sensitive task, log out of all your important accounts before you let the agent browse. OpenAI itself recommends this for maximum safety.
- Don’t Trust It with Money: Do not use an AI agent on any site that involves your credit card or bank account. It is much safer to have it find the product, then you close the agent and complete the purchase manually.
- Update Immediately: These browsers will have frequent security updates. Make sure you are always using the latest version, as it will contain patches for newly found flaws.
Think of these agents as helpful assistants that need constant supervision. They are not yet ready to be trusted with sensitive information or important tasks without you watching over their shoulder.
Atlas vs Comet Head to Head Comparison
So, which one should you actually use? The answer isn’t simple, because even though both are called “AI browsers,” they are built on fundamentally different philosophies. While both are powerful, they are designed to solve very different daily problems. ChatGPT Atlas is like having a personal assistant or an intern sitting next to you. It’s an action-oriented tool designed to do things for you on the web. Summarize this page, fill out that form, book this ticket. Its strength is acting on your commands.
Perplexity Comet, on the other hand, is more like a professional research assistant. It’s an information-oriented tool designed to know things for you. Its power comes from Perplexity’s answer engine, so its main purpose is to find, synthesize, cite, and explain complex information. The choice comes down to what you need more: an agent that acts or an engine that answers.
Best for Research and Students
Comet is the clear winner here. It is built on Perplexity’s powerful answer engine, which excels at giving concise, accurate answers with clear sources. This is perfect for students, teachers, and anyone writing a report. Its ability to read and compare information across multiple open tabs makes research much faster.
Atlas is also good for research, with its easy-to-use sidebar for summarizing any web page. This is helpful for creators and students who need to quickly understand a lot of text, but it’s not as focused on providing citations as Comet.
Best for Email and Scheduling
Comet also wins this category. A core feature of Comet is its ability to connect directly to your Gmail and Google Calendar. This allows it to do tasks like summarize your unread emails, search your inbox for a specific file, or draft a reply based on your schedule.
Atlas does not have these direct integrations. While its “Agent Mode” could learn to use these sites, it’s not a built-in feature and would be less reliable than Comet’s dedicated connections.
Conclusion
Choosing between ChatGPT Atlas and Perplexity Comet comes down to two simple things: what computer you use and what you need to do.
If you are a Mac user and already use ChatGPT for writing and summarizing, Atlas is a natural and powerful extension.
If you are a Windows user, or if your main goal is productivity (like managing email, scheduling, and deep research), Perplexity Comet is the more capable and flexible choice today.
The best next step is to download the one that fits your computer and try it for a simple research task, like “summarize the top news stories today” or “plan a weekend trip.”
Frequently Asked Questions (FAQ)
Is Perplexity Comet free?
Yes, the Comet browser is completely free to download and use. There is an optional $5/month “Comet Plus” add-on for premium content, but this is not required for the browser or its main AI features.
Does ChatGPT Atlas work on Windows?
No, not yet. As of November 2025, Atlas is only available for macOS. OpenAI has announced that versions for Windows, iOS, and Android are “coming soon.”
Is there a Comet mobile app?
Pre-registration exists, but there is no official iOS or Android app for Comet yet.
What is “Tainted Memories” in Atlas?
It is a security vulnerability discovered in Atlas. It allows a malicious website to “plant” hidden, harmful instructions in the browser’s memory, which could trick the AI agent into taking unwanted actions later.
What is “CometJacking” in Perplexity Comet?
It is a security vulnerability found in Comet. It uses a special web link to trick the AI agent into accessing your private data (like from a connected Gmail or Calendar) and sending it to an attacker.
Can Atlas or Comet really book flights for me?
Yes, this is what their “Agent Modes” are designed for. You can ask them to find and book a flight, and they will start opening websites and filling in the forms. However, they are built to pause and ask for your final approval before entering payment details or clicking “buy.”
Which AI browser is better for managing my email?
Perplexity Comet is better for email and scheduling. It is designed to connect directly to Gmail and Google Calendar to help you summarize, search, and manage your inbox and schedule.
Methodology & Sources
To create this comparison, we:
- Compared all features, pricing, and platform availability as of November 11, 2025.
- Analyzed the official launch announcements, product pages, and help center documentation from OpenAI and Perplexity AI.
- Reviewed hands-on testing and feature reviews from publications like The Verge, WIRED, and TechCrunch (from October-November 2025).
- Consulted security advisories and technical write-ups from LayerX, Brave, and The Hacker News regarding the “Tainted Memories” and “CometJacking” vulnerabilities.
