A new browser war has begun, and it’s powered by AI. OpenAI’s Atlas and Perplexity’s Comet can now act as “agents,” booking flights or shopping for you.
But this new power comes with a huge risk. A 2025 report found Atlas fails 94.2% of anti-phishing tests, while Comet has a flaw that can steal data.
For US users, are these AI browsers the future or a security nightmare? This guide breaks down the danger and helps you choose.
Table of Contents
Key Takeaways:
- Atlas failed 94.2% of phishing tests and has “Tainted Memories” flaws; Comet has a data-stealing flaw called “CometJacking,” enabled by its Summarize button.
- Comet is available for both macOS and Windows, while Atlas is limited to macOS, making Comet the only option for the majority of PC users.
- Atlas offers excellent in-line writing help and deep personalization with “Browser Memories,” whereas Comet excels at AI-powered tab organization and free task automation.
- Due to the severe security issues, the final advice is to use both browsers as secondary tools and avoid logging into sensitive accounts like email or bank on either.
The Core Philosophy: What Are You Signing Up For?
Do not just compare features. Understand why these browsers exist first. Atlas and Comet have very different goals. This changes how you will use them.
Atlas: The ChatGPT-First Experience
Atlas comes from OpenAI, the company that made ChatGPT. It is not a traditional browser. The AI is the main product, not the browser. The browser’s purpose is to give ChatGPT context and memory for the entire web.
The browser itself is simple. The user interface is minimal and calm. This design focuses you on the AI sidebar, not on traditional browser features. OpenAI has an existing base of over 800 million ChatGPT users. Atlas is an add-on for them. It helps users rely more on their ChatGPT subscription. Atlas wins if people use ChatGPT more in their daily tasks.
Comet: The “Answer Engine” as an Assistant
Comet comes from the company Perplexity AI. Their main product is an “answer engine.” Comet’s goal is to be a “thought partner.” It is designed to accomplish tasks for you, not just chat about the web. Perplexity does not have a large user base to draw from. Therefore, the browser itself is the main product.
Comet aims to replace the old search-click-read habit. It is built on a “do-T-for-me” model. This “all-in-one” design means it has many features. Some users describe the interface as coherent. Others call it cluttered. Comet must be a complete browser to convince people to switch from Chrome. The choice is simple. Do you want a dedicated app (Comet) or an accessory for a separate AI (Atlas)?
The First Hurdle: Platform Availability
For most people, the choice is made for them.
- OpenAI Atlas: This browser is only available for macOS. OpenAI says versions for Windows, iOS, and Android are “coming soon.” As of November 2025, most PC users cannot install it.
- Perplexity Comet: This browser is available for both macOS and Windows. An Android version is in pre-registration.
For the majority of users on Windows PCs, Comet is the only option.
Setup and Familiarity
Both browsers are built on Chromium. This is the same engine that powers Google Chrome. This gives users a familiar feeling. It also means your favorite Chrome extensions will work.
The setup for both is simple. You can import your passwords, bookmarks, and browsing history from Chrome, Safari, or Firefox.
Look and Feel: Minimal vs. Feature-Dense
The designs of the two browsers are very different.
Atlas Users describe the design as minimal, elegant, and calm. The interface is clean. It focuses on the address bar and the AI sidebar. This minimalism also has negatives. Some users note a “lack of polish” and feel it is “pieced together.”
Comet Users find the Comet experience more coherent. However, it is also visually complex. Some reviewers call it “cluttered and clunky.” The interface “throws in everything,” which can overwhelm new users.
This contrast makes sense. Comet launched in July 2025. Atlas launched later in October 2025. Comet feels more like a complete product, while Atlas still feels new.
The AI Showdown: A Practical Feature Comparison
This section breaks down how the flagship AI features compare in real-world scenarios.
Category 1: The “Agent” (Doing Tasks for You)
This is the promise of “agentic” AI: automating multi-step tasks like shopping or scheduling.
- Atlas: Its “Agent Mode” is a major feature. It allows the AI to book flights or research and shop for a trip. This mode is not free. It is only available to paid ChatGPT Plus, Pro, and Business subscribers, which costs $20 per month. In performance tests, users report the agent can be slow and may stall or loop.
- Comet: The agent features are part of the core product and available in the free tier. It is designed to shop, write emails, and schedule for you. Users report it is much faster than Atlas. However, “free” does not mean “flawless.” The agent often fails on complex requests. Reviewers note it can “hallucinate” wrong dates for bookings or get stuck in loops.
Winner: Comet. Both agents are unreliable and feel like new technology. Comet’s agent, however, is free and faster. Atlas’s agent is a paid feature that is also slow and unreliable.
Category 2: Productivity & Organization
- Atlas: The key feature here is “In-line writing help.” When you select a text field in an email, Google Doc, or social media post, an icon appears. This lets you ask ChatGPT to draft, edit, or rephrase your text without leaving the window. For users who write frequent emails, this is a very practical feature.
- Comet: The key feature is “AI that organizes.” This is an AI-powered tab and “Workspace” management system. You can give it simple commands like “Organize my tabs by category.” This is a powerful tool for users who keep many tabs open.
Winner: Tie. This shows the different philosophies. Atlas helps you write better. Comet helps you organize better. The best choice depends on your primary problem.
Category 3: Research & Personalization
- Atlas: This is the browser’s main purpose. The “Browser Memories” feature allows ChatGPT to remember your habits, preferences, and visited sites. This provides a highly personalized experience. You can ask, “Open the shoe website from yesterday.” It creates a “context row” on the new tab page, making the browser feel like it knows you.
- Comet: This is Perplexity’s strength as an “answer engine.” It is excellent at summarization and provides citations for its answers. It can even summarize videos, which Atlas does not. It also features context-aware search. You can ask questions about your open tabs or ask it to “compare products.”
Winner: Atlas. Comet’s research tools are excellent. But Atlas’s “Browser Memories” is a more unique form of personalization. It learns from you passively. This is a step toward a true assistant that helps without being asked.
Comparative Feature Showdown
| Feature | ChatGPT Atlas (OpenAI) | Perplexity Comet (Perplexity AI) | Winner / Best For… |
| Platform | macOS only | macOS & Windows | Comet (by a wide margin) |
| Core AI | ChatGPT | Perplexity | Tie (User Preference) |
| Cost | Free to download | Free to download | Tie |
| Agent Mode | PAID (Requires ChatGPT Plus, $20/mo). Reported as slow. | FREE. Reported as fast, but buggy and prone to “hallucinations.” | Comet (It’s free and fast) |
| Writing Help | Excellent. “In-line writing help” in any text field. | Solid. Can draft emails and content. | Atlas (More seamless integration) |
| Organization | Basic browser features (bookmarks, etc.). | Excellent. “AI that organizes” tabs into Workspaces. | Comet (A key feature for tab-hoarders) |
| Summarization | Good. ChatGPT sidebar can summarize any page. | Excellent. Can summarize pages and videos. | Comet (Video summary is a unique plus) |
| Personalization | Excellent. “Browser Memories” remembers sites and context. | Good. Adapts to habits and can reference open tabs. | Atlas (Deeper, more passive memory) |
| Privacy Feature | Privacy controls; “memory” is opt-in. | Built-in Ad & Tracker Blocker. | Comet (A tangible, default privacy-boost) |
A Critical Warning: The Security and Privacy Trade-Offs
The “magic” of these new browsers comes with a high price. Their core design creates new dangers.
The New Danger in AI Browsers
These new browsers are “agentic.” This means the AI can act for you. It can click buttons and fill forms. This creates a new risk called “Prompt Injection.”
An attacker hides invisible instructions on a webpage. You might ask the AI to “summarize this page.” The AI reads the page, including the hidden instructions. It follows the malicious command, thinking it came from you.
This attack bypasses normal browser security. The AI is trusted, but it can be tricked. An attacker can use this to steal data from your other open tabs, like your email or bank account.
Atlas’s Alarming Security Flaws
Security researchers found several serious flaws in Atlas.
- Omnibox Vulnerability: An attacker can craft a malicious link. It looks like a normal URL but is secretly an AI command. Pasting it into the address bar executes the hidden command.
- “Tainted Memories”: A more severe attack uses a malicious link to “piggyback” on a user’s ChatGPT login. It permanently injects hidden instructions into the “Browser Memories.” This taints the AI. The infection stays, and the AI may follow the attacker’s commands in the future.
- Phishing Test: The security firm LayerX tested Atlas against 103 real-world phishing attacks. Atlas failed to stop 97 of them. This is a 94.2% failure rate. In the same test, Chrome stopped 47% and Edge stopped 53%.
Comet’s “CometJacking” Flaw
Comet has an equally severe flaw called “CometJacking.” An attacker can post a malicious comment on a site like Reddit.
A user visits the page and clicks the “Summarize” button. The AI reads the comment, including a hidden malicious prompt. This prompt instructs the AI to:
- Navigate to the user’s open Gmail tab.
- Find a one-time password (OTP) email.
- Steal the user’s credentials.
This simple attack can lead to a complete account takeover.
Privacy: Who Is Watching You?
The “magic” features of these browsers rely on watching what you do.
Atlas’s “Browser Memories” feature is, by design, a surveillance tool. Privacy advocates call it “total surveillance.” OpenAI states browsing content is not used to train its AI models, but the data is collected to build a personal profile.
Comet’s privacy policy states it collects user data, including search queries and IP addresses. Comet does offer one clear privacy benefit: it includes a built-in ad and tracker blocker. This feature blocks third-party surveillance, even as Perplexity collects its own data.
The convenience and the risk are linked. The “Summarize” button enables “CometJacking.” The “Browser Memories” enables the “Tainted Memories” attack.
The Daily-Driver Test: Performance and Usability
Speed: Browsing vs. AI
User tests show a clear trade-off between the two browsers.
Atlas provides a fast, traditional browsing experience. It loads websites at speeds similar to Google Chrome. Comet, however, feels slower for general browsing. Users report a slight lag.
The roles reverse for AI tasks. Comet completes AI requests quickly and efficiently. Atlas is slower. In one head-to-head test, Atlas took eight times longer to complete the same AI task.
The choice is simple. Atlas is a fast browser with a slow assistant. Comet is a slow browser with a fast assistant.
Resource Consumption: Battery and RAM
Both browsers use a lot of system resources. This is a problem for laptop users.
Atlas uses a large amount of power. Users report it drains laptop batteries very quickly. This matches the reputation of the ChatGPT mobile app, which is also known for high battery drain.
Comet has a different issue. It uses more RAM (memory) than Chrome.
This resource cost is high. Atlas will drain your battery. Comet will use your RAM. These problems show that neither browser is ready to replace stable options like Chrome or Safari for all-day work.
The Price of Intelligence: Free vs. Paid Tiers
These browsers make money differently than Google Chrome. They do not rely on ads.
What You Get for Free
Both browsers are free to download.
The Atlas free tier is generous. It includes the core ChatGPT integration, the AI sidebar, the “in-line writing help,” and the “Browser Memories” feature.
The Comet free tier also includes many features. You get AI search, page and video summarization, and AI tab organization. It even includes the agentic (task-doing) features. The main limit is on AI quality. Free users get a limited number of “Pro” searches, which use the best AI models.
The “Pro” Tiers
Both companies charge for their best features. The price for both is about $20 per month.
For Atlas, this $20 payment unlocks “Agent Mode.” This is the feature that automates tasks for you.
For Comet, the $20 payment unlocks the most advanced AI models, like GPT-4 and Claude 3. This gives you better answers and improves the agent’s performance.
This shows the real business model. The free browser is a way to introduce users to the AI assistant. The goal is to show the value of the AI, which encourages users to buy the $20/month subscription.
Final Verdict and Recommendations for the Average User
The Showdown at a Glance
- Atlas (OpenAI): A simple, Mac-only browser built for ChatGPT. It excels at helping you write and remembering what you see online. Its main problems are high battery drain, a slow AI agent, and extremely poor phishing protection. Security tests show it failed 94.2% of phishing attacks.
- Comet (Perplexity): A cross-platform browser built to do tasks for you. It is available on Windows, offers free task automation, and is great at organizing tabs. Its AI agent is buggy, the design can feel cluttered, and it uses a lot of RAM. It also has a severe security flaw called “CometJacking.”
Recommendation 1: For the Windows User
Your choice is simple. Comet is your only option.
Atlas is not available for Windows. You can use Comet for its free AI features and tab organization. Read the security advice below before you start.
Recommendation 2: For the Mac User
You have a real choice.
Choose Atlas if:
- You already pay for ChatGPT Plus.
- You need more help with writing emails and remembering web pages.
- You prefer a minimal, clean design.
Choose Comet if:
- You want the best free AI features.
- You want an AI to do tasks like shopping or scheduling.
- Your biggest problem is a messy browser with too many tabs.
Conclusion: Final Advice for All Users
Your decision must be based on safety. The security flaws in both browsers are serious. They are not minor bugs.
- Atlas’s 94.2% failure rate on phishing tests makes it unsafe for daily use.
- Comet’s “CometJacking” flaw means one click on a “Summarize” button could risk your email or bank account.
Here is our actionable advice: Do not use Atlas or Comet as your main, “logged-in” browser. Do not import your passwords. Do not log into your bank, email, or any sensitive account on either browser.
Treat these browsers as secondary tools. Open one when you have a specific, non-sensitive AI task. Use Comet to organize research tabs. Use Atlas to brainstorm a blog post.
When you are done, close it. Return to a stable, secure browser like Chrome, Safari, or Firefox for your everyday work. The new age of AI browsers is here, but it is not yet safe for daily use.