Updated April 6, 2026
- Comet outperformed Atlas on speed and task completion in head-to-head tests
- AI browsers excel at patience tasks, not reasoning or judgment
- Security vulnerabilities in Comet exposed serious risks for agentic browsing
A browser sits on a webpage, refreshing every few seconds for ten minutes straight, waiting for a single button to change color. When it finally does, the browser clicks it.
A machine performing the most tedious possible version of human attention.
Tech creator Stephen Robles built this test, among seven others, to compare OpenAI's Atlas browser against Perplexity's Comet browser. His head-to-head video runs both AI browsers through promo code hunting, Airbnb navigation, YouTube timestamp retrieval, and that peculiar button-watching exercise.
Comet won most rounds.
The interesting part is not the scorecard. It is the design philosophy each browser reveals about itself under pressure.
What Are AI Browsers?
AI browsers combine a web browser with an AI agent that can see, interpret, and interact with web pages on your behalf. Unlike traditional browser extensions, they navigate sites autonomously, filling forms, clicking buttons, and extracting information without step-by-step instructions. Atlas requires a paid ChatGPT subscription. Comet is free.
Two Theories of When AI Should Act
Atlas requires you to flip a switch. Its "Agent Mode" toggle sits in the interface, waiting for explicit permission before the browser will do anything autonomous.
The Comet browser assumes agency from the start. You ask, it acts.
This mirrors a genuine tension in AI product design. One company chose the cautious path, requiring the user to grant permission. The other assumed the machine should proceed unless the user intervenes.
"I use this every day and Comet has done this for 10 minutes, sometimes even more, just refreshing the page, looking for the button and pressing Publish when it turns purple," Robles explained during his persistent monitoring test.
In his test, Atlas declined the task.
Patience, Not Judgment
The tasks where AI browsers excel share a revealing trait. Coupon hunting. Timestamp navigation. Persistent page monitoring.
Each requires patience and repetition, not reasoning or taste.
"Both of these AI browsers can just do it right here on the website automatically," Robles noted about the promo code test. "One of the benefits of using an AI browser: it can see when a discount code is rejected and then try another one."
The Comet browser consistently finished tasks in three to five seconds where Atlas needed ten to fifteen. Independent reviewers have corroborated the speed gap. Yet speed on simple tasks may not predict performance on complex ones.
Other testers have noted that Atlas excels at persistent memory and multi-step workflows, areas Robles did not examine.
Key figure
3-5 seconds
Comet's average task completion time versus Atlas's 10-15 seconds in Robles's tests
The Questions Nobody Tested
Robles's comparison is thorough within its scope. But the scope itself reveals how early this field remains.
No privacy testing. No examination of what data these browsers collect, transmit, or retain while navigating on your behalf. No anti-bot resistance checks.
These are not criticisms of the video. They are observations about the field.
Reviewers comparing AI browsers primarily on task speed and completion rate are evaluating the technology the way early automobile reviews measured horsepower. Nobody mentioned the brakes.
While I like the design of OpenAI's Atlas, and I'll be keeping an eye on it to see what updates come, I'll still be using Comet for any AI browser needs.
Stephen Robles
What Has Happened Since
The AI browser landscape has shifted considerably since Robles posted his comparison.
Atlas added tab groups and an auto-switching search mode in January 2026. Multi-account support followed by March. OpenAI also reportedly reduced Atlas's "laziness" on repetitive tasks, the very category where it lost to Comet.
Comet expanded to iOS in March 2026, reportedly logging hundreds of thousands of downloads of the Comet browser in its first week. But the launch coincided with serious security disclosures.
Researchers at Zenity Labs found a vulnerability that allowed attackers to hijack sessions through weaponized Google Calendar invites, accessing local files and credentials. Separately, LayerX demonstrated a prompt injection attack requiring only a single URL.
Perplexity patched the Zenity vulnerability by mid-February and partnered with CrowdStrike for enterprise security.
Google entered the contest in January with Chrome Auto Browse, an agentic feature powered by Gemini. The Browser Company's Dia, acquired by Atlassian for $610 million, added integrations with Slack, Notion, and Google Calendar.
The brakes, it turns out, needed testing after all.
Sources
- Primary Source: Atlas vs Comet: Begun the AI Browser Wars Have (Stephen Robles, YouTube)
- Additional Context:
- ChatGPT Atlas Update Adds Tab Groups (MacRumors)
- Perplexity Brings AI Comet Browser to iPhone (9to5Mac)
- Perplexity Comet Browser Vulnerability Disclosure (The Register)
- CometJacking: Prompt Injection Research (LayerX Security)
- Chrome Takes on AI Browsers (TechCrunch)
- Atlassian to Buy The Browser Company for $610M (TechCrunch)
Fact Check: Claim-by-Claim Verification Verified
All 11 claims verified. One claim corrected during editing: patch timeline for Comet vulnerabilities separated (Zenity patched mid-Feb; LayerX timeline unclear). Speed figures and download counts hedged appropriately.
Commentary
- Original draft claimed both vulnerabilities patched by mid-February. Corrected: only Zenity patch is dated; LayerX timeline unclear.
- Atlas monitoring refusal hedged as single-source, version-specific observation.
- Download figure softened from "430,000" to "hundreds of thousands."
- Speed comparison (3-5s vs 10-15s) is from a single reviewer but independently corroborated by Fliki.
Fact-checked by Perplexity Sonar Pro on 2026-04-06
