Comet is Perplexity's AI browser, built on Chromium, with an assistant in the sidebar that reads pages, summarizes email and carries out tasks such as shopping inside the user's logged-in sessions. It launched on Jul 9, 2025 for Perplexity Max subscribers at $200 a month, became a free download for everyone on Oct 2, 2025 and now runs on Windows, macOS, Android and iOS. Perplexity said millions of people had joined the waitlist before it went free.
Comet is also the agent at the center of the first big lawsuit over AI shopping. Amazon blocked it on Aug 19, 2025, alleging Perplexity shipped an update within 24 hours to get around the block, and sued on Nov 4, 2025, arguing in its complaint that Comet sends Chrome's user agent with no unique identifier. A preliminary injunction kept Perplexity's agents out of Amazon's password-protected systems from Mar 9, 2026 until the Ninth Circuit vacated it on Aug 4, 2026, holding that the user, not Perplexity, is the one accessing the site. Amazon's other claims are still open, and site owners have been asking how to tell Comet's agent apart from its user ever since.
How Perplexity Comet shows up on your site
Comet runs on the user's own device and talks to your site directly. According to the Ninth Circuit record, screenshots of what the browser shows go to Perplexity's servers, which send back the next navigation steps, while Perplexity's servers never contact the site themselves. Inside the browser, the agent runs through a hidden internal extension, and during agent actions that extension's files, such as overlay.js, can show up in the page. Every request still comes from the person's own browser, cookies and IP, with Chrome's user agent and Client Hints. Perplexity publishes IP lists for its PerplexityBot and Perplexity-User fetchers, but those cover different traffic and say nothing about Comet.
| Check | What Comet does |
|---|---|
| User agent | Chrome's, with Chrome Client Hints and no unique identifier |
| Web Bot Auth signature | None |
| IP ranges | None, traffic uses the user's own IP |
| robots.txt | Not applicable to a browser |
Why Perplexity Comet is hard to detect
Comet is a real Chromium browser on a real customer's device, so it passes the checks that catch most bots. The IP is residential, the cookies belong to an account you already trust and the user agent says Chrome, which Amazon's complaint makes central to its case. Any rule that relies on a declared identity has nothing to match.
What remains is how the assistant behaves when it takes over. Researchers at UC Davis found in their FP-Agent study that Comet pastes text into fields instead of typing, and on Windows it sends Ctrl+A followed by a paste with key holds of about 3 milliseconds. Its turns also show very even timing, dense bursts of actions and a pointer that jumps straight to targets. These traits, and the extension's file names, can change in any Comet update, and the person can take over at any moment, so a single session often mixes human and agent activity.
How Verisoul detects Perplexity Comet
Verisoul does not name Comet yet, because Comet gives us no declared identity or signature to verify, and we only name an agent when we can prove which one it is. Instead, Verisoul reads the automation that Comet's internal extension leaves in the browser and the machine-like input in the session, and those raise the bot score on the session while the agent field stays empty.
"agent": nullbot_scoreis a number from 0 to 1 that rises as the session looks automated, and 0.97 means the input and page flow look like softwareagentisnullbecause Comet does not declare or sign its identity, so Verisoul does not attach a name- The network looks like a normal visitor, since Comet uses the user's own IP, which is why the score leans on device and behavior
When Verisoul can name Comet, it will get its own entry in Agent Atlas, and the AI agent detection docs explain how bot score and the agent field work together.
- 01User asks Comet to buy something
- 02Comet opens your site in their browser
- 03Perplexity's servers plan each click
- 04Your site sees Chrome on a home IP
How to detect Perplexity Comet step by step
- Add the Verisoul SDK to login, checkout and payout pages, following the AI agent detection docs
- Watch for sessions on known accounts where
bot_scoreis high andagentis null, which is where Comet and similar browsers land - Write rules that review card additions, payout changes and repeated payment attempts when that pattern appears
- Keep browsing and normal checkout open, and check the review queue weekly to tune the score threshold
Should you block Perplexity Comet?
In most cases, no. Comet usually acts for a real, logged-in customer finishing an errand, and the Ninth Circuit's ruling treats that customer as the one using your site. Browsing, search and ordinary checkout can stay open.
The steps to watch are the ones where money moves. A high bot score on a session that adds several cards, retries payments or changes payout details is worth a review whatever browser it came from, and sign-up is worth the same care because an automated browser on a residential IP can create accounts that look like real people.