It all started with headlines claiming that Perplexity was aiming to buy Google’s Chrome browser. That bold move immediately caught my attention. How could a relatively small player even entertain such an audacious idea?
Curiosity led me to spend a weekend investigating Comet. That exploration revealed an unusual story of engineering trade-offs and surprising truths.
Every once in a while, a new browser flashes across the tech sky like a comet – bright, fast, and promising to change the way we surf the web. But behind the shine lies a story of engineering, trade-offs, and a few surprising revelations.
Meet Comet Browser, an ambitious entry into the long-running browser wars. On the surface, it offers lot of AI-powered features. But when you dig deeper, you’ll find that Comet isn’t a full browser in the traditional sense – it’s something far more unconventional.
First Impressions: A Shiny Tail
Comet Browser presents itself as a minimalist, fast, and clean browser.
But the shine is more than skin-deep:
- Tabs open fast, almost instantaneously.
- Built-in ad blocking shields you by default.
- AI-assistant and summarization features make browsing feel smarter.
Pulling Back the Curtain: What’s Really Happening
As I dug into Comet, I discovered something fascinating: Comet isn’t really a standalone browser at all.
Comet works in two main ways:
- The UI website: Acts as a smart co-pilot, providing suggestions and controlling the sidebar features.
- The extension: A hidden browser add-on that listens to commands from the website and performs actions like opening tabs or summarizing content.
The website sends structured messages to the extension, which executes them and reports the results back. Together, they create the feel of a full browser, while really running on top of Chromium with a clever helper system.
Exposing the Message Flow
The most interesting part of Comet’s design is the communication layer between the extension and the website. Here are a few examples:
OPEN_TAB,
NAV_SEARCH,
SEARCH_TABS,
...
GET_IS_DEFAULT_BROWSER,
SET_AS_DEFAULT_BROWSER
These cover tab management, ad, quick actions, system-level settings, ...
Here are simplified examples of how they work:
- OPEN_TAB
- The website sends:
OPEN_TAB(url) - Extension opens the tab and notifies the website
- SEARCH_HISTORY
- Website sends:
SEARCH_HISTORY(query) - Extension searches browser history and returns results
In effect, the extension acts as the messenger, while the website handles the logic and processing.
Architecture
Below is a unified architecture diagram showing interactions between the website UI, extension, Chromium, and AI processing.
Website(agent like UI) (interaction)
|
v
+---------------------------+
| Extension receives message |
| (open tab / search / get |
| content / ...) |
+---------------------------+
|
v
Performs action
|
v
Extension returns result
|
v
Website updates UI
|
+----------------------+
| |
v |
Website performs AI-driven actions (clicks, content processing, suggestions)
|
+----------------------+
|
+----------------------> loop back to Extension receives message
This diagram shows how the website, extension, Chromium, and AI engine work together to deliver the browser experience.
How You Can Test It Yourself
You don’t have to take my word for it. Try it out yourself:
- Open Comet Browser
- Visit: https://www.perplexity.ai/sidecar/
- Interact with the page – click buttons and use the features to see it in action.
- To check the extension, open the browser console and run:
// Check if Comet is set as the default browser
chrome.runtime.sendMessage("mcjlamohcooanphmebaiigheeeoplihb", { type: 'GET_IS_DEFAULT_BROWSER' }, console.log);
// Open a new tab via the extension
chrome.runtime.sendMessage("mcjlamohcooanphmebaiigheeeoplihb", { type: 'OPEN_TAB', payload: { url: 'https://google.com' } }, console.log);
You’ll see how the website and extension communicate in real time.
Every Comet Has a Shadow
This design comes with trade-offs:
- Complexity: Two moving parts (extension + website) increase the risk of bugs.
- Chromium dependency: Comet depends on Chromium’s APIs and updates.
- Privacy: The website may process data outside the normal browser sandbox.
- Identity: Is Comet truly a browser, or just a clever wrapper? That’s up to the users to decide.
The People Behind the Curtain
Comet’s developers are practical. Building a full browser engine from scratch is nearly impossible today. By using the website + extension approach, they deliver new ideas while staying compatible.
Users get the feel of a new browser, while developers avoid reinventing the wheel.
Will Comet Burn Out or Shine On?
Comet’s approach is unconventional and bold. If users embrace it, similar setups may follow. If not, it could fade into obscurity.
The question remains: can a smart website paired with an extension compete with Chrome, Firefox, or Brave?
Next Steps: A Dream Port
One wild idea that keeps crossing my mind – what if Comet could live inside Chrome itself?
In theory, it is possible to port the above into a Chrome, so Chrome users could tap into Comet’s smart features without switching browsers.
It’s just a dream for now – creating such an extension would take effort and time. But the concept is open for anyone curious enough to explore. If you ever get a chance to tinker with it, I’d love to see what you build.
Top comments (4)
Really interesting breakdown! I hadn’t realized Comet wasn’t a “real” browser but a smart combo of UI + extension with message passing. Super creative way to deliver a browser-like experience without building Chromium from scratch. Curious how it performs in real-world use—especially around stability and security.
Yeah, it definitely feels snappy in day-to-day browsing, but the bigger question is how it holds up over time in terms of stability and security. Since the website sits in the middle, it potentially has access to more data than a traditional browser UI would, so the trust model shifts quite a bit.
One more interesting (and slightly concerning) thing I noticed: Comet actually swaps out “Chrome” branding for “Comet” on some sites after render. That kind of behind-the-scenes substitution raises some trustability issues, at least for me. Definitely something worth watching as they evolve.
Really nice content and didn't felt bored reading
I was searching something like this on Comet
Whats your experience with the browser?enjoying?
Thanks, glad you enjoyed it!
Yeah, I’ve been using it for a while — it’s definitely fun to explore. I’m even more excited about the idea of porting this to Firefox/Chrome (and maybe other browsers too). Hope that happens soon.