AI Browsers Explained: What ChatGPT Atlas, Comet, and Gemini in Chrome Actually Do

What actually counts as an AI browser today

An AI browser is a regular web browser with an assistant built directly into it — not a separate app you switch to, but a sidebar or chat panel that can see the page you're looking at, answer questions about it, and in some cases act on it: filling forms, comparing options across open tabs, or clicking through a multi-step task on your behalf.

Right now there are two real ones worth knowing about:

• Perplexity Comet — a free, standalone browser you install
• Gemini in Chrome — an AI feature built into Google's existing Chrome browser, rolling out gradually by country

There was a third: ChatGPT Atlas, which OpenAI launched in October 2025 with its own agent mode for multi-step tasks. OpenAI discontinued it less than a year later, folding its features into the main ChatGPT desktop app instead, and Atlas stopped working on August 9, 2026. If you're reading an older article that recommends downloading Atlas, that advice is out of date — don't go looking for it.

That's worth pausing on for a reason beyond trivia: a major tech company launched a browser with full access to your open tabs and browsing habits, and killed it within ten months. That's a useful reminder not to over-invest trust, passwords, or sensitive accounts in any single AI browser, no matter how polished it looks on day one.

What Perplexity Comet actually does

Comet launched in July 2025 as a paid perk for Perplexity's most expensive subscribers, then went free worldwide on October 2, 2025. It's built on the same underlying engine as Chrome (Chromium), so it looks and feels familiar, with an AI sidebar added on top.

In practice, Comet can:

• Summarize a long article or webpage without you having to read the whole thing
• Compare products across multiple open tabs — prices, reviews, specs
• Manage and organize your open tabs
• Navigate through an online store and assemble items in a cart

That last one is where people usually get nervous, so it's worth being precise: Comet is designed to stop short of completing payment on its own. It can do the browsing and cart-building legwork, but it hands the final checkout step back to you for review. If you want to try it, you can download Comet from Perplexity's website and use it for browsing tasks the way you'd use a research assistant — just keep reading step 4 before you connect it to anything sensitive.

What Gemini in Chrome does, and why it might not be in your country yet

Gemini in Chrome is Google's answer built into its existing browser rather than a new one to download. It launched to all US desktop users on September 18, 2025 (it had previously been limited to paying Google AI subscribers). It can explain a confusing part of a webpage in plain language, work across your open tabs to help you compare or research something, and Google has been gradually adding small "agentic" abilities — like helping book an appointment or add items to a cart — with the final step, such as payment, left for you to confirm.

Here's the part that matters if you're reading this from Europe: as of this writing, Gemini in Chrome has not launched in the EU. It expanded from the US to Canada, India, and a handful of other countries during 2026, but EU availability is still pending, and it's widely assumed that's connected to compliance work required under EU digital regulation. Google hasn't given a firm EU launch date. If your Chrome doesn't show this feature and you're in an EU country, that's expected — it's not something broken in your settings.

The real safety risk: prompt injection

The single biggest thing to understand about any AI browser is a risk called prompt injection. It sounds technical, but the idea is simple: a webpage can contain instructions that are invisible or meaningless to you, but that the AI reads as if you had typed them yourself. It's the same basic trick as a phishing email — a message designed to fool someone into acting against their own interest — except here the target is the AI, not you directly.

This isn't a hypothetical. Between August and October 2025, security researchers at Brave and other firms disclosed several real vulnerabilities in Comet, under names like "CometJacking." In one disclosed scenario, a webpage could hide instructions — for example inside an ordinary-looking spoiler tag on a Reddit-style post — that quietly told Comet's AI to hand over sensitive information, like a one-time login code, to an attacker, all without the person browsing noticing anything unusual on screen. Perplexity has patched the specific issues that were disclosed, but the underlying weakness — a webpage being able to influence what the AI does — is a structural risk in how these agentic browsers work, not a single bug that gets fixed once and never resurfaces.

A few concrete precautions that actually help:

• Don't leave an AI browser's agent or "do this for me" mode connected to email, banking, or payment accounts unless you trust the exact page it's about to act on
• If the AI does something you didn't ask for — opens a page, fills a field, sends information — treat that as a red flag worth stopping and investigating, not a quirk to shrug off
• Keep the browser updated; vendors patch these vulnerabilities as they're found, and an outdated copy stays exposed to issues that are already fixed for everyone else
• Be extra cautious about clicking into unfamiliar or unexpected pages while an agent task is actively running in the background

Should you actually use one right now?

If you're comfortable with the idea and not in a hurry: Comet is free, real, and fine to try for research-style tasks — summarizing, comparing, browsing — as long as you follow the precautions in step 4 and keep it away from sensitive accounts. Gemini in Chrome is worth turning on once it reaches your country, since it's a feature inside a browser you likely already use rather than a new one to trust from scratch.

If you'd rather wait, that's a perfectly reasonable choice too. Nothing in a regular AI chat tool (like typing questions into ChatGPT, Gemini, or Perplexity's regular search) requires an AI browser, and this is a young, fast-moving category — the Atlas story shows that even a well-funded company can launch and cancel one within a year. There's no urgency to adopt an AI browser before it's actually useful to you.