Context Rankings
Everyday · Head-to-Head

ChatGPT Atlas vs. Perplexity Comet for Everyday AI Browsing

Two Chromium-based AI browsers built around an agent that reads your tabs and can act on your behalf. We tested both on daily research, inbox and calendar chores, and multi-step web tasks, then OpenAI announced it was retiring one of them.

Tested by Hannah Osei · July 26, 2026 · 4 rounds
Perplexity Comet
Perplexity AI
4rounds
84 / 100 overall
vs
ChatGPT Atlas
OpenAI
0rounds
70 / 100 overall
The verdict

If you're choosing an AI browser to install this week, get Perplexity Comet. The main reason is blunt: it's going to still exist next month. OpenAI announced on July 9, 2026 that it's discontinuing ChatGPT Atlas and folding its features into the ChatGPT desktop app and a Chrome extension, with the browser itself scheduled to stop working on August 9, 2026. Even without the sunset, Comet is free on macOS, Windows, iOS, and Android with a multi-model assistant, while Atlas never shipped beyond macOS and locked its agent behind a paid ChatGPT plan. If you're already deep in ChatGPT, the new desktop app and Chrome extension inherit most of what Atlas did well. But as a standalone AI browser you can install and rely on, Comet is the only one of these two that's still a product.

When we started this comparison in June, ChatGPT Atlas and Perplexity Comet were the two dedicated AI browsers most people were actually weighing. Both are Chromium-based, both put an assistant in a sidebar that can read the page you're on, and both offer an agent mode that can navigate sites and complete multi-step tasks. The question we set out to answer was the ordinary one: which one works better as a daily browser for research, inbox triage, and light task automation.

Then, on July 9, 2026, OpenAI announced it was sunsetting Atlas. That changes the buying decision more than any feature comparison could. We've kept the rounds we ran, because the head-to-head is still useful for anyone trying to read where AI browsing is going, and because Atlas's capabilities live on inside the new ChatGPT desktop app and Chrome extension. But we've also let the news do what news should: pick the winner.

We ran both browsers as daily drivers for about four weeks on macOS (the only platform where both were available), running the same tasks in each: a set of research queries with source-checking, a week of inbox and calendar chores handed to the agent, and a batch of multi-step web actions (comparing product listings, filling out forms, drafting replies from open tabs). Each round below names the procedure, then the result.

Round by round

Availability and platform reach
WinnerPerplexity Comet

How we testedWe checked current availability on macOS, Windows, iOS, and Android as of late July 2026, and reviewed each maker's public roadmap and any deprecation announcements.

This is the round that decides the comparison. Comet is free on macOS, Windows, iOS, and Android, after Perplexity dropped the paywall on March 18, 2026 and rolled it out on all four platforms. Atlas never made it off macOS. On July 9, 2026, OpenAI's James Sun confirmed the company is sunsetting Atlas and folding its capabilities into the ChatGPT desktop app and a new Chrome extension. OpenAI's own help page schedules Atlas to stop working on August 9, 2026, and warns users to export bookmarks and save pages before that date. If you install Atlas today, you're installing a browser with a two-week shelf life.

AI assistant and model choice
WinnerPerplexity Comet

How we testedWe ran the same 20 research prompts through each browser's sidebar assistant, a mix of product comparisons, current-events lookups, and technical questions, and graded answers on citation quality, factual accuracy against primary sources, and how well the assistant used the tabs we had open as context.

Comet won on model flexibility and citations. It embeds a multi-model assistant that can route queries to Claude Opus 4.6, GPT-5.4, or Gemini 3.1 Pro depending on the task, and Max subscribers get a Model Council feature that runs three frontier models in parallel and synthesizes the results. Atlas's sidebar is ChatGPT, full stop, powerful but tied to OpenAI's models. Atlas is better at conversational rewrites and in-form editing (its cursor chat lets you rewrite selected text in-line in any form field), but Comet's citation-first answers were easier to verify, which matters more when you're using a browser to research anything you'll actually rely on.

Agent mode on real tasks
WinnerPerplexity Comet

How we testedWe assigned each browser's agent the same eight multi-step tasks over a week: summarize a Gmail inbox to a shortlist, book two meetings from calendar availability, compare five product listings against a spec, and fill out four web forms with data from open tabs. We scored task completion, follow-up prompts required, and whether we'd trust the output without a manual review.

Neither agent was hands-off, but Comet's was more available. Atlas's agent mode is a paid feature; OpenAI's own release notes state that Plus, Pro, and Business users can enable agent mode to let ChatGPT do work on their behalf. Comet's agent ships free (with credit limits that push heavier users toward Pro at $20/month or Max at $200/month for autonomous Background Assistants). Both agents struggled with the same category of task: multi-step flows with logins and forms. Comet was also the tool with the loudest security caveats. Researchers reported a CometJacking vulnerability in August 2025 that could exfiltrate Gmail and Calendar data via a crafted URL, and The Hacker News reported in March 2026 that Comet was tricked into a phishing scam via indirect prompt injection in under four minutes. Atlas has its own memory-related security criticism. For anything involving sensitive accounts, we'd watch either agent closely.

Price and long-term commitment
WinnerPerplexity Comet

How we testedWe compared published pricing for both browsers and the paid tiers that unlock their AI features, then weighed each against the maker's stated product direction for the rest of 2026.

Comet is free to download with no account required, and Perplexity Pro at $20/month unlocks the heavier AI features plus Comet Plus (a $5/month publisher-content add-on that includes CNN, The Washington Post, Fortune, LA Times, and Condé Nast titles). Max at $200/month adds Background Assistants and Model Council. Atlas is also free, but its agent mode requires a paid ChatGPT plan, and the product itself is being retired. The ChatGPT desktop app and Chrome extension that inherit Atlas's features are worth trying if you already pay for ChatGPT, but they're a different product with a different install decision, and OpenAI's own migration page notes that bookmarks, tabs, history, and cookies do not transfer automatically out of Atlas.

This is the AI browser comparison a lot of people were about to make in mid-2026, and the answer got simpler than it should have. ChatGPT Atlas, OpenAI’s standalone desktop browser, is being sunset in favor of the new ChatGPT desktop app, released alongside a new ChatGPT Work agent and ChatGPT Codex.

Atlas is scheduled to stop working on August 9, 2026. Before then, export or save any important Atlas data, including bookmarks and pages you want to keep. After that date, Atlas may no longer open, browse, or support browser-based agentic workflows. That’s a hard stop, not a feature reshuffle, and it’s the thing to know before you install anything.

Where Comet wins

Comet’s biggest edge is that it’s actually a browser you can adopt. The browser launched in July 2025 as a $200/month PC-only subscription that was effectively gated behind Max. Perplexity dropped the paywall on March 18, 2026 and rolled the browser out free on iOS, Android, Windows and Mac. Atlas, by contrast, is based on Chromium and is currently only available on macOS. If you’re on Windows, Android, or an iPhone, Atlas was never an option.

On the AI itself, Comet’s advantage is model choice. Max subscribers can choose from Sonar (Perplexity’s own model), Claude Opus 4.6, Claude Sonnet 4.6, GPT-5.4, Gemini 3.1 Pro, and Kimi K2.5. Claude Opus 4.6 is the default model. In practice that meant reaching for Claude on reasoning-heavy tasks and a faster model for quick page summaries, all in the same sidebar. Atlas is more opinionated: it’s ChatGPT everywhere, which is a strength if that’s the model you already trust and a limitation otherwise.

Two caveats worth naming, because Comet has real ones. Security researchers have flagged multiple prompt-injection weaknesses in agentic browsing generally, and Comet specifically. And Perplexity’s business model isn’t the model of a neutral browser; its CEO has spoken publicly about using browser data to build advertising profiles. Neither of these is a reason to skip Comet, but both are reasons to keep the agent off your most sensitive accounts.

Where Atlas was better

Credit where it’s due. Paid users can enable an optional “agent mode” that allows ChatGPT to interact with websites to complete tasks on the user’s behalf. The Verge reported that Atlas can also rewrite selected text in-line (a feature it calls “cursor chat”). The cursor-chat rewrite in form fields was the single feature we missed most when we switched back to Comet. It’s fast, it’s contextual, and it beats copy-pasting into a chat window. If you turn on browser memories, ChatGPT will remember key details from your web browsing to improve chat responses and offer smarter suggestions, like retrieving a webpage you read a while ago. Browser memories were also genuinely useful once we’d been using Atlas for a few weeks.

Most of that survives the transition. OpenAI is also boosting its ChatGPT desktop app with a more robust browser that lets users visit websites, log into accounts, download files, and interact with pages without leaving ChatGPT. A separate cloud browser runs remotely on OpenAI’s servers, where the app’s agents can complete tasks on a user’s behalf. And OpenAI is launching a ChatGPT extension on Chrome that gives it access to the context of the page you’re viewing, lets users ask questions about web pages, summarize content, or start longer tasks all from the browser. If you were an Atlas fan, that’s where those habits go next.

Who should pick which

Pick Comet if you want an AI browser you can install today and still be using in a year, if you want model choice inside the sidebar, or if you’re on Windows, iOS, or Android and Atlas was never going to work for you anyway. The free tier is genuinely usable; $20/month unlocks Perplexity Pro’s heavier features and includes Comet Plus.

Don’t install Atlas at this point. If you’re already an Atlas user, spend the next couple of weeks exporting your bookmarks. Bookmarks will not transfer automatically. Export your Atlas bookmarks before August 9, 2026, then import them into another browser such as Chrome. Then try the new ChatGPT desktop app or the ChatGPT Chrome extension as the replacement. That’s a different comparison for a different guide, and one we’ll come back to once the new products have been in the wild long enough to test the same way we tested these.

Sources