ChatGPT Atlas vs Comet 2026: Comet Won — Atlas Is Discontinued

Pricing figures updated 6 September 2026: USD prices are converted at the current rate (1 USD ≈ 1.40 AUD, verified 5 September 2026) and shown ex-GST, replacing the retired 1.55 + GST basis. A GST-registered Australian business that supplies its ABN is not charged GST on an imported digital service; other buyers should allow ~10% on top (Methodology).

⚠ Discontinued — ChatGPT Atlas no longer exists. OpenAI announced the deprecation on 9 July 2026, and Atlas stopped working on 9 August 2026. Agentic browsing moved into the ChatGPT desktop app and a ChatGPT extension for Chrome. Bookmarks, history and open tabs did not transfer automatically, and the browser gets no further security updates. Only one side of this head-to-head is still a product you can install: Comet. We have preserved the comparison as a record of how the two matched up, not as a buying guide to both.

What an Australian reader should use instead. Comet (16/25) is the closest like-for-like swap — free on Mac, Windows, iOS and Android. Gemini in Chrome (19/25) and Copilot Mode in Edge (19/25) score higher and bill in Australian dollars. Dia (15/25) is the other standalone option. None of the four clears our Australian-fit bar outright.

Source: OpenAI Help Centre, Evolving Atlas into ChatGPT for browser-based agentic work · Wayback. Read 20 September 2026.

Winner: Comet for most Australian small businesses — it is genuinely free, it runs on Mac, Windows, iPhone and Android, and the agent that defines the category is the one you can actually use today. ChatGPT Atlas is no longer an option: OpenAI discontinued it on 9 August 2026. Comet scored 16/25 and Atlas 15/25, but the real divide was reach — Atlas stayed macOS-only for its whole life, so most Australians could never run it. Comet still carries the category's unsolved prompt-injection risk, and at Australian Fit 2/5 it is not a category Top Pick.

Last reviewed: 25 June 2026 by Adam.

If you want an AI that does not just answer questions but actually clicks, fills carts and works across tabs for you, these are the two browsers built to do it. ChatGPT Atlas is OpenAI's; Comet is Perplexity's. They make the same bet — that a lot of routine web work will soon happen through an agent inside the browser — and they share the same flaw, an agent-security problem the vendors themselves say is not solved. The difference that matters most for an Australian buyer is not the model behind the agent. It is whether you can run the thing at all, and what it costs you to do the part that makes it interesting.

At a glance

What both tools actually do

Both are standalone browsers with an AI assistant built permanently into a sidebar, not a Chrome extension. In each, the assistant can see the page you are on, summarise it, answer questions about it, and draft replies without you copying anything into a separate window. And in each, the headline feature is agent mode: you tell the AI to do a job, and it opens tabs, clicks and works across several sites to finish it — gathering links, filling a cart, comparing options, compiling a brief.

ChatGPT Atlas launched on 21 October 2025 for macOS. ChatGPT travels with you on every page, it keeps opt-in "browser memories" of what you have read so it can pick research back up later, and its agent will run multi-step tasks across sites. It rides OpenAI's frontier models, and OpenAI ships updates fast — vertical tabs, tab groups and separate profiles have all landed since launch. The catch is that, eight months on, it still only runs on a Mac.

Comet comes from Perplexity, the search company behind the "answer engine," and it launched on Windows and macOS on 9 July 2025, then Android in November 2025 and iOS in March 2026. The sidebar assistant answers with citations — Perplexity's search DNA shows — the agent clicks and acts like Atlas's, and on the top Max tier it runs background assistants: scheduled, autonomous agents that work on their own without a session open, something Atlas does not match.

Both are monitors of nothing and drivers of everything: they do not just describe the web, they act on it. That is the appeal, and the source of the risk covered below.

Pricing in Australia

The picture is the same in shape: the browser is free; the agent is not. OpenAI now quotes ChatGPT plans to Australians in AUD (read 30 September 2026); Comet's figures are our own conversions at roughly 1.40 to the US dollar ex-GST — treat them as a guide and check the figure at checkout.

ChatGPT Atlas is free to download, and the sidebar chat and browser memories work even on a free ChatGPT account. Agent mode — the reason to use Atlas over Chrome — needs a paid plan: Plus at A$30/month, Pro from A$155/month for higher limits, or Business at A$28 a seat billed annually (A$35 monthly) — OpenAI's own Australian prices. Agent mode is not available on the Free or Go tiers. OpenAI charges and itemises 10% GST to Australian customers, so a GST-registered business can claim it back cleanly — a small but real plus.

Comet is free to download and use on all four platforms, with no account needed for basic browsing, after it went free worldwide on 23 March 2026. The free tier gives you the research sidebar. The full agent rides Perplexity Pro at US$20/month (about A$28 ex-GST), and the autonomous background agents need the Max tier at US$200/month (about A$280). Perplexity charges Australian customers 10% GST and a GST-registered business can generally claim it back, but Perplexity does not itemise an AUD or GST line on its public pricing, so confirm the treatment when you subscribe.

The honest read: at the entry point they are close on price for the agent — A$30 a month for ChatGPT Plus, about A$28 for Perplexity Pro. The real cost difference is access, not dollars. To use Atlas at all you must own a Mac; to use Comet you need only a device, any device. For a Windows-and-Android Australian small business, Atlas's A$30 plan is moot, because the browser it unlocks will not run on their computer.

Where ChatGPT Atlas wins

• OpenAI's frontier models behind the agent. Atlas runs on OpenAI's best models, and the fast update cadence shows it is a serious, resourced product, not a side experiment.
• Cleaner GST handling. OpenAI itemises the 10% GST it charges Australian customers, so claiming the input tax credit is straightforward — Comet charges GST too but does not itemise it on its pricing page.
• A more candid security posture. OpenAI has been openly contrite about the agent risk, published its own hardening research, and stated plainly that prompt injection is unlikely to ever be fully solved — a more honest stance than Comet's initial brush-off of a disclosed flaw.
• The natural pick if you already live in ChatGPT. If your work already runs through ChatGPT on a Mac, Atlas slots in without learning a new assistant or a new answer style.

Where Comet wins

• It actually runs on your computer. Mac, Windows, iPhone and Android — all free. For the large share of Australian businesses on Windows and Android, this is the whole ballgame: Comet is the only one of the two they can use at all.
• Genuinely free, with no account for basic browsing. You can download it and start today without paying or signing up, and only reach for a paid plan when you want the full agent.
• A research assistant with citations. Perplexity's search heritage means sidebar answers come sourced, which makes them easier to trust than a bare summary — a real edge for research-led work.
• Scheduled background agents. On Max, you can set an autonomous agent to run on its own — a daily briefing, a recurring check — with no session open. Atlas has no equivalent.
• A slightly higher score, and an honest four stars. Comet's 16/25 edges Atlas's 15/25, driven mostly by cross-platform availability and the value of a free, useful browser.

Which to pick — decision framework

• You run Windows or Android → Comet. Atlas does not run on your machine, full stop. Comet is your only realistic option today.
• You are on a Mac and already live in ChatGPT → Atlas. It pairs with OpenAI's frontier models and slots into a ChatGPT workflow without a new assistant to learn.
• You want to try an agentic browser for nothing → Comet. Free to download on any device, no account needed, with the agent waiting behind a US$20/month plan when you want it.
• You mainly want a strong, cited research assistant → Comet. Perplexity's sourced answers in the sidebar play to its strengths before you ever pay.
• You want scheduled, autonomous background agents → Comet (Max). Atlas has no equivalent — but only buy Max if the scheduled agents genuinely save you more than US$200/month.
• Your work touches client data, money or anything regulated → neither, not yet, at least not with the agent. Both share an unsolved prompt-injection risk; keep either agent away from logged-in banking and personal-information systems.

The security story — read this before you trust either agent

This is the part you cannot skip, and it applies to both. Because an agentic browser reads web pages and acts on sites you are logged into, it is exposed to prompt injection — hidden malicious instructions buried in a page or an email that hijack the agent into doing something you never asked, like leaking data from an account you are signed into. This is not theoretical for either product.

For Atlas, security firm LayerX demonstrated a memory-injection flaw and reported the browser let through the large majority of in-the-wild phishing attacks it tested. OpenAI's own security chief has called prompt injection "a frontier, unsolved security problem" that is "unlikely to ever be fully solved," and OpenAI states in writing that its safeguards "will not stop every attack." To its credit, OpenAI has shipped hardening and built in limits — the agent cannot run code, download files or install extensions, and it pauses on sensitive sites.

For Comet, the findings are more numerous and the early response was worse. Brave showed Comet would follow instructions hidden in page content when simply asked to "summarise this page," and a follow-up smuggled instructions through text invisible to a human but readable by the browser's screenshot OCR. LayerX disclosed a data-exfiltration exploit it called CometJacking — and reported that Perplexity initially saw no security impact and marked it not applicable. Perplexity has shipped fixes since, but the pattern of repeated, demonstrated hijacks plus an initial brush-off is the single most important thing to weigh.

Both vendors say, in their own words, that human supervision is required for anything critical. Believe them. The convenience of either agent is not yet worth pointing it at sensitive, logged-in work.

The verdict

Updated 20 September 2026 — Comet wins by default, and now by survival. Atlas was switched off on 9 August 2026. Nothing below has been rewritten, because the June reasoning held: we picked Comet on reach, and reach is exactly what Atlas never got. Read the rest of this section as the record of that call.

Winner: Comet, for the typical Australian small business. It scores 16/25 to Atlas's 15/25, but the score barely matters next to the simple fact that Comet runs on the computers Australians actually use, and Atlas does not. Comet is free, it is on Mac, Windows, iPhone and Android, its cited research assistant is a real upgrade on tabbing back to a chatbot, and the agent that defines this whole category is the one you can put your hands on today. For most local businesses — on Windows and Android, where Atlas simply does not go — there is only one choice.

ChatGPT Atlas was the better fit for a narrow group: Mac users already working inside ChatGPT who wanted OpenAI's frontier models driving the agent, and who valued OpenAI's cleaner GST handling and more candid security stance. It was a genuinely capable product, held back for Australians by being locked to one platform — and OpenAI discontinued it on 9 August 2026 without ever leaving the Mac. If you want OpenAI's agentic browsing now, it lives in the ChatGPT desktop app and a ChatGPT Chrome extension.

But the bigger truth sits above both. They share an agent-security problem the vendors themselves call unsolved, neither prices or hosts data with Australia in mind, and at Australian Fit 2/5 each, neither clears our Australian Fit gate and neither can be a category Top Pick. Try whichever one runs on your machine, on low-stakes work, to see where AI browsing is heading. Just do not yet wire either agent into a business that handles client data, money or anything regulated.

Frequently asked questions

Can I still get ChatGPT Atlas?

No. OpenAI announced on 9 July 2026 that it was deprecating Atlas, and the browser stopped working on 9 August 2026. Comet is the live product in this comparison. The answers below describe both browsers as they stood in June 2026 and are kept as a record.

What is the difference between ChatGPT Atlas and Comet?

Both are standalone browsers with an AI assistant and an agent built in, doing the same job — answering about the page you are on and clicking across sites to finish tasks. The key differences: Atlas was macOS-only and ran on OpenAI's models; Comet is free on Mac, Windows, iOS and Android and runs its agent on Claude models. For most Australians, Comet won simply because Atlas never ran on Windows or Android — and OpenAI discontinued it on 9 August 2026.

Which is cheaper, Atlas or Comet?

Both browsers are free. The agent costs about the same on each: a paid ChatGPT plan (Plus at A$30/month, OpenAI's AUD price) for Atlas, or Perplexity Pro (US$20/month, ~A$28 ex-GST) for Comet. Comet has the edge on access — it is free to download with no account on any device, whereas you need a Mac just to run Atlas at all.

Are ChatGPT Atlas and Comet safe to use?

Both browsers are fine for ordinary browsing, but their agents share a real, vendor-acknowledged prompt-injection risk, where hidden instructions in a web page can hijack the agent. Outside researchers have demonstrated this against both, and more often against Comet. OpenAI says the problem is unlikely to ever be fully solved. Keep either agent away from banking and accounts holding personal data, and watch what it does.

Can I use ChatGPT Atlas on Windows?

No, and now you never will. Atlas was macOS-only for its whole life, and OpenAI discontinued it on 9 August 2026 without ever shipping the Windows, iOS or Android builds it announced in October 2025. Comet is the agentic browser you can actually run today, on any platform.

Which is better for Australians?

Comet, at 16/25 against Atlas's 15/25 — mainly because it runs on the platforms Australians use and is free to try. But both score Australian Fit 2/5 (no native AUD at review time, no local data residency, no AU support), so under our Australian Fit gate, neither could be named a category Top Pick. Use Comet: it is the only one of the two still running, after OpenAI discontinued Atlas on 9 August 2026.

Read next

• Full reviews: ChatGPT Atlas (15/25) and Comet (16/25)
• ChatGPT review: the default AI assistant, tested for Australia
• How we score AI tools — our review methodology

Sources

This comparison draws on The AI Directory Australia's underlying reviews of ChatGPT Atlas (15/25, AU Fit 2/5) and Comet (16/25, AU Fit 2/5), each scored against our five-criteria framework and verified against the vendors' own product, pricing and security pages, plus independent security research from Brave and LayerX, on 25 June 2026. Pricing, platform and security details are carried from those verified reviews. Star ratings and Top Pick eligibility follow our Australian Fit gate. USD-to-AUD estimates use ~1.40 ex-GST; OpenAI itemises GST, Perplexity charges but does not itemise it — confirm at checkout.

The Atlas discontinuation is sourced to OpenAI's own Help Centre notice, Evolving Atlas into ChatGPT for browser-based agentic work · Wayback, read 20 September 2026.

Wayback Machine snapshots queued.

The AI Directory Australia is an independent editorial publication. Read our Methodology and Affiliate Disclosure.

Synthesised from The AI Directory's verified ChatGPT Atlas and Comet reviews (25 June 2026), and updated 20 September 2026 for the Atlas discontinuation. Comet's agent still carries an unsolved prompt-injection risk — read the security section before trusting it with sensitive work.