Why three new browsers are suddenly worth a serious look
You probably opened this article in Chrome. That is fair. Chrome still owns roughly 65% of global desktop share. But in the past 12 months, three browsers have arrived that do something Chrome has never tried: they put a working AI assistant in the address bar, in the sidebar, and inside every tab you open.
ChatGPT Atlas launched on 21 October 2025. Perplexity Comet went free worldwide on 2 October 2025. Dia, built by the team behind Arc, became a $20-per-month commercial product on 6 August 2025 and was acquired by Atlassian for $610 million the following month. Each of these browsers ships with a different model of "what an AI browser actually does", and the differences matter enormously for how you work.
The question for any practitioner is not "should I switch?" The question is: which of these three is genuinely useful for the specific work you do, and which is hype. This article runs all three through the workflows you actually care about, and tells you which one wins, by task.
What is an AI browser, exactly?
An AI browser is a web browser with a large language model embedded as a first-class feature, not as an add-on. Instead of installing a ChatGPT extension or copy-pasting page content into a separate chat window, the assistant lives in the browser itself. It reads what is on screen, holds the context across tabs, and can take actions on pages with one prompt.
All three browsers in this comparison are built on Chromium, which means your bookmarks, extensions, and saved passwords from Chrome import in one click. The difference is what happens after the import.
The three core capabilities to evaluate are: sidebar chat (ask questions about the current page), agent mode (let the browser perform a multi-step task on your behalf), and memory (the assistant remembers what you have been doing across sessions). Each of the three browsers ranks differently on each axis.
ChatGPT Atlas: best for ChatGPT power users
Atlas is OpenAI's first browser. It is essentially the ChatGPT desktop app rebuilt around a Chromium engine, which means everything you have ever done in ChatGPT, every custom GPT, every memory, every project, every chat history, is one click away inside the browser. If you already pay for ChatGPT Plus, Atlas is the most natural upgrade path.
The strongest feature is agent mode, available to Plus, Pro, and Business subscribers. Tell it "find the cheapest direct flight from Hong Kong to Tokyo on 14 June and put it in my cart", and it opens the airline site, fills the form, picks the seat, and stops just before payment. In OpenAI's published benchmarks, Atlas completed a research brief in 47 seconds compared to Comet's 58 seconds.
The current model powering Atlas is GPT-5.5, released on 23 April 2026. OpenAI announced in March 2026 that Atlas, ChatGPT, and Codex will merge into a single desktop "superapp", which suggests Atlas is the long-term home for everything OpenAI ships next.
Where Atlas falls short: it is Mac-only as of May 2026, with no Windows or Linux build on the public roadmap. Agent mode also still requires a paid plan. And if you use Claude, Gemini, or any non-OpenAI model as your primary assistant, Atlas locks you into one vendor.
Perplexity Comet: best for research, citations, and shopping
Comet has a different personality. Perplexity built its reputation on "answers with sources", and Comet inherits that DNA. Every answer the sidebar gives you links back to the specific page, paragraph, or paper it came from. For anyone whose work involves research, fact-checking, or making a defensible case from web sources, Comet's citations alone are reason enough to install it.
Comet has been free worldwide since 2 October 2025, with no paywall on the core sidebar assistant. It runs on macOS, Windows, iOS, and Android, making it the only major AI browser available on all four platforms as of early 2026.
Free Comet users get integrated Spaces (project workspaces), Shopping (price comparison across retailers), Travel (destination research), and Finance (basic budgeting). Paid Max users ($200 per month) get the background assistant, which Perplexity describes as "a team of assistants you can manage from mission control", capable of running long tasks while you are doing other things.
In side-by-side workflow tests reported by Kahana and KDnuggets, Comet was the most reliable browser for form automation, succeeding on roughly 75% of nested form tasks where both Atlas and Dia failed. For "research and synthesise five sources into a 200-word brief", Comet remains the leader.
Where Comet falls short: agent mode is gated behind the $200-per-month Max plan, which is expensive. The browser also feels slower than Atlas on raw multi-step tasks.
Dia by The Browser Company: best for power users who like building their own shortcuts
Dia is the most opinionated of the three. The Browser Company built it from scratch around one idea: the AI assistant should be reusable, and you should be able to build your own. Dia's killer feature is Skills, which are custom prompts you create by simply describing what you want.
You can tell Dia "make me a Skill that reads a job posting and rewrites my cover letter to match it", and Dia constructs the prompt template, gives it a slash command (for example, /coverletter), and stores it in your sidebar. Next time you hit a job page, you type /coverletter and Dia runs the workflow instantly. This is the closest any browser has come to giving non-developers a real automation layer.
Dia memory is also more thoughtful than Atlas or Comet. Where the other two browsers retain blanket browsing history by default, Dia ties memory to specific tabs and Skills, which means the assistant only remembers things you have explicitly told it to remember. For practitioners working with client data or sensitive research, this matters.
Dia Pro costs $20 per month for unlimited AI chat and Skills. On 4 September 2025, Atlassian acquired The Browser Company for $610 million, signalling Dia's future as a work-focused browser inside the Atlassian suite.
Where Dia falls short: macOS 14+ with Apple Silicon only. There is a Windows waitlist but no release date. The browser is still in beta as of May 2026, which means occasional crashes and missing features.
How do I choose between Atlas, Comet, and Dia?
Pick the browser that matches what you actually do every day. The wrong choice is not Dia versus Comet versus Atlas. The wrong choice is forcing a research workflow into an agent browser, or trying to build Skills inside Atlas (you cannot).
Use this short decision matrix:
--- If your work is primarily research, citations, and fact-checking: pick Comet. The source links are non-negotiable.
--- If your work is primarily multi-step web tasks (booking, comparing, ordering, filling forms): pick Atlas. Agent mode is the most reliable.
--- If your work is primarily repetitive AI prompts that you wish you could save and re-run: pick Dia. Skills will save you hours per week.
--- If you already pay for ChatGPT Plus and most of your AI life is inside ChatGPT: pick Atlas. Your custom GPTs and project history come with you.
--- If you are on Windows or mobile: Comet is your only real option.
Try this prompt: a 3-minute test that reveals which browser fits you
Before committing to one browser as your daily driver, run this exact test in all three (or whichever two you can install today). The goal is to feel the personality of each assistant on a task you do regularly.
Try This Prompt (paste into the sidebar of each browser while on any long article):
--- "Summarise this page in 5 bullet points for a busy executive. Then list 3 follow-up questions a sceptical reader would ask, and for each question, find the answer on this page or tell me it is missing. Cite the section of the page each answer came from."
This single prompt exercises four capabilities at once: comprehension, summarisation, adversarial thinking, and source-tracking. The browser that handles all four cleanly is the one to keep. In my testing, Comet produces the cleanest citations, Atlas produces the most polished prose, and Dia produces the most concise output. There is no single "best", only the best fit for the way your brain works.
What does this mean for how you use AI at work tomorrow?
The browser is the new operating system for AI work. By the end of 2026, "open a browser tab" and "open an AI assistant" will be the same gesture. The practitioners who pick a browser early, learn its quirks, and build their workflow inside it will compound their productivity advantage week over week.
Atlas, Comet, and Dia are not competing for the same user. They are three answers to three different questions. The first question is which question matches your work. The second question is whether you have the time this week to install one, import your bookmarks, and run the 3-minute test above.
If you do not have the time, that is a signal too. It tells you your AI workflow is already overloaded, and the browser layer might be exactly the simplification you need. We understand AI. We understand you better. With UD by your side, AI doesn't feel cold.
🚀 Ready to Build an AI Workflow That Actually Saves You Hours?
Knowing which AI browser to pick is the easy part. The hard part is wiring it into a daily workflow that runs reliably, fits your team's tools, and compounds week after week. We'll walk you through every step, from tool setup, to integration with your existing apps, to building the prompt templates that make AI feel like a real teammate.
