Dia vs Comet in 2026

Dia and Comet are the two browsers people usually mean when they say "AI browser", and on paper they look alike. Both run on Chromium, both install Chrome Web Store extensions, both put an assistant beside every page, and both score 5 for AI features in our ratings. The differences are in who owns them, how much the assistant is allowed to do on its own, and what you pay for it.

Who is behind them

Dia comes from The Browser Company, the team that made Arc. Atlassian bought the company for about $610 million in a deal announced in September 2025, and has said it wants Dia to be the AI browser for work. Comet is Perplexity's browser, and it works as a front end to Perplexity's answer engine: you type a question into the address bar and get a synthesised answer with citations rather than a page of links.

An assistant for your tabs, or an agent for your errands

Dia's assistant is built around the tabs you already have open. You ask about the page in front of you, or about several pages at once, and it summarises, compares and drafts. The interface stays out of the way so the page dominates, and the basics are there: vertical tabs, split view, tab groups and sync.

Comet goes further toward doing things for you. Its assistant can operate websites on your behalf (agentic mode in our feature table), from drafting an email to filling a shopping cart, and Perplexity Max subscribers get a background assistant that keeps working while you do something else. That power comes with risks. In August 2025 Brave's security team showed that hidden text on a web page could steer Comet's assistant into leaking account details, a technique called indirect prompt injection. Perplexity fixed the specific flaws and later wrote that prompt injection remains unsolved across the industry. Separately, Amazon sued Perplexity in November 2025 over Comet's shopping agent. If you plan to hand an agent your logged-in accounts, take both seriously.

Comet also does more blocking by default, stopping ads and fingerprinting scripts out of the box. Both still score 3 for privacy, because both send page content to cloud AI services to do their work.

Price and platforms

Comet is free, and has been since October 2025. Comet Plus costs $5 a month on its own and comes included with Perplexity Pro ($20) and Max ($200).

Dia's pricing changed in August 2026. New Mac users get a 14-day trial; after that, the free plan is the browser without the AI, and the assistant needs Better Answers at $10 a month or Better Days at $100 a month. Existing users kept their free features when this launched, and Windows was not part of the change at the time.

Reach favours Comet clearly. It runs on Mac, Windows, Android and, since March 2026, iPhone. Dia is desktop only: Mac, plus a Windows 11 version that shipped in October 2026. Comet also scores 4 for extensions against Dia's 3.

Which should you choose?

Choose Dia if you work on a Mac or a Windows PC, want an assistant that reasons over your open tabs inside a calm, uncluttered browser, and like the idea of a browser built for work by the company behind Jira. Budget for a subscription if the AI is the reason you are there.

Choose Comet if you want capable AI without paying, need the same browser on your phone, research heavily, or want an agent that completes tasks for you. Just be deliberate about which accounts you let it act in.