Dia
A browser where you can chat with whatever's in your open tabs, summarise a page, or draft a reply in place instead of copying text into a separate AI tab.
What you'd use it for
Chatting with whatever's open in your tabs — an email, a contract, a long article — without copying it into a separate AI chat first.
- Ask a question about the tab you're looking at and get an answer that uses the page itself as context
- @-mention several open tabs at once and have Dia compare them, such as three hotel listings turned into a table
- Pull the day's calendar, inbox and key links into one view with the Morning Brief
- Search across Slack, Notion, Teams and your open tabs from a single chat
- Import bookmarks, passwords, extensions and history from Chrome, Safari, Edge or Arc when switching over
The verdict
Dia earns its place by making the browser itself the AI surface — asking about an open tab beats copying text into a separate chat window, and comparing several tabs at once is something no bolt-on extension does as cleanly. It runs on Chromium, so it costs nothing in web compatibility, but it does cost a browser switch — bookmarks, passwords and extensions get imported rather than left in place, and Windows users get a waitlist rather than a download. The Atlassian acquisition gives a reason to expect deeper ties into Jira, Confluence and Trello over time, which cuts both ways depending on how much you want in one vendor's hands. It suits someone who already lives in their browser all day and is willing to make it the default, more than someone who wants AI added to the browser they already use.
What it costs
| Tier | Price | For | Includes |
|---|---|---|---|
| Free | $0 | Anyone who wants an AI assistant woven into daily browsing rather than parked in a separate tab. | Morning Brief (calendar, inbox and key links in one view), cross-tool AI search across Slack, Notion, Teams and open tabs, work/personal profiles, split view. |
Read from Dia's own pricing page on 25 Sep 2026. Vendors change prices without notice.
What you need to start
- An Apple Silicon Mac (M1 or later) running macOS 14 or newer — Intel Macs aren't supported
- A Dia account, created during first launch, before you can start browsing
A few minutes to install and sign in on a supported Mac; the intro walkthrough and first chat happen in the same sitting.
Your first run Launch opens a short intro video and a feature walkthrough, then asks you to sign in to a Dia account before you can browse; opening a tab and clicking Chat to ask about it is the fastest way to see a real result, usually within a few minutes.
Where it breaks
macOS only at the time of this check, with Windows described as coming. Built by The Browser Company, the team behind Arc, and acquired by Atlassian in 2025.
First entry in this reference. There is no previous check to compare it against.
When not to use it
Not for Windows users yet — the browser only runs on Apple Silicon Macs, with Windows still on a beta waitlist. Not for anyone unwilling to change their default browser rather than add an extension to the one they use now, or anyone wary of one vendor's cross-tool search reaching into Slack, Notion and Teams.
Dia is what The Browser Company built after Arc — a different bet on the same underlying question, which is what a browser looks like once an AI assistant is treated as core infrastructure instead of an extension. Where Arc reorganised the interface around tabs and spaces, Dia reorganises it around asking questions of what’s already open.
The practical version of that: instead of copying a paragraph from a client email into ChatGPT to draft a reply, you ask Dia directly, with the email already in context because it’s the tab you’re looking at. Same for summarising a long article, or pulling together the morning’s calendar, inbox and key links into one view before you start the day. It’s meaningfully different from a browser extension bolted onto Chrome, because the AI has native access to the tab state rather than reading a page through a content script.
The Atlassian acquisition changes the calculus
Atlassian bought The Browser Company in 2025 for roughly $610M, which is worth naming because it shifts Dia from “well-funded startup browser” to “backed by a company that owns Jira, Confluence and Trello” — the cross-tool search feature already reaches into Slack, Notion and Teams, and an Atlassian-native integration is a reasonable thing to expect over time.
What this entry could not confirm
No pricing tier or monetisation plan appears anywhere on Dia’s public page as of this check — the product reads as entirely free at this stage, which is plausible for a browser still building its user base post-acquisition, but worth re-checking periodically since that could change.
Against the alternatives
Against ChatGPT Atlas, both are AI-native browsers solving the same underlying problem from different starting points — Dia from Arc’s tab-management heritage, Atlas from ChatGPT’s assistant heritage — and the honest test is which assistant you already trust more with your daily browsing.
Alternatives
Assistants & chatAppsMaxAI
A Chrome extension that rewrites, summarises, translates and drafts replies to whatever's on your screen — email, a webpage, a social post — without switching tabs.
Assistants & chatAppsChatGPT
OpenAI's assistant in a browser tab, a desktop app and a phone app, where you ask questions, draft text, and hand it files or spreadsheets to work through.
Assistants & chatAppsPerplexity
A research assistant that answers questions from live web sources and shows the citation for every claim, so you can click through and check it yourself.
Get Dia
Buying the tool is not the hard part.
The ebook is about what to hand over, in what order, and how you find out when it goes wrong. One payment, no subscription.