Design and pedigree
Dia is built by the Arc team, and the craft carries over. The interface is calm and considered in a way few AI browsers manage. If polish matters most, Dia is hard to beat.
The Dia alternative that runs on your own AI.
Dia is The Browser Company’s polished, AI-native successor to Arc, with a first-party assistant and skills. Sessionat is the open-source take: bring your own AI through MCP, keep your data local, and get auto-saved sessions on top.
At a glance
Sessionat
Dia
Engine
Chromium
Chromium (Blink)
AI control (MCP)
Built in: your Claude, Cursor
Dia’s own assistant only
Auto-saved sessions
Every 30s, named restore
No session journal
Workspaces
Arc-style sidebar
Tabs and split view
Open source
Yes (MIT)
No (closed source)
Price
Free
Free, plus Dia Pro
Compiled June 2026 from public sources. Browser features change fast, so verify before relying on a detail.
The trade-off
Dia gives you its assistant. Sessionat gives the browser to yours.
Dia comes from the team behind Arc, and it shows. It is one of the most polished AI-native browsers shipping, with a cohesive sidebar assistant and "skills" you can build to automate repeatable tasks. It launched on macOS in October 2025 with a free tier and a paid Dia Pro, and it is backed by Atlassian. If you want a first-party AI that feels designed rather than bolted on, Dia is a strong pick.
The difference is whose AI is in the driver’s seat. Dia’s assistant is Dia’s. Sessionat takes the opposite approach: it exposes the open MCP standard, so you point your own AI client (Claude Desktop, Cursor, or anything that speaks MCP) at the browser and it clicks, types, and navigates in your real session, on the accounts you are already signed into. On top of that, Sessionat is open source (MIT), keeps your data local with no telemetry, and auto-saves your sessions every 30 seconds with named restore.
The honest catch: both browsers are Chromium, and both are Mac-only today (Sessionat has Linux and Windows on the roadmap). Sessionat is not as design-polished as Dia, and it does not ship a built-in assistant of its own. If you would rather not run a separate AI client and you value a cohesive first-party experience, Dia is the smoother ride.
| Feature | Sessionat | Dia |
|---|---|---|
| Drive the browser with your own AI via MCP | ✗ | |
| Built-in first-party AI assistant | ✗ | |
| AI acts on your real logins | Its own AI | |
| Arc-style workspaces | Tabs, split view | |
| Auto-saved session journal | ✗ | |
| Local visit analytics your AI can search | ✗ | |
| Open source | ✗ | |
| Local-first, no telemetry | Cloud AI | |
| Anti-detect / fingerprint tier | Separate paid product | ✗ |
| Free to use | Free + Dia Pro |
Honest assessment
Where Dia is the better choice.
Built-in skills
Dia’s assistant ships with "skills" you can build and reuse to automate repeatable tasks, all inside the browser with nothing else to install or configure.
A cohesive first-party assistant
Dia’s AI is designed as part of the browser, so it feels integrated out of the box. Sessionat instead asks you to bring and connect your own MCP client.
Backed and resourced
Dia is backed by Atlassian, which gives it the funding and support to keep shipping. Sessionat is a smaller open-source project by comparison.
FAQ
Real questions about switching from Dia.
Is Sessionat based on Dia or Arc?
No. Sessionat is its own open-source (MIT) project built on Chromium. Dia is the closed-source successor to Arc from The Browser Company, also built on Chromium.
How is Sessionat’s AI different from Dia’s assistant?
Dia ships its own first-party assistant and skills. Sessionat does not bundle an AI. Instead it exposes the open MCP standard, so you connect your own client (Claude Desktop, Cursor, or any MCP client) and it drives your real browser on your existing logins.
Is Dia free?
Dia has a free tier and a paid Dia Pro plan with higher usage limits. Sessionat is free and open source, with a separate paid Anti-Detect product for users who need fingerprint isolation.
Does Sessionat run on Windows or Linux like, or unlike, Dia?
Both are macOS-only today. Sessionat targets Linux for mid-2026 and Windows for late 2026; Dia is macOS-only as of mid-2026.
Is Sessionat more private than Dia?
Sessionat is local-first with no telemetry: sessions and visit history stay on your Mac, and any AI access goes through the MCP client you choose. Dia’s assistant relies on cloud AI. If keeping data local matters, Sessionat is the stricter option.
Give your AI a real browser.
Free, open source, no account needed. Keep Dia installed and try Sessionat side by side.
Download Sessionat for Mac (free)