The calm, private browser for Mac.
rac brings Arc’s spaces, pinned tabs, and hiding sidebar to Helium, a fast Chromium browser that keeps your data to itself. Free and open source.
For Apple silicon and Intel Macs
rac window, Personal space, showing Ten quiet trails north of the city.
It all works. Click tabs, swipe the sidebar to change spaces, and after hiding it, point at the window’s left edge.
A space for everything.
Keep work, home, and the trip you’re planning apart, each with its own tabs and color. Give this one a name and a color.
Favorites
Your most-used sites, as tiles at the top of the sidebar. The same in every space.
Pinned tabs
They stay in one space. Close one and it resets to the page you pinned it on.
A sidebar that hides
Press ⌘S and it’s gone. Point at the left edge of the screen and it slides back over the page.
Nothing phones home.
rac is built on Helium and ungoogled-chromium, browsers made to keep your browsing to yourself. It adds no accounts, no telemetry, and no ads, and runs no servers that could hold your data.
Everything rac talks to
- Helium’s servicesAfter you agree
- Extension downloads, ad-block lists, spell check, and bangs. Run by Helium, labeled as theirs, and used only after you agree on the first-run screen.
- rac’s update feedYou can turn it off
- A file on rac’s GitHub releases, checked for new versions. You can turn it off on the About rac page.
- Your AI providerOnly with AI on
- Only if you turn AI on, and only the one you choose.
- Crash reportsOff
- rac sends none. If it ever adds them, it will ask after each crash before sending anything.
Never slower than Helium.
- Startup
- Switching tabs
- Scrolling
- Typing
These are the moments you feel. No rac feature gets to make any of them slower.
Features you turn off cost nothing: no background work, no network calls, no extra processes. Helium’s speed is the floor, not the goal.
And the small things.
Picture-in-picture, on its own
Leave a tab with a playing video, or switch to another app, and the video keeps going in a small window.
Address bar in the sidebar
One Appearance setting moves the address bar and toolbar buttons to the top of the sidebar. Try it above.
Ad blocking, built in
Helium’s own build of uBlock Origin comes with it, so there’s nothing to install.
Split view
Put tabs side by side in one window, straight from Helium.
Bangs
Type !w and a search to go straight to Wikipedia. Helium’s bangs work in the address bar.
Your old browser, brought along
The first-run tour can bring over bookmarks and history from the browser you’re leaving.
AI, only if you want it.
The assistant is off until you turn it on. Then it uses the model you choose: your own API key, a local model, or Claude Code, Codex, or Cursor if you already have them.
With your permission it can act in your tabs. You approve the sites it may use, and anything that signs in, buys, or sends always asks first. rac never sees your conversations.
Turn on the assistant
Chat about the page you’re on in a side panel. Nothing runs and nothing is sent anywhere until you turn this on and add your own provider.
Ask about this page, or ask rac to do something on it.
Open source, every line.
A browser sees everything you do, so you should be able to read its code. rac is GPL-3.0 and built in the open.
rac’s changes are a thin layer of patches on top of Helium, which is how it keeps up with every Helium and Chromium release. rac is an independent project and isn’t affiliated with Helium.
- racSpaces, pinned tabs, the sidebar, and optional AI
- HeliumPrivacy, speed, and vertical tabs
- ungoogled-chromiumChromium with Google’s services taken out
- ChromiumThe engine under all of it
Make rac your browser.
Free, for macOS 13 or later. Updates arrive on their own.
For Apple silicon and Intel Macs