Zen Browser 1.22b Ships Cross-Device Space Sync, Squircle UI, and Firefox 155 Security Patches
The privacy-focused Firefox fork closes its biggest gap with Arc as the small team keeps shipping weekly updates.
Zen Browser 1.22b is live. The release lands under build date 2026-09-04 and finally brings cross-device sync for Spaces, Folders, and active Tabs. Everything runs through Mozilla accounts, which means your isolated workspaces now live outside your local hard drive. The update is built on Firefox 155.0.1, arrives with a redesigned chrome, and patches 42 security vulnerabilities pulled straight from Mozilla's upstream advisory.
For the past year, Zen's workspaces were strictly local. You could juggle dozens of isolated contexts on your main machine, but log into a different computer and they vanished. That limitation made it hard to pitch Zen as a primary browser, especially with Arc dominating the workspace-organization space. Today's update flips that script. Enable the toggle under Settings > Sync, and your Spaces will merge with your cloud data on first launch. You can turn it off at any time, but expect a prompt to handle the merge logic.
What Actually Made It Into the Box
The squircle redesign isn't just cosmetic. The browser's own chrome now uses softer rounded corners, and the sidebar font got a noticeable bump. New users land in a guided onboarding flow that walks them through Spaces, Boosts, Live Folders, and the rest of the stack. If you've ever waited through a heavy animation just to spin up a new Space, the drop in wait time is immediate.
I spent about forty minutes poking around the beta in early August, and the animation lag on space creation felt genuinely noticeable even then. It's smoothed out now. Container ordering in the settings menu is finally drag-and-drop, and it actually sticks wherever you place it.
Live folders for GitHub issues were completely broken after the platform's UI update, and that's now fixed. Linux users won't have their systems held awake after long browsing sessions, keyboard navigation on complex pages behaves itself again, and internet radio streams won't cut out the moment you Alt-Tab away. Keep in mind that captive portal detection is now hitting firefox-portal-detection.com instead of the old Firefox domain, so network admins using strict allowlists should update their rules.
The Security Situation
Firefox 155 dropped yesterday, and Mozilla bundled 42 vulnerability fixes across the board. Zen pulls in every patch without waiting for a separate fork cycle. The advisory covers privilege escalation on Android, use-after-free bugs in JavaScript and WebGPU, sandbox escapes in DOM navigation, and several site isolation leaks. Most of the high-severity items hit components like audio/video decoding, layout grid boundaries, and core HTML parsing. Not cheap to ignore when you're syncing workspaces across machines.
The release ships native builds for Linux x86-64, Linux aarch64, macOS, and Windows x86-64 plus ARM64. Installer sizes range from roughly 92 MB to 159 MB depending on your platform. Head here to grab the full download table with SHA-256 hashes if you want to verify before installing.
If you've been tracking the repository, you know the team barely blinks. Through August and early September, they've shipped eight major revisions. Each one layers a new capability on top of performance tweaks. Boosts dropped in May, Live Folders in February, Space Routing last month. The entire effort runs on a skeleton crew. Mauro V. leads development, Jan Heres handles macOS builds, and a handful of contributors round out the split views, code signing, and AUR maintenance. Donations and sponsorships from Crowdin, Tuta, and BlackSmith keep the lights on.
It's a steep ask for a project that relies on community funding to match the polish of Arc's workspace sync, but the squircle redesign and onboarding flow prove Zen isn't just slapping features on Firefox. However, at the same time, the lack of desktop app-level sync for passwords and cookies compared to Chrome remains a gap for full primary-browser replacement. Still, if you're looking for a calmer, privacy-first browser that treats workspaces like a first-class citizen, this is the best Zen has shipped in 2026.
Download Zen 1.22b from GitHub. Report issues on the repository, or hop into the Discord and Reddit channels if you want to ping the team directly.
