Arc for Chrome

A local-first sidebar for vertical tabs, Spaces, folders, saved sites, Chrome history, and recently closed tabs.

No accounts · No analytics · No ads · No data sent to the developer

Start here — no Terminal required

Install Arc for Chrome from the Chrome Web Store.
Select Chrome’s extensions button, pin Arc for Chrome, then open it.
Choose Start fresh, Move from Arc, or Restore a backup. The setup screen shows only the steps for your choice.
For the intended left layout, select Open Chrome appearance, set Tab position to Vertical, and Chrome panels to Left.
Select Finish setup. Create Spaces with +; drag tabs onto a Space dot to move them.

That is enough for the normal sidebar. The macOS compact-layout helper is optional and can be installed later from Setup and privacy.

Optional macOS helpers

These helpers run only on your Mac. They have no updater, analytics, network connection, or publisher server. Arc for Chrome’s core sidebar works without them.

Arc migration helper Creates one local .arcsidebar file containing Arc Spaces, folders, saved tabs, Archive, locally available history, and cached icons. Compact layout helper Makes the macOS window offset and Chrome theme matching reliable. Requires local Accessibility permission for /usr/bin/osascript.

SHA-256 checksums

Move your setup

From another Arc for Chrome profile

Open Setup and privacy in the source profile.
Select Export sidebar backup.
In the new profile, select Sidebar backup and choose the downloaded JSON file.

From Arc on macOS

Download and unzip the Arc migration helper.
Open Arc once and wait for its sidebar to finish loading.
Open Prepare Arc Migration.command once. If macOS says it cannot verify the file or offers to move it to Trash, dismiss the warning. Open System Settings → Privacy & Security, scroll to Security, select Open Anyway, authenticate, then select Open.
In Arc for Chrome setup, choose Move from Arc and select the new .arcsidebar file from Downloads.

The import can preserve Spaces, Top Apps, saved tabs, folders, titles, order, Archive, locally available history, and cached icons. Arc’s official data export is available as a limited fallback.

Imports are read only after you choose a file and are processed locally.

Install the compact layout helper

Download and unzip the compact layout helper.
In Arc for Chrome setup, select Copy extension ID.
Open Install Arc for Chrome Helper.command once. If macOS blocks it or offers to move it to Trash, dismiss the warning. Open System Settings → Privacy & Security, scroll to Security, select Open Anyway, authenticate, then select Open and paste the ID.
If Accessibility opens, select +, press Command-Shift-G, enter /usr/bin/osascript, select Open, and enable it.
Return to setup and select Recheck helper.

To remove it, run uninstall-macos-helper.sh. Arc for Chrome then uses Chrome’s built-in window API.

Is it safe?

Arc for Chrome is local-first: no account, analytics, advertising, tracking, updater, or publisher-operated server. Browsing data is used only for the sidebar features and is not sent to the developer.

What the extension can read

Open tabs, Chrome history, recently closed tabs, and favicons so it can display Tabs, History, Archive, and search.
Local display bounds so the compact layout stays on the correct monitor.
Only migration or backup files you explicitly choose.

Why macOS shows security prompts

The optional helpers are downloadable local scripts rather than App Store apps, so Gatekeeper may block them. Open the file once, dismiss the warning, then approve it from System Settings → Privacy & Security → Security → Open Anyway. The compact helper requests Accessibility only to move the front Chrome window. It cannot read tabs, history, page contents, passwords, accounts, or network traffic.

How to verify or remove everything

Compare a download with the published SHA-256 checksums.
Remove Accessibility access in System Settings → Privacy & Security → Accessibility.
Run uninstall-macos-helper.sh to remove the compact helper.
Remove the Chrome extension and clear its data to delete all local extension storage.

Help

The sidebar does not open

Open the toolbar extension menu, select Arc for Chrome, and pin it. You can also use Control+S on macOS or Alt+S elsewhere.

History or Archive is empty

History shows Chrome history available in the current Chrome profile. Archive shows recently closed Chrome tabs and windows. Arc history requires a local migration bundle.

Switch to the previous tab

Use Control+Q on macOS or Alt+Q elsewhere.

Remove all local extension data

Remove the extension from Chrome and choose to clear its data. The extension has no publisher account or remote copy to delete.

macOS says the helper cannot be opened

Open the .command file once. If macOS says it cannot verify the file or offers to move it to Trash, dismiss the warning—do not move the file to Trash. Open System Settings → Privacy & Security, scroll to Security, select Open Anyway, authenticate, then select Open. If Open Anyway is missing, try opening the file once more and return to Privacy & Security. Download helpers only from this page and verify the checksum if desired.

Accessibility does not list osascript

Select +, press Command-Shift-G, enter /usr/bin/osascript, select Open, then enable it. Return to Arc for Chrome and select Recheck helper.