Short answer: Chrome has a built-in guard (Warn Before Quitting). Safari has none. For Arc we could not confirm a built-in guard on a current build, so treat Arc like Safari and protect it from outside.
| Chrome | Safari | Arc | |
|---|---|---|---|
| Built-in quit guard | Yes, off by default | No | Not confirmed |
| Where | Chrome menu › Warn Before Quitting | None | Check the Arc menu on your copy |
| Reopens tabs after a quit | Settings › On startup › Continue where you left off | Settings › General › Safari opens with | Keeps your spaces and pinned tabs |
| App Shortcuts remap | Quit Google Chrome | Quit Safari | Quit Arc |
Open the Chrome menu in the menu bar and tick Warn Before Quitting. A tap of Cmd Q then shows "Hold ⌘Q to Quit" and nothing closes. Other Chromium browsers such as Edge and Brave have the same item. It is the best single change if Chrome is where you lose work.
Safari has no quit warning and never has. The nearest help is reopening: set Safari › Settings › General › Safari opens with to "All windows from last session". The quit still happens and text typed into forms is lost.
Arc is built on Chromium but uses its own menus and settings. We could not confirm that current Arc builds include Chrome's Warn Before Quitting item. If your copy shows that item, tick it. If not, use one of the fixes below. Arc's maker, The Browser Company, has said its new work goes into its newer browser, Dia, so a new setting in Arc is unlikely.
Remap Quit per app. System Settings › Keyboard › Keyboard Shortcuts › App Shortcuts, click +, pick the browser, type the menu title exactly (for example Quit Arc) and assign a shortcut you will never press by accident. Cmd Q then does nothing in that browser. Steps and catches are in how to disable Cmd Q on a Mac.
Guard the shortcut. A hold-to-quit tool covers every app with one setting. Still Dock guards Cmd Q in the apps you choose: the direct download makes a quit need a hold, and the Mac App Store version needs a second press. Choose Safari and Arc and leave the rest alone.
Yes. Firefox › Settings › General, tick Confirm before quitting with ⌘Q. More in stopping Cmd Q quitting Chrome, Safari and Firefox.
Usually. Reopen the browser and press Shift Command T, or use the History menu. Typed text in forms is usually gone.
That is a separate key with separate fixes: see stop Cmd W closing all tabs.