You press Command+C, switch to another window, press Command+V, and nothing happens. Or worse, the wrong thing pastes, the item you copied two minutes ago. It feels alarming because copy and paste is the one thing that is supposed to always work. The good news is that on a Mac this is one of the most fixable problems there is, and you almost certainly will not need to restart the whole machine to sort it out.
The reason it breaks is worth understanding, because it tells you which fix to reach for. macOS does not store your copied text in a file. It hands it to a tiny background service called pboard, the pasteboard server, which holds whatever you copied last and serves it back when you paste. When pboard hangs, copying seems to succeed but pasting either fails or returns stale text. Most Mac copy and paste trouble traces back to that one stuck process.
First, rule out the obvious
Before touching anything technical, run two quick checks. They take ten seconds and save you from fixing a problem that was never there.
- Confirm you are using Command, not Control. On a Mac, copy is Command+C and paste is Command+V. If you have recently switched from Windows, Control+C and Control+V do nothing useful here. Switchers hit this far more often than any stuck process.
- Test in a second app. Copy a word in your browser and try pasting it into Notes or the Spotlight search bar. If it pastes there, the problem is the first app, not your Mac. If it fails everywhere, read on.
The one fix that solves most cases: restart pboard
If pasting is dead across every app, restart the pasteboard server. You are not deleting anything. You are telling macOS to throw away the stalled process and start a clean one, which it does instantly.
Using Terminal
- Open Terminal from Applications, then Utilities. Spotlight works too: press Command+Space, type Terminal, and press Return.
- Type killall pboard and press Return.
- Nothing visible happens, and that is exactly right. macOS relaunches pboard on its own.
- Switch to any app and test Command+C and Command+V. It should work again.
The word “kill” sounds dramatic, but here it just means quit. macOS treats pboard as essential and brings it straight back, so there is no risk of leaving your clipboard permanently broken.
Using Activity Monitor instead
If you would rather not use the command line, you can do the same thing with a few clicks. Open Activity Monitor from Applications then Utilities, type pboard into the search box at the top right, select the process, click the stop button (the octagon with an x), and choose Quit. macOS restarts it, and your clipboard is freed up.
If restarting pboard did not fix it
A stuck pasteboard server covers the large majority of cases, but not all. Work through these next, in order.
Quit the app that will not paste
If copy and paste works everywhere except one program, that program has lost the plot, not your Mac. Quit it fully with Command+Q rather than just closing the window, then reopen it. Browsers, Office apps and Electron apps like Slack are the usual suspects. If you only see the trouble inside a spreadsheet, it may be an app-level quirk rather than the clipboard, and our guide to copy and paste not working in Excel walks through those.
Check whether it is the keyboard, not the clipboard
If the shortcuts feel completely dead but the right-click menu still copies and pastes fine, suspect the keyboard. A stuck modifier key, a flat Bluetooth keyboard, or Sticky Keys left switched on can all swallow Command+C. Try the right-click menu (Control-click or a two-finger tap on the trackpad), then Edit then Copy from the menu bar. If the menus work and the keys do not, the issue is input, not the clipboard. This overlaps with the broader copy and paste shortcuts not working fixes, which apply to Mac keys too.
Restart your Mac as the reset of last resort
If none of the above lands, a full restart clears every stuck process at once, pboard included, and resolves the stubborn cases. Use Apple menu then Restart. It is blunt, but it works, and it is faster than chasing a rare cause for half an hour.
Why this keeps happening, and how to make it rarer
The Mac clipboard holds exactly one item and trusts a single background process to manage it. That design is lean and fast, but it has no safety net: if pboard stalls or an app grabs the pasteboard and holds it, you get the dead-paste symptom with nothing to fall back on. macOS keeps no history you can dip into, so a lost copy is simply gone. This is the same single-slot limitation behind the wider question of why copy and paste stops working across devices.
A couple of habits cut down how often it bites. Keep macOS and your apps updated, since clipboard bugs do get patched. Be choosy about clipboard managers and keep the one you use current. And if losing a copy is something you genuinely cannot afford, a proper clipboard manager that keeps real history removes the single point of failure, because your text is saved before a stuck process can swallow it.
For the vast majority of people, though, the whole problem comes down to one tired background service. Quit pboard, let macOS start a fresh one, and copy and paste comes straight back to life.