Is allowing clipboard access safe?

Allow it only for sites you trust. The permission is scoped to the site you approve, and you can revoke it anytime in site settings.

Why does paste fail only in private windows?

Private mode can restrict storage and permissions, and some extensions still run there. Test in a normal window, or disable extensions for private windows.

Can antivirus block clipboard?

Rarely. If security software injects clipboard protection, add the browser to its trusted list or temporarily pause that feature while you test.

Fix Copy and Paste Not Working in Chrome, Edge, or Firefox (Run the Clipboard Test)

Confirm copy and paste with the Clipboard Test

Open the Clipboard Test. Use Copy sample text and then Paste. If either action fails or the permission prompt never appears, keep the tab open and rerun after each fix. Real-world signs include paste buttons that stay grey, password managers that cannot fill fields, or sites that say "clipboard access denied."

Fix 1: Allow clipboard permission for the site

Browsers guard clipboard access behind a prompt.

Click the lock icon in the address bar and set Clipboard (or Clipboard and blocked images in some builds) to Allow for the site.
Chrome/Edge: Settings > Privacy and security > Site settings > Additional permissions > Clipboard. Move the site from Not allowed to Allowed.
Firefox: about:config → set dom.events.asyncClipboard to true (default) and ensure you accept the permission prompt when asked.
Reload and rerun the Clipboard Test.

Fix 2: Use a user gesture

Clipboard access requires a click or keyboard shortcut.

Trigger copy/paste with Ctrl/Cmd+C and Ctrl/Cmd+V or a button click. Background scripts without a gesture will be blocked.
If the site provides a copy button, click it directly instead of using the browser menu while the tab is inactive.

Fix 3: Disable extensions that filter clipboard data

Security and privacy extensions can intercept copy/paste.

Turn off extensions like Clipboard blockers, security sandboxes, heavy password managers, and user-agent spoofers to test.
Open the site in Incognito/InPrivate (extensions off) to confirm. If the clipboard works there, re-enable extensions one by one or add the site to their allowlists.

Fix 4: Check OS clipboard managers and enterprise controls

Close third-party clipboard managers that lock the clipboard history.
On managed Windows machines, IT can disable clipboard sync between apps. Ask if Group Policy > User Configuration > Administrative Templates > Windows Components > Remote Desktop Services > Device and Resource Redirection is restricting clipboard redirection.
If you are in a remote desktop session, enable clipboard sharing in the RDP or virtualization client.

Fix 5: Clear corrupted site data

Stale permissions or content-security settings can block clipboard calls.

Open Settings > Privacy and security > Cookies and other site data > See all site data and permissions.
Remove the entry for the site that cannot copy/paste.
Reload, grant clipboard permission again, and rerun the Clipboard Test.

Fix 6: Avoid paste-blocking input restrictions

Some sites intentionally block paste on password or OTP fields.

If you see a blocked cursor, paste into another field first, then drag and drop, or use the site's official paste button.
On enterprise apps, check for a built-in "Allow paste" toggle; if missing, contact the admin rather than using hacks that violate policy.

Fix 7: Update the browser

Clipboard API bugs are fixed quickly in new releases.

Update Chrome/Edge/Firefox via Help > About and relaunch.
Retest with the Clipboard Test. If it still fails only in one profile, create a fresh profile to rule out profile corruption.

Verify the fix

Run the Clipboard Test again. Both Copy and Paste should succeed without errors. Then try the real app—paste a verification code or copy a task link—to confirm. If managed policies still block clipboard access, share the failing result with IT and request a site-specific allowlist.