Why does the clipboard work in one tab but not another?

Some sites use restrictive Content Security Policies or sandboxed iframes that block clipboard access. Use a top-level page for the action.

Do I need permissions for clipboard read?

Yes, browsers prompt for read access. Revoke and re-grant via site settings if you previously denied it.

Does Safari support navigator.clipboard?

Yes in modern versions, but only on HTTPS and with a user gesture. Older versions need execCommand fallbacks.

Browser Diagnostics

Clipboard Test

Copy and paste safely

Clipboard

Copy & paste capability test

Not available

Why clipboard access can fail

Browsers require a user gesture (like a click) to read or write the clipboard, and some contexts (iframes, http) are blocked entirely. This test runs permission-safe read/write checks so you can validate before shipping copy/paste features.

If writes fail, ensure the page is served over HTTPS and the action is triggered from a trusted event handler. Some password managers also intercept clipboard operations; try disabling them temporarily.

Troubleshooting steps

Fix clipboard issues →

FAQ

Why does the clipboard work in one tab but not another?: Some sites use restrictive Content Security Policies or sandboxed iframes that block clipboard access. Use a top-level page for the action.
Do I need permissions for clipboard read?: Yes, browsers prompt for read access. Revoke and re-grant via site settings if you previously denied it.
Does Safari support navigator.clipboard?: Yes in modern versions, but only on HTTPS and with a user gesture. Older versions need execCommand fallbacks.