Clipboard API

Thesystem clipboardis a data buffer belonging to the operating system hosting the browser, which is used for short-term data storage and/or data transfers between documents or applications. It is usually implemented as an anonymous, temporarydata buffer,sometimes called thepaste buffer,that can be accessed from most or all programs within the environment via defined programming interfaces.

The Clipboard API allows users to programmatically read and write text and other kinds of data to and from the system clipboard insecure contexts,provided the user has met the criteria outlined in theSecurity considerations.

Events are fired as the result ofcut,copy,andpasteoperations modifying the clipboard. The events have a default action, for example thecopyaction copies the current selection to the system clipboard by default. The default action can be overriden by the event handler — see each of the events for more information.

ClipboardSecure context

Provides an interface for reading and writing text and data to or from the system clipboard. The specification refers to this as the 'Async Clipboard API'.

ClipboardEvent

Represents events providing information related to modification of the clipboard, that iscut,copy,andpasteevents. The specification refers to this as the 'Clipboard Event API'.

ClipboardItemSecure context

Represents a single item format, used when reading or writing data.

The Clipboard API extends the following APIs, adding the listed features.

Navigator.clipboardRead onlySecure context

Returns aClipboardobject that provides read and write access to the system clipboard.

Element: copyevent

An event fired whenever the user initiates a copy action.

Element: cutevent

An event fired whenever the user initiates a cut action.

Element: pasteevent

An event fired whenever the user initiates a paste action.

The Clipboard API allows users to programmatically read and write text and other kinds of data to and from the system clipboard insecure contexts.

The specification requires that a user has recently interacted with the page in order to read from the clipboard (transient user activationis required). If the read operation is caused by user interaction with a browser or OS "paste element" (such as a context menu), the browser is expected to prompt the user for acknowledgement. For writing to the clipboard the specification expects that the page has been granted thePermissions APIclipboard-writepermission, and the browser may also requiretransient user activation. Browsers may place additional restrictions over use of the methods to access the clipboard.

Browser implementations have diverged from the specification. The differences are captured in theBrowser compatibilitysection and the current state is summarized below:

Chromium browsers:

• Reading requires thePermissions APIclipboard-readpermission be granted. Transient activation is not required.
• Writing requires either theclipboard-readpermission or transient activation. If the permission is granted, it persists, and further transient activation is not required.
• The HTTPPermissions-Policypermissionsclipboard-readandclipboard-writemust be allowed for<iframe>elements that access the clipboard.
• No persistent paste-prompt is displayed when a read operation is caused by a browser or OS "paste element".

Firefox & Safari:

• Reading and writing require transient activation.
• The paste-prompt is suppressed if reading same-origin clipboard content, but not cross-origin content.
• Theclipboard-readandclipboard-writepermissions are not supported (and not planned to be supported) by Firefox or Safari.

FirefoxWeb Extensions:

• Reading text is only available for extensions with the Web ExtensionclipboardReadpermission. With this permission the extension does not require transient activation or a paste prompt.
• Writing text is available in secure context and with transient activation. With the Web ExtensionclipboardWritepermission transient activation is not required.

The system clipboard is accessed through theNavigator.clipboardglobal.

This snippet fetches the text from the clipboard and appends it to the first element found with the classeditor. SincereadText()(andread(),for that matter) returns an empty string if the clipboard isn't text, this code is safe.

navigator.clipboard
.readText()
.then(
(clipText)=>(document.querySelector(".editor").innerText+=clipText),
);

• Image support for Async Clipboard article