Document: execCommand() method
Deprecated: This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. Avoid using it, and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.
The execCommand
method implements multiple different commands. Some of them provide access to the clipboard, while others are for editing form inputs, contenteditable
elements or entire documents (when switched to design mode).
To access the clipboard, the newer Clipboard API is recommended over execCommand()
. However, there is no replacement for the editing commands: unlike direct DOM manipulation, modifications performed by execCommand()
preserve the undo buffer (edit history).
Most commands affect the document's selection. For example, some commands (bold, italics, etc.) format the currently selected text, while others delete the selection, insert new elements (replacing the selection) or affect an entire line (indenting). Only the currently active editable element can be modified, but some commands (e.g. copy
) can work without an editable element.
Note: Modifications performed by execCommand()
may or may not trigger beforeinput
and input
events, depending on the browser and configuration. If triggered, the handlers for the events will run before execCommand()
returns. Authors need to be careful about such recursive calls, especially if they call execCommand()
in response to these events. From Firefox 82, nested execCommand()
calls will always fail, see bug 1634262.
Syntax
execCommand(aCommandName, aShowDefaultUI, aValueArgument)
Parameters
aCommandName
-
A string specifying the name of the command to execute. The following commands are specified:
backColor
-
Changes the document background color. In
styleWithCss
mode, it affects the background color of the containing block instead. This requires a<color>
value string to be passed in as a value argument. bold
-
Toggles bold on/off for the selection or at the insertion point.
contentReadOnly
-
Makes the content document either read-only or editable. This requires a boolean true/false as the value argument.
copy
-
Copies the current selection to the clipboard. Conditions of having this behavior enabled vary from one browser to another, and have evolved over time. Check the compatibility table to determine if you can use it in your case.
createLink
-
Creates an hyperlink from the selection, but only if there is a selection. Requires a URI string as a value argument for the hyperlink's
href
. The URI must contain at least a single character, which may be whitespace. cut
-
Removes the current selection and copies it to the clipboard. When this behavior is enabled varies between browsers, and its conditions have evolved over time. Check the compatibility table for usage details.
decreaseFontSize
-
Adds a
<small>
tag around the selection or at the insertion point. defaultParagraphSeparator
-
Changes the paragraph separator used when new paragraphs are created in editable text regions.
delete
-
Deletes the current selection.
enableAbsolutePositionEditor
-
Enables or disables the grabber that allows absolutely-positioned elements to be moved around. The grabber is disabled by default since Firefox 64 (Firefox bug 1490641).
enableInlineTableEditing
-
Enables or disables the table row/column insertion and deletion controls. The controls are disabled by default since Firefox 64 (Firefox bug 1490641).
enableObjectResizing
-
Enables or disables the resize handles on images, tables, and absolutely-positioned elements and other resizable objects. The handles are disabled by default since Firefox 64 (Firefox bug 1490641).
fontName
-
Changes the font name for the selection or at the insertion point. This requires a font name string (like
"Arial"
) as a value argument. fontSize
-
Changes the font size for the selection or at the insertion point. This requires an integer from
1
-7
as a value argument. foreColor
-
Changes a font color for the selection or at the insertion point. This requires a hexadecimal color value string as a value argument.
formatBlock
-
Adds an HTML block-level element around the line containing the current selection, replacing the block element containing the line if one exists (in Firefox,
<blockquote>
is the exception — it will wrap any containing block element). Requires a tag-name string as a value argument. Virtually all block-level elements can be used. (Legacy Edge only supports heading tagsH1
–H6
,ADDRESS
, andPRE
, which must be wrapped in angle brackets, such as"<H1>"
.) forwardDelete
-
Deletes the character ahead of the cursor's position, identical to hitting the Delete key on a Windows keyboard.
heading
-
Adds a heading element around a selection or insertion point line. Requires the tag-name string as a value argument (i.e.,
"H1"
,"H6"
). (Not supported by Safari.) highlightColor
-
Changes the background color for the selection or at the insertion point. Requires a color value string as a value argument.
useCSS
must betrue
for this to function. increaseFontSize
-
Adds a
<big>
tag around the selection or at the insertion point. indent
-
Indents the line containing the selection or insertion point. In Firefox, if the selection spans multiple lines at different levels of indentation, only the least indented lines in the selection will be indented.
insertBrOnReturn
-
Controls whether the Enter key inserts a
<br>
element, or splits the current block element into two. insertHorizontalRule
-
Inserts a
<hr>
element at the insertion point, or replaces the selection with it. insertHTML
-
Inserts an HTML string at the insertion point (deletes selection). Requires a valid HTML string as a value argument.
insertImage
-
Inserts an image at the insertion point (deletes selection). Requires a URL string for the image's
src
as a value argument. The requirements for this string are the same ascreateLink
. insertOrderedList
-
Creates a numbered ordered list for the selection or at the insertion point.
insertUnorderedList
-
Creates a bulleted unordered list for the selection or at the insertion point.
insertParagraph
-
Inserts a paragraph around the selection or the current line.
insertText
-
Inserts the given plain text at the insertion point (deletes selection).
italic
-
Toggles italics on/off for the selection or at the insertion point.
justifyCenter
-
Centers the selection or insertion point.
justifyFull
-
Justifies the selection or insertion point.
justifyLeft
-
Justifies the selection or insertion point to the left.
justifyRight
-
Right-justifies the selection or the insertion point.
outdent
-
Outdents the line containing the selection or insertion point.
paste
-
Pastes the clipboard contents at the insertion point (replaces current selection). Disabled for web content.
redo
-
Redoes the previous undo command.
removeFormat
-
Removes all formatting from the current selection.
selectAll
-
Selects all of the content of the editable region.
strikeThrough
-
Toggles strikethrough on/off for the selection or at the insertion point.
subscript
-
Toggles subscript on/off for the selection or at the insertion point.
superscript
-
Toggles superscript on/off for the selection or at the insertion point.
underline
-
Toggles underline on/off for the selection or at the insertion point.
undo
-
Undoes the last executed command.
unlink
-
Removes the anchor element from a selected hyperlink.
useCSS
Deprecated-
Toggles the use of HTML tags or CSS for the generated markup. Requires a boolean true/false as a value argument.
Note: This argument is logically backwards (i.e., use
false
to use CSS,true
to use HTML). This has been deprecated in favor ofstyleWithCSS
. styleWithCSS
-
Replaces the
useCSS
command.true
modifies/generatesstyle
attributes in markup, false generates presentational elements. AutoUrlDetect
-
Changes the browser auto-link behavior.
aShowDefaultUI
-
A boolean value indicating whether the default user interface should be shown. This is not implemented in Mozilla.
aValueArgument
-
For commands which require an input argument, is a string providing that information. For example,
insertImage
requires the URL of the image to insert. Specifynull
if no argument is needed.
Return value
A boolean value that is false
if the command is unsupported or disabled.
Note: document.execCommand()
only returns
true
if it is invoked as part of a user interaction. You can't use it to
verify browser support before calling a command.
Examples
An example of how to use execCommand with contentEditable elements on CodePen.
Using insertText
This example shows two very basic HTML editors, one using a <textarea>
element and one using a <pre>
element with the contenteditable
attribute set.
Clicking the "Bold" or "Italic" buttons inserts the appropriate tags in the element, using insertText
to preserve the edit history, so the user can undo the action.
HTML
<h2>textarea</h2>
<div class="actions" data-for="textarea">
<button data-el="b">Bold</button>
<button data-el="i">Italic</button>
</div>
<textarea class="editarea">Some text.</textarea>
<h2>contenteditable</h2>
<div class="actions" data-for="pre">
<button data-el="b">Bold</button>
<button data-el="i">Italic</button>
</div>
<pre contenteditable="true" class="editarea">Some text.</pre>
JavaScript
// Prepare action buttons
const buttonContainers = document.querySelectorAll(".actions");
for (const buttonContainer of buttonContainers) {
const buttons = buttonContainer.querySelectorAll("button");
const pasteTarget = buttonContainer.getAttribute("data-for");
for (const button of buttons) {
const elementName = button.getAttribute("data-el");
button.addEventListener("click", () =>
insertText(`<${elementName}></${elementName}>`, pasteTarget),
);
}
}
// Inserts text at cursor, or replaces selected text
function insertText(newText, selector) {
const textarea = document.querySelector(selector);
textarea.focus();
let pasted = true;
try {
if (!document.execCommand("insertText", false, newText)) {
pasted = false;
}
} catch (e) {
console.error("error caught:", e);
pasted = false;
}
if (!pasted) {
console.error("paste unsuccessful, execCommand not supported");
}
}
Result
Specifications
Specification |
---|
Trusted Types # dom-document-execcommand |
Browser compatibility
BCD tables only load in the browser