debugger

The debugger invokes any available debugging functionality, such as setting a breakpoint. If no debugging functionality is available, this statement has no effect.

Syntax

debugger;

Examples

Using the debugger statement

The following example shows code where a debugger statement has been inserted, to invoke a debugger (if one exists) when the function is called.

function potentiallyBuggyCode() {
    debugger;
    // do potentially buggy stuff to examine, step through, etc.
}

When the debugger is invoked, execution is paused at the debugger statement. It is like a breakpoint in the script source.

Paused at a debugger statement.

Specifications

Browser compatibility

Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet
debugger
5
12
1
4
10
5
1
18
4
10.1
4.2
1.0

See also

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https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/debugger