debugger - JavaScript | MDN (original) (raw)

Baseline

Widely available

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

Syntax

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 debuggerstatement. It is like a breakpoint in the script source.

A browser with developer tools open to the debugger panel showing how execution is paused at the debugger statement to allow close inspection of variables, scopes, events, etc.

Specifications

Specification
ECMAScript® 2026 Language Specification # sec-debugger-statement

Browser compatibility

See also