MDN’s new design is in Beta! A sneak peek:

console.warn Redirect 1

« DOM Reference


Outputs a warning message to the Web Console.

Note: In Firefox, warnings have a small exclamation point icon next to them in the Web Console log.


console.warn(obj1 [, obj2, ..., objN);
console.warn(msg [, subst1, ..., substN);


obj1 ... objN
A list of JavaScript objects to output. The string representations of each of these objects are appended together in the order listed and output.
A JavaScript string containing zero or more substitution strings.
subst1 ... substN
JavaScript objects with which to replace substitution strings within msg. This gives you additional control over the format of the output.

See Outputting text to the console in the documentation of console for details.


Not part of any specification.

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
Basic support (Yes) 4.0 (2.0) 8 (Yes) (Yes)
Substitution strings ? 9.0 (9.0) ? ? ?
Feature Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support ? 4.0 (2.0) ? ? ?
Substitution strings ? 9.0 (9.0) ? ? ?

See also

Document Tags and Contributors

 Last updated by: Sheppy,