This API method allows script authors simple access to logging informational messages in the Error Console.
If you aren't seeing your messages, make sure you navigate to about:config, and change the values of
The output produces the namespace, the name of the script, and the string.
#namespace/myScript: Hello World!
GM_log( message )
- Value: Function
- Returns: undefined
- Compatibility: Greasemonkey 0.3b+
- All properties are optional except message.
- Value: String, Integer or Boolean
message = "ARGHHH!";
GM_log("Warning, " + someInputField.value + "!");
GM_log and Firebug
Since Firebug 1.0,
extensions.firebug.showChromeMessages must be set to
true for GM_log messages to show up in the Firebug console.
It is also recommended to enable
extensions.firebug.showChromeErrors, as doing so will reveal syntax errors and script breaks.
This can be done from
about:config, or from the Firebug GUI. Go to the "Console" tab, then click the arrow next to the tab's name, and ensure that "Show Chrome Errors" and "Show Chrome Messages" are checked.
However, one should note that since
GM_log converts any passed parameter to a string, and works from the Chrome, it would be more advisable to simply use
console.log, which will allow you to take advantage of Firebug's DOM Inspector on the logged objects.