Chrome browser debug logs
Chrome browser debug logs help you to troubleshoot problems with Chrome, such as hanging tabs or error messages. By default, browser debug logs aren’t generated, so you’ll need to enable logging before you can use them to diagnose a problem.
Debug logs are stored in the user data directory as chrome_debug.log. The file is overwritten every time Chrome restarts. So, if you have an issue with the browser, check the log before you restart Chrome. You can stop the file from being overwritten by moving it to the desktop.
Read the logs
Tools like Sawbuck on Microsoft® Windows® or Console on Apple® Mac® (located at Applications > Utilities > Console) can help you read the logs and find the source of a problem. These tools present the logs in a graphical user interface that you can easily view, filter, and search.
You can also open the file in a text editor and use the information below to identify problems.
What to look for
The first thing to look for in the chrome_debug.log file is the ERROR keyword. However, depending on the issue, this may not be the root cause. For example, if a user reports excessively long start times, you may see repeated lines at the beginning of the debug log or a high number of process IDs (PIDs) or thread IDs (TIDs).
Each line of the log file begins in a time-stamp format with the following elements:
PROCESS_ID: The identifier of the process that's currently running.
THREAD_ID: A process within a PID.
MMDD: The current month and day. In the example above it's Aug 9.
TIME: The current time in a 24-hour format of HH:MM:SS, which will help you narrow your search to the time an issue happened.
LOGGING_LEVEL: The current level of logging. This is usually VERBOSE1 as set by the command line. You may also see occurrences of ERROR.
SOURCE_CODE_FILE_NAME(LINE_NUMBER): The name of the source-code file that triggered the event to be logged.