As PHP version 5.5 is no longer supported by the community, we strongly recommend new apps use the PHP 7 runtime.

Downloading Logs

App Engine maintains a log of messages that your application emits using the syslog() function from the PHP standard library, as well as other messages printed to the standard error stream. App Engine also records each request in the log. Each log severity level has a fixed buffer size that controls the amount of log information you can access. Normally, you use logging features more at lower log levels; thus, the time window is smaller for log events at these levels.

To browse your app's logs of the last 90 days, you can also use the Logs page in the Cloud Console.

Requesting the logs

For performing more detailed analysis of your application's logs, use the AppCfg tooling delivered with the standalone App Engine SDK to download the log data.

To download logs to a file named mylogs.txt, use the following command: request_logs [DIRECTORY_PATH] mylogs.txt

To view all of the options for this command, run: help request_logs

By default, the command downloads log messages from the current calendar day, which starts at midnight Pacific Time. The default log severity level is INFO, which also includes logs for all higher levels but omits DEBUG level messages. The command overwrites the local log file. You can adjust the number of days, the minimum log level, and whether to overwrite or append to the local log file using command-line options.

You can limit the log messages that are downloaded to just those emitted during request on a given domain name using the --vhost=... option. You can use this to download the logs for your live app using a Google Workspace domain or, excluding log messages emitted by versions you are testing on URLs such as Or you can use it to download just the log messages for a given test domain.