Profiler

Magento profiler can help you with the store performance tuning before the store release or during the exploitation.
The old UI for enabling/disabling the profiler is not available in Magento 2 and the profiler is disabled by default.
To enable one of the profiler formats mentioned above, you can edit .htaccess (a configuration file for Apache Web Server software):

    Choose one of the next expressions:

To enable the profiler we can add it from index.php or apache/nginx conf file.

Enable/Disable Profiler from Command Line:
# Enable the profiler.
php bin/magento dev:profiler:enable
# Disable the profiler.
php bin/magento dev:profiler:disable

Enable Profiler from index.php: