Diagnostic Tools

Tools for evaluating performance issues.

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This page includes information on diagnostics and tools for evaluating performance issues.


Google's Lighthouse provides automated audits for performance, accessibility, progressive web apps, and SEO. Lighthouse audit reports can have a big impact on your frontend performance.

You can configure the audit reports to produce consistent measurements of how your site is experienced by users. The audit reports also highlight areas on your site that can be improved to provide a better user experience.

New Relic

New Relic® Performance Monitoring offers a wide array of metrics that provide a nearly real-time look into web application performance.

Monitor Performance with New Relic

If your site doesn't seem to be able to send uncached content fast enough, enable monitoring services for free with New Relic to help identify bottlenecks.

Helper Tools

There are toolbars for both Drupal and WordPress that provide stats like the number of queries, amount of memory, and response time. These can be helpful for real time debugging.

The Debug Bar plugin can be useful identifying advanced cache behaviors. This plugin requires that you enable debugging via wp-config.php:

 * For developers: WordPress debugging mode.
 * Sets WP_DEBUG to true on if on a non-production environment.
    if ( in_array( $_ENV['PANTHEON_ENVIRONMENT'], array( 'test', 'live' ) ) && ! defined( 'WP_DEBUG', false ) ) {
      define('WP_DEBUG', false);
      define( 'WP_DEBUG', true );
  1. Navigate to a development environment's site URL that has the plugin installed and enabled, with the above configuration in place.

  2. From the WordPress dashboard, click Debug towards the top right.

  3. Review the request and object cache data for potential red flags.

Debug Bar WordPress

The webprofiler module is provided by Devel and generates a helpful toolbar at the bottom which can dig into performance and caching behaviors.

Devel Drupal

For debugging deep and complex server-side performance problems you might need to run your site locally with profiler like Blackfire.