Render Profiler

Render Profiler is a development tool to help visualize and debug the render tree and cacheability metadata for a given page,

• Display a page's render tree in a collapsible UI, showing render and query times for each item
• Collects and traces bubbled cache metadata, allowing you to see where any given tag or context originated from
• Optionally annotates slow rendering elements on the page, and discovers elements that were rendered but not printed.

Installation

This module requires no modules outside of Drupal core. Install as you would normally install a contributed Drupal module.

Usage

• Ensure the "Use Render Profiler" permission is set for the appropriate roles on Drupal's permissions page
• Optionally configure annotation settings in "Admin > Configuration > Development > Render Profiler settings"
• Add the query parameter "RENDER_PROFILER_START=1" to any page URL to run the profiler on that page; results will be shown at page bottom
• Alternatively use the query parameter "RENDER_PROFILER_START_SILENT=1" to run the profiler without altering the page output; view the saved results at /render-profiler/1 (you may use any string for the parameter value)

Important notes

• Annotations get cached in render, page, and dynamic_page_cache bins. It may be a good idea to disable these bins in settings.local.php if you have them enabled.
• Be aware that for any rendered thing, there is render time and there is build time. This module faithfully presents a tree branch's render time, but there was probably build time for that branch that would be represent somewhere shallower on the tree.