devmarvs

Block Weight Inspector adds a sidebar panel in the block editor that maps blocks in the current post/page to the CSS and JS assets they register. It estimates local asset sizes, highlights top offenders, and exports a JSON report. It can also generate a suggested conditional-loading snippet to help you dequeue assets when a block is not present. 
It also adds a Tools -> Block Weight Inspector screen for auditing existing posts without opening the editor. 
Note: The inspector preserves block comment delimiters when analyzing content so <code>parse_blocks()</code> remains accurate after sanitization.
Key features:
<ul>
<li>Block -> asset mapping using registered block metadata.</li>
<li>Estimated size for local assets.</li>
<li>Top offenders summary and full asset list.</li>
<li>JSON export for sharing or auditing.</li>
<li>Suggested conditional-loading rules (review before use).</li>
</ul>

Block Weight Inspector

See which blocks load which CSS/JS assets on a page and estimate their weight.

Amit Gupta

This plugin is to lookup which hooks are slow in execution in plugins and current theme.
This plugin needs <a href="https://wordpress.org/plugins/debug-bar/" rel="ugc">Debug Bar</a> plugin to be installed and activated. It adds a panel labelled “PMC Benchmark” in it.
This plugin is for use in development environment only and not meant for use in a production environment.
Github: https://github.com/Penske-Media-Corp/pmc-benchmark

PMC Benchmark

A benchmarking plugin to profile slow hooks.

Block Weight Inspector vs PMC Benchmark