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.

tierrainnovation

Render database profiling at the bottom of all WordPress pages. To install, upload <code>wpdb-profiling</code> to the <code>/wp-content/plugins/</code> directory, activate the plugin, and enable / disable features from the wp-admin plugin screen.

WPDB Profiling

This plugin will give you the total number of queries to the db per page, as well as the total time it took to render those queries out to the page.

Block Weight Inspector vs WPDB Profiling