SRD75

Once the Memory Usage Monitor plugin is activated, activating or deactivating any other plugin will display the memory used by that plugin. e.g:
Memory usage for WP Memory: 0.02 MB
For accurate memory usage breakdown for each plugin, you must activate or deactivate them individually; you will not see memory usage when bulk activating plugins.

Memory Usage Monitor

Displays memory/RAM usage for each plugin as they are activated and deactivated.

berkux

WP-Memory-Usage is a lightweight but powerful WordPress plugin that monitors and displays memory usage directly in your WordPress admin area. 
This tool is essential for site administrators and developers who need to keep an eye on the memory consumption of their WordPress installation, helping to identify potential issues and optimize performance.
What the plugin shows:
In the admin footer (every admin page): 
* Current memory usage vs. WordPress limit (with percentage) 
* Current memory usage vs. PHP limit (with percentage) 
* Server IP address and server name 
* PHP version
In the Dashboard widget (“Memory Overview”): 
* PHP version, architecture (32/64 bit), max execution time 
* WordPress memory limit (WP_MEMORY_LIMIT), WordPress admin limit (WP_MAX_MEMORY_LIMIT), PHP memory limit 
* Current peak memory usage with a visual progress bar (colour-coded: green / orange / red) 
* Link to the Threshold Alerts settings page
Memory Alerts Tabs (since 2.0.0): 
Log events, set thresholds (Warning / Danger / Critical), monitor memory usage…
<h3>Why Use WP-Memory-Usage?</h3>
Excessive memory usage leads to slower sites, HTTP 500 errors, and failed background jobs (cron, imports, backups). WP-Memory-Usage gives you the information you need to act before users are affected — without overwhelming you with notifications.
<h3>Features</h3>
<ul>
<li>Admin menu: See at settings “Memory Alerts”</li>
<li>Real-time memory display in dashboard and every admin page footer</li>
<li>Colour-coded progress bar (green / orange / red) for instant status recognition</li>
<li>Set Thresholds: Set values for three threshold levels (Warning, Danger, Critical) and switch on/off logging</li>
<li>Set how to measure: Use peak memory?</li>
<li>Set Logging: Log Ajax, Rest, Admin, Cron, favicon, OK</li>
<li>Set how to alert: Mailadress, intervals for rotating and deleting logfiles</li>
<li>History tab: show latest logged requests</li>
<li>Digest tab: browse and review past aggregated requests</li>
<li>Actions tab: practical guidance on what to do when you receive an alert</li>
<li>Memory Thresholds tab: current settings and assessment & recommendations</li>
<li>Check Installation tab: all ok for using this plugin?</li>
<li>Clean uninstall: removes all options, cron jobs, and log files on deletion</li>
<li>New Logo for the Plugin</li>
</ul>
<h3>PluginCheck-Plugin Status</h3>
Plugin is compatible with PluginCheck-Plugin. Note regarding “trademarked_term”: “WP-Memory-Usage” and “wp-memory-usage” are today considered restricted terms. This plugin entered the WordPress repository in 2009, when those terms were permitted.
<h3>Credits</h3>
Copyright 2009–2013 by Alex Rabe, 2022– Bernhard Kux

WP-Memory-Usage

Show up the PHP version, memory limit and current memory usage in the dashboard and admin footer. Optional monitor threshold and alert via email.

Memory Usage Monitor vs WP-Memory-Usage