Dragon Speed Doctor – Find What Slows Your Site Down

Description

Every slow WordPress site raises the same question: which plugin is doing this? Dragon Speed Doctor answers it with measurements, not guesswork.

Install the measurement loader, press Run diagnosis, and the doctor times your site over a few minutes of internal test requests, with each plugin briefly left out of those test requests only, then tells you what each plugin actually costs:

• Per-plugin timing, front-end and wp-admin: “Adds about 180–260ms to page loads.” Real measured ranges, never invented precision. When results are too noisy to trust, it says so instead of making a number up.
• Asset audit: every script and stylesheet on your pages, attributed to the plugin that ships it, with sizes and render-blocking flags. Sometimes a plugin’s PHP is fast but it sends 900KB of JavaScript to every visitor, and the doctor catches that too.
• Database signals: autoloaded-option weight (a common hidden slowdown) with probable owners.
• Plain-English verdicts with Low / Medium / High impact badges, sorted worst first, and an Inconclusive badge when the timings cannot support an answer.
• Before/after comparison: run a scan before updating plugins and another after, and see what changed. A rolling history of recent scans is kept automatically.
• Dependency awareness: plugins that declare they need another plugin (a WooCommerce payment gateway, say) are measured together and labelled honestly; a plugin the site cannot run without is reported as “could not be measured”, never as harmless.
• WP-CLI: wp speed-doctor scan.

Visitors are never affected: plugin loading is only altered for the doctor’s own internal, cryptographically signed test requests. Your live traffic always sees the site exactly as configured.

Features

• Per-Plugin Timing – What each plugin costs on the front end and in wp-admin, as honest measured ranges
• Asset Audit – Every script and stylesheet on your pages, attributed to the plugin that ships it, with render-blocking flags
• Database Signals – Autoloaded-option weight and probable owners, a common hidden slowdown
• Plain-English Verdicts – Low, Medium, High and Inconclusive badges, sorted worst first, no jargon
• Before & After – Scan before updating plugins and again after, and see exactly what changed
• Dependency Awareness – Plugins that cannot be separated are measured together and labelled honestly
• Honest Confidence – Rates a plugin Low only when the top of every measured range stays at or below 100ms, never calls a difference smaller than the server’s own noise a cost, and says “inconclusive” when the server is too noisy, or when a small cost on one page sits next to a page that was not measured, instead of inventing a number
• WP-CLI – wp speed-doctor scan for scripted or scheduled diagnosis
• No External Services – Everything runs on your own server; nothing is sent anywhere

Everything above is free, fully functional and unlimited.

How it measures

The method is built for noisy shared hosting: repeated interleaved timings, medians with confidence bands, warmup passes discarded, early stopping when a result is already clear, retries for passing server errors, and honest “inconclusive” verdicts when server noise wins. Script and stylesheet weight counts towards a plugin’s badge only for what it loads on front-end pages; wp-admin-only assets are listed on the Assets tab but never described as shipped to visitors. A pre-scan check verifies your site can be measured (loopback requests allowed, no page cache serving the test requests, no background jobs adding noise) before anything runs.

The measurement loader

Timing a plugin’s absence requires briefly loading the site without it, for signed internal requests only. A small helper file in mu-plugins does this. It is installed only when you click Install loader on the Doctor screen (or run wp speed-doctor scan), shown there with its status, does nothing for any normal request, and is removed automatically when you deactivate the plugin. Once installed, it is brought up to date by itself after each plugin update, and a loader you removed stays removed.

Dragon Speed Doctor Pro

Dragon Speed Doctor Pro is an optional annual add-on that keeps the doctor running:

• Scheduled scans, weekly or daily, plus a follow-up scan after every plugin, theme or WordPress update.
• A 12-month performance history with the biggest movers between any two scans.
• Slowdown alerts by email, Slack or signed webhook, sent only after a second scan confirms them, naming what changed.
• A per-plugin breakdown of the database queries and outgoing HTTP calls behind each verdict.

Nothing in this plugin is locked or limited without it.

External services

None. The doctor measures your site by requesting your own pages from your own server. Nothing is sent to Dragon Core or any third party. No telemetry, no accounts, no cloud.

Credits

The WordPress.org listing icon is drawn with glyphs from Lucide (https://lucide.dev), ISC License. Copyright (c) for portions of Lucide are held by Cole Bemis 2013-2022 as part of Feather (https://feathericons.com, MIT License). All other copyright (c) for Lucide are held by Lucide Contributors 2022. The plugin itself does not include these icons.

Technical details