Tools
Free WordPress speed and architecture tools
Each tool answers one question and runs in your browser: nothing you paste is sent anywhere. Each one links to the article that explains the reasoning behind it.
Calculator
Core Web Vitals budget calculator
Largest Contentful Paint is the sum of four phases and Interaction to Next Paint of three. Enter what you measured for each phase and see where the budget goes.
Open the toolFrom the article How to reduce WordPress TTFB: a diagnostic guide
Analyser
WordPress loads every autoloaded option early in each request. Paste the list from WP-CLI and see the total, the largest rows and the prefixes they share, before you decide what to change.
Open the toolFrom the article WordPress autoloaded options: measure and review wp_options
Checker
WooCommerce cache headers checker
A cached checkout can show one shopper another's cart, and an uncacheable product page makes every visit wait for PHP. Paste a page's response headers and see which you have.
Open the toolFrom the article How to speed up WooCommerce: a Core Web Vitals guide
Decision aid
Should this WordPress site go headless?
Headless WordPress with Next.js suits some sites and is a costly detour for others. Answer eight questions and see which way yours leans, and why.
Open the toolFrom the article Headless WordPress with Next.js: when it fits
Get help reading your results
Send me what a tool showed you and what you are trying to fix, and I will say where I would look next.