

You already know something is wrong. This plugin tells you what, why, what the root cause is — and exactly how to fix it.
🔴 Try the live demo — no install required
Most WordPress diagnostic tools show you a list of problems. WPHI Diagnostic Suite goes further: it reads your PHP error log, groups every error by severity and frequency, traces each one back to the cause, and checks whether a recent update triggered it. It then gives you a structured “error map” for each error — plain-English explanation, probable cause extracted from the actual function or class that failed, impact level, numbered fix steps, and WP-CLI commands specific to the error type.
It also includes a live error log with its own PHP error handler. Clear it, reproduce the problem, and see exactly which new errors appeared — without wading through weeks of historical noise. This makes it a practical debugging workflow, not just a report.
It does all of this without touching a single row of your data. Every query is SELECT-only. No cleanups, no automation, no risk.
✅ Site owners who see “something is wrong” on their dashboard and don’t know where to start.
✅ Developers who need to diagnose a client site quickly without installing Query Monitor on production.
✅ Agencies managing multiple WordPress sites who need a fast, reliable read on site health before and after maintenance.
✅ Anyone who has ever looked at a PHP error log and not known what to do next.
Most diagnostic plugins show you numbers. This one tells you what the numbers mean for your site, right now — and which plugin, theme, or other issue is responsible.
Error maps, not error lists. When the Error Log Viewer finds a PHP fatal error, it doesn’t just show you the message and file. It opens a structured “error map” with five sections: what this error class means in plain English, the probable cause based on the actual function or class name extracted from the message, the impact on visitors, numbered fix steps specific to this error type, copyable WP-CLI commands, and a prevention tip. A “Call to undefined function wc_get_cart()” gets different advice than a “Cannot redeclare foo()” — because they’re different problems.
A live error log you can clear and retest. Beyond your main PHP error log, the plugin registers its own PHP error handler that captures errors into a separate log you control. Clear it, reproduce the issue, and see exactly which new errors appear — without wading through weeks of accumulated historical noise. This turns error diagnosis into an actual workflow rather than a guessing game.
Change correlation — which update caused it. The What Changed? module tracks every plugin and theme update, activation, and WordPress core update as a timestamped event. When a PHP error appears, it calculates a 0–99 correlation score between the error and the most likely change that caused it — using file-path matching (the error originates inside the updated plugin’s folder) as the primary signal, scoring 80–99 when it’s near-certain. You can see at a glance whether last night’s WooCommerce update is responsible for today’s fatal errors.
Plugin attribution everywhere. It’s not enough to know you have custom database tables. You need to know which plugin owns each one, how many rows each table has, and what would happen if you deactivated that plugin. The Blast Radius module traces every custom table, every scheduled cron job, and every REST API namespace back to the plugin that created it — using callback Reflection, file scanning, and a curated fingerprint database covering 30+ popular plugins.
Recommended diagnostic paths based on your live data. The dashboard reads your current error log, autoload size, overdue cron count, and pending update count, then surfaces the two or three diagnostic paths most likely to lead you to the root cause of your current problem — in the right order. No generic checklists. Paths are ordered by how strongly your live data points to each scenario.
WPHI Diagnostic Suite Lite includes ten read-only diagnostic modules, free forever. Pro adds ten more for twenty in total — see below.
🏥 Health Score Dashboard
An animated 0–100 gauge computed from all module findings. Issues are listed with severity labels and direct links to the relevant module. Opens instantly — no page scan required.
🔍 Error Log Viewer
Parses your PHP error log and groups identical errors by severity and frequency. Each group shows severity, occurrence count, first and last seen timestamps, file path, line number, and a full error map with fix steps and WP-CLI commands. A “What Changed?” button on each card checks whether a recent update correlates with the error’s appearance. Error log search filters live without a page reload and composes correctly with pagination.
Also includes a live error log powered by the plugin’s own PHP error handler — separate from debug.log. Clear it at any time, reproduce the issue, and see exactly which new errors are generated. This makes it a practical debugging workflow: clear, reproduce, read, fix, repeat.
📡 What Changed? — Timeline Correlation
“Something broke after an update” is the most common WordPress problem — and the hardest to diagnose without this. Tracks plugin updates, activations/deactivations, WordPress core updates, and theme changes as timestamped events. Displays them on an interactive SVG timeline alongside PHP error spikes. Each error-to-change pairing gets a 0–99 confidence score: file-path matching (the error originates inside the updated plugin’s folder) scores 80–99 — near-certain attribution. Clicking any correlation finding shows the confidence score, the reasoning, and the specific files involved.
🗄️ DB Health Inspector
Shows every autoloaded option ranked by size with colour-coded severity. Flags orphaned postmeta rows left by removed plugins, and lists every table exceeding 50 MB. Identifies the exact options driving your autoload overhead.
⚡ Autoload Governor
Full per-plugin autoload attribution — know which plugin owns each option. Includes Deep Autoload Diagnostics with five detection passes: orphaned options from removed plugins (80+ plugin fingerprint database), autoloaded transients, duplicate cache clusters, migration remnants from backup tools, and stale WooCommerce sessions. Each finding shows the size in KB and includes a ready-to-run WP-CLI command.
🎯 Blast Radius Analyzer
Every custom database table attributed to its owning plugin — with name, version, and approximate row count. Every non-core cron job attributed via callback Reflection and hook-name fingerprinting. Know exactly which plugins have the deepest footprint on your site and what removing them would affect.
🖼️ Asset Inspector
Every JavaScript and CSS file WordPress enqueues on the front end, with individual file sizes and running totals. If a plugin loads a 400 KB script on pages where it’s not needed, this is where you find it.
🕐 Cron Inspector
Every WP-Cron and Action Scheduler job with its next run time and recurrence interval. Overdue jobs are highlighted — they run on the next page request and spike load for that visitor.
💣 Time Bomb Detector
Checks your SSL certificate expiry and warns you 30 days in advance. An expired SSL certificate is a site outage your visitors experience before you do.
🖥️ Server & PHP Environment
PHP memory limit, max execution time, upload limits, OPcache status, and server software details. The configuration ceiling that caps everything else your site can do.
Beyond the ten modules, Lite includes a built-in Export Report feature: download a self-contained HTML report covering health score, database metrics, error log summary, and system snapshot — useful for sharing findings with a developer or keeping as a pre-maintenance baseline. (Pro expands the report to cover every module in full detail.)
The dashboard evaluates seven common WordPress problem scenarios against your live site data and surfaces the ones most relevant right now:
Each path shows specific errors from your log that triggered the recommendation, so you know exactly what you’re chasing before you open the first module.
Every query this plugin runs is SELECT, SHOW, or SHOW INDEX. It never writes, updates, or deletes anything. There is no cleanup feature, no auto-fix button, no risk. It was designed from the ground up to be safe on live production sites — because that’s where you need a diagnostic tool most.
All ten Lite modules listed above are free forever. No trial period, no nag screens, no email signup, no telemetry, no usage limits.
Install Lite today — ten modules, no account, no expiration — and you already have enough to diagnose most “why did my site break?” emergencies. When you’re ready to go from diagnosing problems to preventing them, Pro runs alongside Lite and adds ten more modules, twenty in total:
You don’t need any of this to get started. Install the free version, find your problem, and upgrade to Pro at any time.