Loupely› Loupely vs. Competitors› Query Monitor
Query Monitor is the leading developer debugging panel for WordPress, trusted by developers who can read raw database queries and PHP error stacks. If you manage your own site and just need to know why your checkout stopped working, or why your form went quiet after a plugin update, Loupely is what Query Monitor can’t be: an answer in real human terms, with a specific next step.
Query Monitor is built for developers who can read what it shows. That’s both its strength and its limit.
A free WordPress plugin with 1 million+ active installs. It adds a debugging panel to the admin toolbar showing developers everything that happened during a page load: every database query executed, every PHP error thrown, every HTTP API call made, every hook fired, every script and stylesheet loaded. For a developer debugging a WordPress site, it’s the most comprehensive tool available.
The Queries panel shows the full SQL for every database call, which plugin triggered it, how long it took, and whether it was slow or duplicated. The PHP Errors panel shows notices, warnings, and fatal errors with full stack traces and the exact file and line that caused them. The Hooks panel shows every WordPress action and filter that fired, in order. The amount of data is genuinely impressive.
Reading it requires knowing what you’re looking at. A PHP fatal error tells you a class wasn’t found on line 247 of a file inside a plugin you’ve never opened. A slow query tells you a SELECT ran in 480ms, returning 1,200 rows. Each of these tells a developer exactly what to do next. For a site owner who didn’t write the code and doesn’t recognize the file names, the panel is a wall of data without an exit.
Query Monitor shows you what’s happening. It doesn’t tell you why it matters, which part of it caused your checkout to stop working, or what to do next. That translation is what Loupely is built to do.
Your checkout stopped processing after yesterday’s plugin update.
Same failure. Same moment. Here’s what each tool gives you.
You can see a fatal error in the Stripe plugin. But which update caused it? Is it the Stripe plugin or WooCommerce? Is it safe to roll back? Who do you contact?
You know what caused it, which plugin to roll back, the exact step to take, and who to contact. No PHP knowledge needed.
Query Monitor is for developers who can interpret raw data. Loupely is for everyone who can’t.
| Capability | Query Monitor | Loupely | |
|---|---|---|---|
| Shows PHP errors occurring during a page load | |||
| Attributes errors to the responsible plugin or theme | |||
| Captures failed HTTP API calls to external services | |||
| Correlates what the browser saw with what the server logged — together in one capture | |||
| Real human terms explanation: exactly what broke and why | |||
| Specific next step: roll back, contact host, contact plugin developer, or fix yourself | |||
| Automatic state snapshot before every plugin change — know exactly what updated before the failure | |||
| Always-on monitoring: alerts you when something breaks, not when you happen to check | |||
| Developer handoff file: everything a developer needs without follow-up questions | |||
| Works without knowing what a PHP fatal error, stack trace, or database query means |
Query Monitor is the right tool. Just not for this person.
The data in both tools comes from the same WordPress installation. The difference is what happens to it after you see it.
You’re a developer who works in WordPress daily
Query Monitor is the right tool for developers optimizing database queries, debugging hook conflicts they introduced, auditing plugin performance, or building custom themes. It’s comprehensive, fast, free, and has no equal for someone who can read a stack trace and knows what a slow query means.
Your checkout is down and you don’t know which plugin caused it
You updated 3 plugins last night. This morning a customer texted that they couldn’t check out. You opened Query Monitor, saw a PHP fatal with a file name you don’t recognize, and had no idea whether to deactivate that plugin or call your host. Loupely picks up exactly there: browser and server captured together, the cause named, and a specific step to take.
You’re sending a bug report to a developer or your host
A description of the problem gets you a generic response. A Loupely capture file gets you a fix. It contains every browser event, every server log, every plugin state, and what Loupely believes caused it. Your developer or host can write the fix on the first pass, not after two rounds of “can you send a screenshot?”
It shows you what’s wrong. It doesn’t survive when your site goes down.
Query Monitor is inaccessible when your site experiences a fatal PHP error or crashes entirely — the exact moment you need debugging data most. It has no persistent history, so intermittent failures leave no trace. And it stores no data outside the current page load, so by the time you open the admin bar, whatever broke may already be gone.
Install the plugin. Install the extension. When something breaks, run a capture.
One click triggers both sides at once: the browser captures what it saw, the plugin captures what the server logged. They come back together in one file.
Install the plugin and extension. About 5 minutes.
The WordPress plugin goes in your site’s plugin directory. The Chrome extension goes in your toolbar. Once connected, Loupely starts recording state snapshots automatically — before every plugin change, and every 6 hours as a baseline. Free to install, no account required to capture.
When something breaks, click Capture.
One click. The extension reads what the browser experienced. The plugin reads what the server logged: PHP errors, database queries, failed HTTP calls, active plugins, your WordPress and PHP versions. Both sides are correlated by timestamp into one structured file.
Read the answer. Act on it or send it.
The popup tells you what broke in real human terms, routes you to the right next step, and pre-writes the message to send your developer or host if you need one. The capture file is always free to download — your developer has everything they need from it before asking a follow-up question.
What the visitor’s browser saw
Console errors, failed network requests, JavaScript exceptions, page load state, and what the browser received back from the server — timestamped and structured. Query Monitor never sees this side.
What WordPress logged on the server
PHP errors, failed outgoing HTTP requests, active plugins and their versions, WordPress version, PHP version, WooCommerce status, and recent fatal events — all recorded persistently, not just for the current page load.
What your site looked like before it broke
Automatic snapshots taken before every plugin activation, deactivation, or update. When the failure happens, Loupely can tell you: your site was healthy at 9am, plugin X updated at 9:02am, errors started at 9:03am.
Browser and server read together
15 correlation rules match browser events to server events. A JavaScript exception on the checkout page correlated with a fatal PHP error in a payment plugin at the same timestamp tells a complete story that neither side can tell alone.
Common questions about Loupely vs. Query Monitor.
Should I uninstall Query Monitor if I install Loupely?
No. If you use Query Monitor actively and can read what it shows, keep it. They do different things for different purposes. Loupely is built for the moment Query Monitor stops being useful — when you open the error panel, see PHP notices with file paths you don’t recognize, and have nowhere to go from there. Both can be installed at the same time, though for performance reasons Query Monitor should be deactivated when you’re not actively using it.
Query Monitor is free. Why would I pay for Loupely?
Query Monitor is free because it gives you raw data and asks you to do the work of interpreting it. The interpretation is what you’re buying with Loupely — knowing which of those PHP errors caused your checkout to fail, and what to do about it specifically. The capture is always free. One credit ($1.90) buys the diagnosis. At that price, a single avoided developer hour covers the cost of many diagnoses.
Query Monitor can’t run when my site is down. Does Loupely have the same problem?
Partly. Loupely’s Black Box feature writes crash snapshots to a flat file as a fallback when the database is unreachable, so it captures state even through some fatal failures. And because Loupely records state snapshots before every plugin change, you often have the evidence you need from before the crash — without needing the admin bar to be accessible during the failure.
What does “browser and server together” mean and why does it matter?
Query Monitor only sees the server. It never sees what the browser experienced: the console errors, the failed network requests, what actually loaded (or didn’t) on the page. Many failures only make sense when both sides are read together. A form that silently stops submitting may show nothing in Query Monitor if the failure is a JavaScript error catching the submission before it ever reaches the server. Loupely sees both.
I’m going to hand this off to a developer anyway. Why not just send them Query Monitor output?
A screenshot of Query Monitor output tells your developer what the PHP panel shows right now, on one page load, without browser context, without plugin state history, and without a correlation between the error and the browser behavior. A Loupely capture file gives your developer the complete picture: browser, server, plugin history, and what Loupely believes caused it. The difference is whether your developer can write the fix on the first reply or needs 3 more rounds of “can you also check…”
Does Loupely monitor my site automatically?
Yes. Once installed, Loupely runs a heartbeat every 5 minutes and sends an email alert within 20 minutes of detecting a failure. Query Monitor only shows you what’s happening when you’re actively looking at the admin bar. Loupely tells you when something breaks while you’re not watching — which is when most site failures actually happen.
What’s the difference between Loupely and Loupely Lens?
They solve different problems. Loupely handles functional failures: checkout down, form not sending, login failing. It requires the WordPress plugin. Loupely Lens handles visual failures: button wrong color, section won’t center, text overlapping on mobile. It’s a Chrome extension that works on any website. One account, one credit pool.
A website can fail in two ways. Something stops working. Something looks wrong.
Loupely and Loupely Lens cover opposite ends of what can go wrong. One account, one credit pool.
Something stopped working.
Checkout down. Form not sending. Login failing. Plugin conflict after an update. Loupely reads browser and server together, records your site state before every change, monitors around the clock, and delivers the diagnosis in real human terms with a specific next step. WordPress.
Something looks wrong.
Button wrong color. Section won’t center. Text overlapping on mobile. Lens clicks on what looks wrong, reads the full CSS cascade, and tells you what’s causing it and what to change — or writes the file to send your developer. Any website in Chrome.
Query Monitor opened. Nowhere to go with it. Loupely picks up there.
Free to install. Free to capture. One credit for the diagnosis. Always-on monitoring included.