About this plugin
Crash alerts
” The real error is hidden, so you don’t know which plugin or theme caused it.
With crash alerts on (1 Preventionlabs credit a day), you get an email when your site crashes. It says:
- Which plugin or theme broke the site, by name (for out-of-memory and time-limit crashes: which one was running).
- What went wrong. For example: it ran out of memory, a file has broken code, or it needs code that isn’t on your site.
- Whether that plugin was updated or turned on shortly before the crash, with the version and how long before.
- How to fix it, including what to do if you can’t log in.
A real alert, from a test site:
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Acme Shop crashed your site.
The plugin Acme Shop tried to use a piece of code (acme_missing_helper) that isn’t on your site. This usually means it needs another plugin that is turned off or missing, or it doesn’t match your WordPress or PHP version. 0, 1 minute before the crash, so the update is the most likely cause.
How to fix it: Turn off Acme Shop. In your dashboard, go to Plugins and click Deactivate under it. If you can’t log in, open your host’s file manager and rename the folder wp-content/plugins/acme-shop to acme-shop-off.
If Acme Shop caused the crash, that brings your site back.
How it works:
- It uses WordPress’s own crash handler (the wp-content/fatal-error-handler.php drop-in), which loads before any plugin. So it also catches crashes in plugins that load before this one. If another plugin already uses that file, or WordPress can’t write to wp-content, it catches crashes after plugins load, and the plugin’s page tells you so.
- Every 10 minutes it checks your PHP error logs for new crashes and database errors. WordPress runs scheduled tasks when someone visits the site, so on a quiet site the check waits for the next visit.
- The same crash is emailed at most once every 6 hours, not once per visitor.
- WordPress’s own error page and recovery email work as before. Sending the report can delay the error page by up to 3 seconds, at most once per crash every 5 minutes.
What it can’t catch:
- Anything that stops WordPress before it loads: a broken wp-config.php, a database that’s down, or a server that’s down. For those, the uptime check covers you: once this site is verified, Preventionlabs checks it every 5 minutes, and emails you if the site fails two checks in a row (1 credit a day).
- A crash on a site where alerts were off. The plugin has to be on before the crash.
- A crash on a host that blocks outgoing connections. The error can’t be sent.
- Multisite networks. Crash alerts can’t be turned on there yet, because every site in a network shares the same crash handler and error logs.
Full report
One click checks your site from the outside, the way visitors, Google and email providers see it. It takes 15 seconds to about a minute and lists what’s broken, where, and what to do.
It checks:
- Pages: errors, slow pages, redirects, pages hidden from Google, broken links, JavaScript errors.
- Security: leaked files such as.env,.git and backups, outdated scripts with known security holes, security headers.
- Uptime and speed: HTTPS, redirects, page weight, caching.
- Search: noindex tags, robots.txt blocks, sitemap pages that fail.
- Email: SPF, DKIM and DMARC, which decide whether your emails land in spam.
- Domain and DNS: DNSSEC, nameservers, records pointing at services that no longer exist.
- WordPress: versions and plugins visible from outside.
Every check is read-only: the checks can’t change your site, DNS, code or settings. ) Reports are made by code from what was checked, not by AI. You can copy a report into an AI assistant or send it to your developer.
Only a site’s owner can check it. The plugin proves the site is yours in one click, with no DNS changes.
au. au/checks.
External services
au. Reports and crash explanations are made on Preventionlabs’ servers, not on your site.
- Reports: your Preventionlabs API key, this site’s address (when you click Verify this site), and the ID of the site you choose to check. Sent when an administrator clicks Connect, Verify this site or Run full check, and each time the Tools > Preventionlabs page is opened (to list your sites).
- Uptime check: once this site is verified, Preventionlabs requests its home page every 5 minutes, as any visitor would, and emails you if it fails two checks in a row (1 credit a day). Turn these emails off on the Health page in your Preventionlabs dashboard.
- The proof: when you click Verify this site, the plugin publishes a random token at /?rest_route=/preventionlabs/v1/proof. Preventionlabs reads it to confirm the site is yours, when you verify and before each report. It only proves this site to your account. It is removed when you delete the plugin.
- Crash alerts, only after an administrator clicks Turn on crash alerts: when the site crashes, the error message, file and line, the page address without its query string, and the names and versions of the active plugins and theme. Every 10 minutes, new crash and database error lines from the PHP error logs WordPress can read. Before sending, folder paths on your server are replaced with wp-content/…, values passed to functions are removed from stack traces, and database queries are removed from database errors. Nothing else from the logs is sent. Errors are sent with a token made for this site, which can only send errors for it. Each error is kept until 30 days after it was last seen, and emailed to your Preventionlabs account’s email address.
- The crash catcher: turning crash alerts on adds the file wp-content/fatal-error-handler.php. Turning them off, or deactivating or deleting the plugin, removes it. If another plugin already uses that file, it is left alone.
- Terms: https://preventionlabs.com.au/terms. Privacy policy: https://preventionlabs.com.au/privacy.
A Preventionlabs account is required. Price:
- Free to sign up, with 2 free full reports on each domain.
- US$28 a month for 1,500 credits a month (they reset each month). Cancel any time.
- A full report is 1 credit. Crash alerts and uptime checks are 1 credit a day each, per site. Reading reports is free.
- Subscribers can buy more credits at 10 US cents each, from US$20. Bought credits never expire.
- When credits run out, alerts pause until credits come back. You get an email at 25 credits left.