360 Orbit Speed Optimizer

That is exactly what the safe .htaccess mode protects against: before every change, the previous block is backed up automatically, and afterwards the homepage is requested once. If it responds with a server error, the change is rolled back automatically, without any action on your part.

It requests one page of your own website, like a visitor would, and measures that single request. The request carries a one-time key that is valid for five minutes. The result is saved by your server, not sent back in the answer. Nothing leaves your server.

No. It only measures when you click “Start check” or switch on measuring for your browser (which ends by itself after 60 minutes). When it is not measuring, it does not hook into your pages and costs no database queries. While measuring, the request takes a little longer than normal, so the numbers are slightly above everyday operation. Visitors are never measured.

No. It only gives advice. A setting changes only when you click “Fix now” and confirm. Changes to .htaccess go through the safe mode: backup first, self-test afterwards, automatic rollback if your site stops answering.

It measures the server side: how long your server needs to build a page. It does not measure what happens in the visitor’s browser (layout shifts, image sizes, rendering); for that, use a browser tool. Plugins that load before the Performance Doctor itself are not included in the measurement. Visitors on other devices, other pages and other times of day may see different numbers.

A password protection, a firewall, maintenance mode or a host that does not allow a site to call itself can stop the automatic check. The message says which one. You can then measure by hand: switch on “Measure this browser” in the Performance Doctor tab, click through the slow pages as an administrator and click “Evaluate”.

The .htaccess block written by the plugin is removed automatically on deactivation, and the website then runs as it did before the installation.

The admin area follows the language set in WordPress. Translations are provided through translate.wordpress.org and you are welcome to contribute one for your language.