Tick one checkbox and your site is hidden behind an Under Construction page. Visitors see your holding page; you and anyone you let through see the real site. That is the whole plugin.

Two ways to get past the page without logging in:

A secret word. Visit yoursite.com/?yoursecret once and a cookie keeps that browser through. Good for showing a client work in progress.
An IP whitelist. Your office, your phone, an uptime monitor — they always see the live site.

Logged-in users are never blocked, and /wp-admin, the REST API, WP-CLI and cron keep working normally.

The page itself is your HTML. Paste in a full document with DOCTYPE, <style> and <body> if you want, or a single line of text. No page builder, no template picker, no upsell wizard — no settings you have to learn before the plugin does its job.

Use it for

Coming soon pages for a site that has not launched yet.
Maintenance mode while you rebuild, migrate or debug.
Staging and client-preview sites you want off the public web and out of Google.

Settings

Go to the settings page in Settings > Really Simple Under Construction. Enable by checking the checkbox. The Under Construction page is only visible to visitors who are not logged in. You can optionally configure:

The Under Construction page itself — paste any HTML (DOCTYPE, <style>, <body> etc. are supported, scripts are stripped).
A secret word that lets you bypass the page via a URL like ?yoursecret. A cookie is then stored so the same browser keeps access.
The lifetime of that cookie, in days.
A list of IP addresses to whitelist for users and services that should always see the real site.

Really Simple Under Construction Page – Coming Soon & Maintenance Mode

Use it for

Settings