Extensions
FG Offline IP Whitelist opens maintenance mode to trusted IPs
Joomla's maintenance screen normally makes even routine front-end checks an administrator task; this free plugin is aimed at a narrower access exception.
It lets visitors from configured IP addresses bypass Joomla's Site Offline screen while the site remains offline for everyone else.
This situation comes up when a team needs to check the public-facing site during maintenance without opening it to the public. Joomla core already has an offline mode and permits users with the core.login.offline permission to get past it, normally through a Super User login on the offline screen. Core does not provide an IP allowlist for that purpose. A template override could change the screen's wording or appearance, but not the underlying access check, so this is the kind of gap that leads to a system plugin. According to the listing, this one goes beyond core with exact IPv4 and IPv6 entries, CIDR ranges, optional handling of selected proxy or CDN headers, and optional Joomla logging of bypasses.
It is intended for site owners, agencies, or maintenance teams that use fixed office addresses, VPN endpoints, or a controlled proxy while working on a live Joomla site. A site that rarely enters offline mode, has only one administrator, or is happy to use Joomla's existing login path has little reason to install it.
The listing marks it as a free download under GPLv2 or later and says it supports Joomla 4, 5, and 6. The developer is ferino; the directory shows eight other extensions from that developer, but this listing has no reviews. Before installing, check how your proxy setup supplies client IPs, what happens when an address changes, and how misconfiguration could expose the site. The listing does not explain support or maintenance terms, independent security testing, or detailed failure and recovery behaviour.
Listed on the Joomla Extensions Directory.