Global redirects
A global redirect sends every request on a domain to one destination, no matter the path. It's the simplest possible rule, and the right tool when you're redirecting an entire site rather than individual pages.
What a global rule is
A global rule has no path of its own, it matches everything on the domain it's set on. It's typically the first rule people create when migrating a whole site to a new domain, since it covers every URL without needing to map each one individually.
Setting one up
Type * into Old URL when creating a rule, and it's automatically detected and labeled Global. When editing an existing rule, there's also a "Global fallback" checkbox that fills in * for you. See Creating a Redirect for the full form walkthrough.
One per domain
This limit applies only to the global * rule itself. Each domain can have exactly one, since * is a single, unique path value, trying to create a second is blocked with "A rule for this path already exists." If you need to change where the catch-all points, edit the existing global rule rather than creating a new one.
This doesn't limit your other rules at all, you can still create as many path rules as you need on the same domain, exact paths like /about, or wildcard prefixes like /blog/*. The one-per-domain limit is specific to the * global fallback, not to redirects in general.
Scope: isolated per domain
A global rule only applies to the domain entry it's set on, apex domains and their www variant are covered together, since that's one entry. It has no effect on subdomains, since each subdomain is added and managed as a fully separate domain with its own independent rule set. A global rule on example.com won't touch store.example.com at all, that subdomain needs its own rules if you want it redirected too.
Common use cases
The most common one is a full domain migration, point everything from an old domain to a new one with a single 301. It's also useful for a temporary maintenance redirect (302, pointing to a status page while you work on something), or for domain parking, sending an unused domain to your main site.
Priority: last resort
A global rule only fires when nothing more specific matches. Any path rule, exact or prefix, on the same domain takes priority over it. See Path Redirects for how that priority order works in detail.