Redirect monitors

What it checks

A redirect monitor opens a URL in a real browser, as a visitor would, lets it follow wherever it's sent, and compares the address it ends up on with the one you expect. It's for addresses whose whole job is to send people somewhere else: an old domain pointing at the new one, http:// to https://, a campaign or short link, a page that moved.

The address is read once the page has finished loading. The check identifies itself as an ordinary Chrome browser, so it's sent wherever a Chrome visitor would be.

Adding one

Under Monitors, choose Add Monitor, then Redirect, and enter:

• URL - the address to start from, including http:// or https://.
• Expected URL - where it should end up. The monitor is down when it lands anywhere else.

Once there's an Expected URL, choose how much of it has to match:

• Compare Sub-Domain - the whole host has to match, www. included.
• Compare Path - the path has to match too. A trailing slash makes no difference.
• Compare Query and Fragment - the query string and the # fragment have to match as well.

All three start off. With none on, the landing address only has to have the same scheme (https or http) and the same domain - https://shop.example.com/sale matches an expected https://www.example.com. The scheme and the domain are always compared.

To add several at once, choose Add several at once and paste one URL per line; each is checked against the same Expected URL.

How often

Opening a page in a browser is heavier than a plain request, so a redirect monitor is checked at most once an hour, on every plan, and as rarely as once a day. Mon chooses where the check runs from. The Timeout - 10 seconds to start with - is how long the page has to finish loading.

What it reports

State	Meaning	Monitor
Matched	Landed on an address that matches the Expected URL	Up
URL mismatch	Landed somewhere else	Down
Didn't load	The page couldn't be opened, or didn't finish loading within the timeout	Down

The monitor's page shows where it starts, where it should land, and where the last check did land, with a tick or a cross.

The status code of the page it lands on isn't checked: a redirect that arrives at the right address is up, even if that page then answers with an error. Watch the destination itself with an HTTP monitor.

A down redirect monitor raises a Monitor Down alert on its contacts - by default on the 1st failed check - and a Monitor Up alert when it lands correctly again. See Alerts and contacts.

Redirect monitors and HTTP monitors

An HTTP monitor can check an Expected URL too, with the same three comparisons. It makes a plain request instead of opening a browser: it follows the server's redirects, follows JavaScript and <meta> redirects only when you switch them on, checks the status code of the page it lands on, and can be checked every minute from the locations you choose. Use an HTTP monitor when the destination's status code and speed matter, and a redirect monitor when you want to see where a visitor's browser really ends up.

Redirect monitors are on every plan.