For an unexplained reason, Apple has removed its iCloud Activation lock checker off of its iCloud web page. The tool used to exist on iCloud.com/activationlock but now redirects to a 404 page.
The utility allowed you to type in an IMEI or serial number of an iOS device to figure out if it was Activation Locked. This was especially useful for anyone who purchased a used iOS device online and would let you check it before purchasing.
In addition, references to the tool has been removed from Apple support pages, indicating that it’s not being temporary removed and will be a more permanent change.
Previously, this link would tell you more about the tool but has since been removed since January 24. The iCloud.com/activationlock link stopped working sometime this morning.
Now, it’s currently impossible to check the status of the Activation Lock without obtaining the device physically. It’s also unclear if Apple will replace this tool in the future.
Activation Lock was introduced in iOS 8 and has been enabled by default on every iOS device since. This makes it impossible for a theft to use the device without the Apple ID and password of the original owner.