The code of the website is to blame. It includes a very long string of characters, which are difficult or impossible for the browser to process.
This is likely to result in a memory issue for the device, which causes it to crash.
Even people who are wised up to the website, or see the clue in the name, aren’t safe.
Pranksters are using link shorteners to disguse the real link, which means that any unknown link could contain the crashsafari website.

iPhone users in particular should be careful about clicking on unknown links for the near future.
If you accidentally click the link, don’t worry, the device will usually behave normally after a reboot.
Last year, pranksters played the ‘effective power’ trick on iPhone users.
It was even more malicious than crashsafari, as anyone who opened a message containing the special code suffered from constant iPhone reboots.
The messages, when sent from an iPhone to another iPhone, caused the receiver’s device to crash instantly when opened.
At the time, Apple released a statement on how to fix affected phones,telling users to open Siri, tell Siri to mark all messages as read and reply to the malicious message.