If you trying to Install Magento in your local system using XAMPP. Definitely your Readiness Check will produce error in PHP Extensions Check failed.
Solution :
1. Go to XAMPP (folder) -> PHP (folder) -> php.ini
2. Search ;extension=php_intl.dll
3. Remove semicolon from above. It would be like extension=php_intl.dll
4. Save and close php.ini
5. Restart Apache from XAMPP
nerdyJune 8, 2020 
nerdyMay 6, 2020 
nerdySeptember 2, 2017 
Thanks for sharing this post Bro, seriously it helps me lot.
Thanks for sharing this post Bro, seriously it helps me lot.