<html> <head> </head> <body bgcolor="#000000"> <font color="#FF0000" face="arial"> <center> screw you guys! i'm going home :P </center> </font> </body> </html>
You can type viewhtmlonline.com in front of any url you're browsing and it will show you the source.
viewhtmlonline.com
For example: viewhtmlonline.com/https://temp.cool
viewhtmlonline.com/https://temp.cool