A good way to check how biased a source is

For example:

https://mediabiasfactcheck.com/politico/

https://mediabiasfactcheck.com/the-sun/

https://mediabiasfactcheck.com/daily-mail/

https://mediabiasfactcheck.com/foreign-affairs/

https://mediabiasfactcheck.com/the-guardian/

https://mediabiasfactcheck.com/the-economist/

https://mediabiasfactcheck.com/daily-telegraph/