Fake news is not news you disagree with -- it is content generated by non-news organizations to drive eyeballs to ads (e.g., clickbait) or to spread false information (rumors, conspiracy theories, junk science, and propaganda, for example).
First Things to Look For:
1. Websites created to look like familiar mainstream news sites, e.g. "Boston Tribune."
Look for contact information with a verifiable address and affiliation.
Look for an About page, often in the header or footer of the home page. Read the About page closely for evidence of partisanship or bias. If there's no About page and no Contact page, be very skeptical.
In staff listings (or on the About page), look critically at the list of executives. Are they real people or stock photos? Open a new tab and look for another profile of the individual (e.g. LinkedIn).
Perform an independent search for the news source. Compare and verify URLs. Example: http://abcnews.com.co/ (fake site) is not the ABC Network News http://abcnews.go.com, but the logo and the URL are almost identical.
2. Advertisements designed to look like news stories: "native advertising".
Look for labels: a corporate logo. Or a tiny statement indicating Paid Post, Advertisement, or Sponsored by. Or the tiny Ad Choices triangle at the upper right corner of an image.