MDN’s new design is in Beta! A sneak peek:

Web content's origin is defined by the scheme (protocol), host (domain), and port of the URL used to access it. Two objects have the same origin only when the scheme, host, and port all match.

Some operations are restricted to same-origin content, and this restriction can be lifted using CORS.

Examples of same origin
same origin because same scheme (http) and host (
same origin because a server delivers HTTP content through port 80 by default

Examples of different origin
different schemes
different hosts
different ports

Learn more

​See Same-origin policy for more information.

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 Contributors to this page: Sheppy, teoli, Andrew_Pfeiffer, wbamberg, Biraj, Jeremie, rebloor
 Last updated by: Sheppy,