Can I Set Cookies for External Domains?

Setting Cookies for External Domains: A Security Limitation

A common misconception in web development is the ability to set cookies for other domains. In reality, it is not possible due to strict security measures.

When a browser reads a cookie set by a specific domain, it follows the same-origin policy, which prevents it from sending that cookie along with requests to other domains.

This security feature is crucial to protect user privacy and prevent malicious websites from exploiting valuable information. Browser security protocols ensure that websites can only access cookies they have explicitly set, thus mitigating potential risks of cross-domain tracking or data theft.

Therefore, if you wish to set a cookie for a different domain, you must request that the target domain sets the cookie themselves. One solution is to employ a redirect mechanism.

By redirecting users to the target domain with a predefined "Set Cookie" request, you can prompt the target domain to set the desired cookie. The user will then be redirected to the intended landing page on the target domain with the cookie successfully set.

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