Why does my POST request lose its body when redirected with 301 or 302?

Browsers historically change POST to GET when following 301 and 302 redirects, dropping the request body in the process. While the HTTP spec originally said 302 should preserve the method, every browser implemented it as POST-to-GET, and 301 followed the same convention. This ambiguity is why 307 and 308 were created: they explicitly require the method and body to be preserved. If you need to redirect a POST and keep the body, use 307 (temporary) or 308 (permanent).

What is the difference between 307 and 302 redirects?

The key difference is method preservation. A 302 allows browsers to change POST to GET (and all browsers do). A 307 requires the browser to use the exact same method: a POST stays a POST, a PUT stays a PUT, and the request body is resent to the new URL. Both are temporary redirects that are not cached and tell search engines to keep the original URL in the index. Use 307 when method preservation matters (API endpoints, form submissions that must reach a different server), and 302 when the redirect is temporary and GET is acceptable.

How does the choice of redirect status code affect SEO?

301 and 308 (permanent) transfer nearly all link equity (PageRank) to the new URL, and search engines eventually replace the old URL with the new one in their index. 302 and 307 (temporary) tell search engines to keep the original URL indexed and pass link equity only temporarily. If a 302 is left in place for many months, Google may eventually treat it as a 301. The worst SEO mistake is using 302 for permanent moves, as it delays search engine consolidation, or using 301 for temporary changes, as the cached redirect persists in browsers even after you remove it.

When should I use 303 See Other instead of 302 Found?

Use 303 after a state-changing operation (POST, PUT, DELETE) when you want to redirect the user to a result page via GET. This is the Post-Redirect-GET pattern: the user submits a form (POST), the server processes it and responds with 303 pointing to a confirmation page (GET). If the user refreshes the confirmation page, they send a GET, not a duplicate POST. 303 is explicit about always using GET, while 302's method behavior is technically undefined (though browsers treat it the same way). Use 303 when you specifically intend the redirect to switch to GET.

Does Internet Explorer support all redirect status codes?

IE11 supports 301, 302, 303, and 307 correctly. It does NOT support 308 Permanent Redirect; IE11 treats a 308 response as an error and does not follow the redirect. If you need to support IE11, use 301 instead of 308 for permanent redirects (accepting that POST may change to GET). All modern browsers (Chrome, Firefox, Safari, Edge) fully support all five redirect codes including 308. Since IE11 reached end of life in June 2022, 308 is safe for virtually all current web traffic.

Differentiating Redirect Status Codes