In the core's response.go, add an optional RedirectCodeSetter field or variadic use303 ...bool parameter to Redirect() and use the stored code + http.StatusSeeOther in core.go instead of the hardcoded http.StatusTemporaryRedirect, so that a POST handler can redirect to a GET route by calling c.Response.Redirect("/url", true).

core.go

@@ -308,7 +308,11 @@ func (app *App) makeHTTPRouterHandlerFunc(h Controller, ms []Hook) httprouter.Ha
 			w.WriteHeader(ctx.Response.statusCode)
 		}
 		if ctx.Response.redirectTo != "" {
-			http.Redirect(w, r, ctx.Response.redirectTo, http.StatusTemporaryRedirect)
+			statusCode := ctx.Response.redirectStatusCode
+			if statusCode == 0 {
+				statusCode = http.StatusTemporaryRedirect // default to 307
+			}
+			http.Redirect(w, r, ctx.Response.redirectTo, statusCode)
 		} else {
 			w.Write(ctx.Response.body)
 		}

response.go

@@ -20,6 +20,7 @@ type Response struct {
 	overrideContentType string
 	isTerminated        bool
 	redirectTo          string
+	redirectStatusCode  int
 	HttpResponseWriter  http.ResponseWriter
 }
 
@@ -136,8 +137,10 @@ func (rs *Response) ForceSendResponse() {
 	rs.isTerminated = true
 }
 
-// updates the redirect URL for the response and returns the modified Response. Validates the URL before setting it.
+// Redirect sends a redirect response to the given URL.
-func (rs *Response) Redirect(url string) *Response {
+// By default it uses 307 (Temporary Redirect) to preserve the HTTP method.
+// Pass true as the second argument to use 303 (See Other), which changes POST to GET.
+func (rs *Response) Redirect(url string, use303 ...bool) *Response {
 	validator := resolveValidator()
 	v := validator.Validate(map[string]interface{}{
 		"url": url,
@@ -153,6 +156,13 @@ func (rs *Response) Redirect(url string) *Response {
 		return rs
 	}
 	rs.redirectTo = url
+
+    if len(use303) > 0 && use303[0] {
+        rs.redirectStatusCode = http.StatusSeeOther  // 303
+    } else {
+        rs.redirectStatusCode = http.StatusTemporaryRedirect  // 307 (default)
+    }
+
 	return rs
 }