redirect defaults to 303

CHANGES.rst

@@ -16,6 +16,11 @@ Unreleased
     deprecation period. :issue:`5815`
 -   ``template_filter``, ``template_test``, and ``template_global`` decorators
     can be used without parentheses. :issue:`5729`
+-   ``redirect`` returns a ``303`` status code by default instead of ``302``.
+    This tells the client to always switch to ``GET``, rather than only
+    switching ``POST`` to ``GET``. This preserves the current behavior of
+    ``GET`` and ``POST`` redirects, and is also correct for frontend libraries
+    such as HTMX. :issue:`5895`
 
 
 Version 3.1.2

docs/api.rst

@@ -596,7 +596,7 @@ This specifies that ``/users/`` will be the URL for page one and
 ``/users/page/N`` will be the URL for page ``N``.
 
 If a URL contains a default value, it will be redirected to its simpler
-form with a 301 redirect. In the above example, ``/users/page/1`` will
+form with a 308 redirect. In the above example, ``/users/page/1`` will
 be redirected to ``/users/``. If your route handles ``GET`` and ``POST``
 requests, make sure the default route only handles ``GET``, as redirects
 can't preserve form data. ::

src/flask/helpers.py

@@ -239,7 +239,7 @@ def url_for(
 
 
 def redirect(
-    location: str, code: int = 302, Response: type[BaseResponse] | None = None
+    location: str, code: int = 303, Response: type[BaseResponse] | None = None
 ) -> BaseResponse:
     """Create a redirect response object.
 
@@ -252,6 +252,9 @@ def redirect(
     :param Response: The response class to use. Not used when
         ``current_app`` is active, which uses ``app.response_class``.
 
+    .. versionchanged:: 3.2
+        ``code`` defaults to ``303`` instead of ``302``.
+
     .. versionadded:: 2.2
         Calls ``current_app.redirect`` if available instead of always
         using Werkzeug's default ``redirect``.

src/flask/sansio/app.py

@@ -932,7 +932,7 @@ def should_ignore_error(self, error: BaseException | None) -> bool:
         """
         return False
 
-    def redirect(self, location: str, code: int = 302) -> BaseResponse:
+    def redirect(self, location: str, code: int = 303) -> BaseResponse:
         """Create a redirect response object.
 
         This is called by :func:`flask.redirect`, and can be called
@@ -941,6 +941,9 @@ def redirect(self, location: str, code: int = 302) -> BaseResponse:
         :param location: The URL to redirect to.
         :param code: The status code for the redirect.
 
+        .. versionchanged:: 3.2
+            ``code`` defaults to ``303`` instead of ``302``.
+
         .. versionadded:: 2.2
             Moved from ``flask.redirect``, which calls this method.
         """