diff --git a/changelog.d/mediaproxy-content-type.fix b/changelog.d/mediaproxy-content-type.fix
deleted file mode 100644
index f36dd6283..000000000
--- a/changelog.d/mediaproxy-content-type.fix
+++ /dev/null
@@ -1 +0,0 @@
-Detect image content types for extensionless MediaProxy responses.
diff --git a/lib/pleroma/reverse_proxy.ex b/lib/pleroma/reverse_proxy.ex
index 12e48eadd..ee20303a3 100644
--- a/lib/pleroma/reverse_proxy.ex
+++ b/lib/pleroma/reverse_proxy.ex
@@ -17,7 +17,6 @@ defmodule Pleroma.ReverseProxy do
   @max_read_duration :timer.seconds(30)
   @max_body_length :infinity
   @failed_request_ttl :timer.seconds(60)
-  @sniff_bytes 8 * 1024
   @methods ~w(GET HEAD)
 
   @allowed_mime_types Pleroma.Config.get([Pleroma.Upload, :allowed_mime_types], [])
@@ -70,12 +69,7 @@ defmodule Pleroma.ReverseProxy do
   * `inline_content_types`:
     * `true` will not alter `content-disposition` (up to the upstream),
     * `false` will add `content-disposition: attachment` to any request,
-    * a list of whitelisted content types for which `content-disposition: inline`
-    is always set (overriding any upstream header) so the media can be embedded
-    in pages; the filename is derived from the content type
-
-  * `sniff_content_type` (default `false`): detects an image MIME type from the first
-  response chunk when the upstream type is missing or `application/octet-stream`.
+    * a list of whitelisted content types
 
   * `req_headers`, `resp_headers` additional headers.
 
@@ -112,7 +106,6 @@ defmodule Pleroma.ReverseProxy do
           | {:req_headers, [{String.t(), String.t()}]}
           | {:resp_headers, [{String.t(), String.t()}]}
           | {:inline_content_types, boolean() | list(String.t())}
-          | {:sniff_content_type, boolean()}
           | {:redirect_on_failure, boolean()}
 
   @spec call(Plug.Conn.t(), String.t(), list(option())) :: Plug.Conn.t()
@@ -228,30 +221,11 @@ defmodule Pleroma.ReverseProxy do
   defp response(conn, client, url, status, headers, opts) do
     Logger.debug("#{__MODULE__} #{status} #{url} #{inspect(headers)}")
 
-    case maybe_prefetch_for_content_type(headers, client, opts) do
-      {_headers, client, {:error, {:upstream, error}}} ->
-        Logger.warning(
-          "#{__MODULE__} request to #{url} failed before streaming: #{inspect(error)}"
-        )
-
-        client().close(client)
-        track_failed_url(url, error, opts)
-
-        conn
-        |> error_or_redirect(url, 500, "Request failed", opts)
-        |> halt()
-
-      {headers, client, prefetched} ->
-        stream_response(conn, client, url, status, headers, opts, prefetched)
-    end
-  end
-
-  defp stream_response(conn, client, url, status, headers, opts, prefetched) do
     result =
       conn
       |> put_resp_headers(build_resp_headers(headers, opts))
       |> send_chunked(status)
-      |> chunk_reply(client, opts, prefetched)
+      |> chunk_reply(client, opts)
 
     case result do
       {:ok, conn} ->
@@ -272,29 +246,18 @@ defmodule Pleroma.ReverseProxy do
     end
   end
 
-  defp chunk_reply(conn, client, opts, :none) do
+  defp chunk_reply(conn, client, opts) do
     chunk_reply(conn, client, opts, 0, 0)
   end
 
-  defp chunk_reply(conn, _client, _opts, :done), do: {:ok, conn}
-  defp chunk_reply(conn, _client, _opts, {:error, error}), do: {:error, error, conn}
-
-  defp chunk_reply(conn, client, opts, {:ok, data, duration}) do
-    with :ok <-
-           body_size_constraint(
-             byte_size(data),
-             Keyword.get(opts, :max_body_length, @max_body_length)
-           ),
-         {:ok, conn} <- write_chunk(conn, data) do
-      chunk_reply(conn, client, opts, byte_size(data), duration)
-    else
-      {:error, {:downstream, error}} -> {:error, {:downstream, error}, conn}
-      {:error, error} -> {:error, {:upstream, error}, conn}
-    end
-  end
-
   defp chunk_reply(conn, client, opts, sent_so_far, duration) do
-    with {:ok, data, client, duration} <- read_chunk(client, duration, opts),
+    with {:ok, duration} <-
+           check_read_duration(
+             duration,
+             Keyword.get(opts, :max_read_duration, @max_read_duration)
+           ),
+         {:ok, data, client} <- client().stream_body(client),
+         {:ok, duration} <- increase_read_duration(duration),
          sent_so_far = sent_so_far + byte_size(data),
          :ok <-
            body_size_constraint(
@@ -310,24 +273,6 @@ defmodule Pleroma.ReverseProxy do
     end
   end
 
-  defp read_chunk(client, duration, opts) do
-    result =
-      with {:ok, timer} <-
-             check_read_duration(
-               duration,
-               Keyword.get(opts, :max_read_duration, @max_read_duration)
-             ),
-           {:ok, data, client} <- client().stream_body(client),
-           {:ok, duration} <- increase_read_duration(timer) do
-        {:ok, data, client, duration}
-      end
-
-    case result do
-      {:error, error} -> {:error, {:upstream, error}}
-      result -> result
-    end
-  end
-
   defp write_chunk(conn, data) do
     case chunk(conn, data) do
       {:error, error} -> {:error, {:downstream, error}}
@@ -335,54 +280,6 @@ defmodule Pleroma.ReverseProxy do
     end
   end
 
-  defp maybe_prefetch_for_content_type(headers, client, opts) do
-    if Keyword.get(opts, :sniff_content_type, false) and generic_content_type?(headers) do
-      case read_chunk(client, 0, opts) do
-        {:ok, data, client, duration} ->
-          {maybe_put_image_content_type(headers, data), client, {:ok, data, duration}}
-
-        :done ->
-          {headers, client, :done}
-
-        {:error, error} ->
-          {headers, client, {:error, error}}
-      end
-    else
-      {headers, client, :none}
-    end
-  end
-
-  defp generic_content_type?(headers) do
-    headers
-    |> get_content_type()
-    |> String.trim()
-    |> String.downcase()
-    |> then(&(&1 in ["", "application/octet-stream"]))
-  end
-
-  defp maybe_put_image_content_type(headers, data) do
-    with false <- data == "",
-         {:ok, %{mime_type: "image/" <> _ = content_type}} <-
-           Majic.perform({:bytes, binary_part(data, 0, min(byte_size(data), @sniff_bytes))},
-             pool: Pleroma.MajicPool
-           ) do
-      [
-        {"content-type", content_type}
-        | Enum.reject(headers, fn {key, _} -> key == "content-type" end)
-      ]
-    else
-      _ -> headers
-    end
-  rescue
-    error ->
-      Logger.debug("#{__MODULE__}: content-type sniffing failed: #{Exception.message(error)}")
-      headers
-  catch
-    kind, reason ->
-      Logger.debug("#{__MODULE__}: content-type sniffing failed: #{kind}: #{inspect(reason)}")
-      headers
-  end
-
   defp head_response(conn, url, code, headers, opts) do
     Logger.debug("#{__MODULE__} #{code} #{url} #{inspect(headers)}")
 
@@ -430,33 +327,16 @@ defmodule Pleroma.ReverseProxy do
     |> build_req_range_or_encoding_header(opts)
     |> build_req_user_agent_header(opts)
     |> merge_headers(Keyword.get(opts, :req_headers, []))
-    |> maybe_force_identity_encoding(opts)
-  end
-
-  defp merge_headers(headers, extra_headers) do
-    Enum.reduce(extra_headers, headers, fn {key, value}, headers ->
-      List.keystore(headers, String.downcase(key), 0, {String.downcase(key), value})
-    end)
-  end
-
-  defp maybe_force_identity_encoding(headers, opts) do
-    if Keyword.get(opts, :sniff_content_type, false) do
-      List.keystore(headers, "accept-encoding", 0, {"accept-encoding", "identity"})
-    else
-      headers
-    end
   end
 
   # Disable content-encoding if any @range_headers are requested (see #1823).
   defp build_req_range_or_encoding_header(headers, _opts) do
     range? = Enum.any?(headers, fn {header, _} -> Enum.member?(@range_headers, header) end)
 
-    cond do
-      range? && List.keymember?(headers, "accept-encoding", 0) ->
-        List.keydelete(headers, "accept-encoding", 0)
-
-      true ->
-        headers
+    if range? && List.keymember?(headers, "accept-encoding", 0) do
+      List.keydelete(headers, "accept-encoding", 0)
+    else
+      headers
     end
   end
 
@@ -479,6 +359,12 @@ defmodule Pleroma.ReverseProxy do
     |> ensure_no_transform()
   end
 
+  defp merge_headers(headers, extra_headers) do
+    Enum.reduce(extra_headers, headers, fn {key, value}, headers ->
+      List.keystore(headers, String.downcase(key), 0, {String.downcase(key), value})
+    end)
+  end
+
   defp ensure_no_transform(headers) do
     {_, cache_control} =
       List.keyfind(headers, "cache-control", 0, {"cache-control", @default_cache_control_header})
@@ -568,20 +454,7 @@ defmodule Pleroma.ReverseProxy do
 
       replace_header(headers, "content-disposition", disposition)
     else
-      if opt == true do
-        headers
-      else
-        name = inline_filename(content_type)
-
-        disposition =
-          if name do
-            "inline; filename=\"#{name}\""
-          else
-            "inline"
-          end
-
-        replace_header(headers, "content-disposition", disposition)
-      end
+      headers
     end
   end
 
@@ -589,13 +462,6 @@ defmodule Pleroma.ReverseProxy do
     [{key, value} | Enum.reject(headers, fn {header, _} -> header == key end)]
   end
 
-  defp inline_filename(content_type) do
-    case MIME.extensions(content_type) do
-      [ext | _] when ext != "" -> "inline.#{ext}"
-      _ -> nil
-    end
-  end
-
   defp header_length_constraint(headers, limit) do
     lengths =
       for {"content-length", value} <- headers,
@@ -640,9 +506,7 @@ defmodule Pleroma.ReverseProxy do
     end
   end
 
-  defp check_read_duration(_, _), do: {:ok, :no_duration_limit}
-
-  defp increase_read_duration(:no_duration_limit), do: {:ok, :no_duration_limit}
+  defp check_read_duration(_, _), do: {:ok, :no_duration_limit, :no_duration_limit}
 
   defp increase_read_duration({previous_duration, started})
        when is_integer(previous_duration) and is_integer(started) do
diff --git a/lib/pleroma/web/mastodon_api/views/status_view.ex b/lib/pleroma/web/mastodon_api/views/status_view.ex
index 356e8fce5..4625be47c 100644
--- a/lib/pleroma/web/mastodon_api/views/status_view.ex
+++ b/lib/pleroma/web/mastodon_api/views/status_view.ex
@@ -631,7 +631,6 @@ defmodule Pleroma.Web.MastodonAPI.StatusView do
         String.contains?(media_type, "image") -> "image"
         String.contains?(media_type, "video") -> "video"
         String.contains?(media_type, "audio") -> "audio"
-        attachment["type"] == "Image" -> "image"
         true -> "unknown"
       end
 
diff --git a/lib/pleroma/web/media_proxy/media_proxy_controller.ex b/lib/pleroma/web/media_proxy/media_proxy_controller.ex
index 93f692008..a0aafc32e 100644
--- a/lib/pleroma/web/media_proxy/media_proxy_controller.ex
+++ b/lib/pleroma/web/media_proxy/media_proxy_controller.ex
@@ -208,7 +208,6 @@ defmodule Pleroma.Web.MediaProxy.MediaProxyController do
 
   defp media_proxy_opts do
     Config.get([:media_proxy, :proxy_opts], [])
-    |> Keyword.put_new(:sniff_content_type, true)
   end
 
   defp sandbox(conn, _params) do
diff --git a/test/pleroma/reverse_proxy_test.exs b/test/pleroma/reverse_proxy_test.exs
index bf0a809c4..156b7d7ed 100644
--- a/test/pleroma/reverse_proxy_test.exs
+++ b/test/pleroma/reverse_proxy_test.exs
@@ -579,56 +579,6 @@ defmodule Pleroma.ReverseProxyTest do
     assert Conn.get_resp_header(conn, "content-type") == ["application/octet-stream"]
   end
 
-  test "sniffs and preserves an image body with a generic content type", %{conn: conn} do
-    body = File.read!("test/fixtures/image.jpg")
-
-    ClientMock
-    |> expect(:request, fn :get, "/extensionless", headers, _, _ ->
-      assert {"accept-encoding", "identity"} in headers
-      {:ok, 200, [{"content-type", "application/octet-stream"}], %{body: body}}
-    end)
-    |> expect(:stream_body, fn %{body: ^body} = client ->
-      {:ok, body, Map.delete(client, :body)}
-    end)
-    |> expect(:stream_body, fn %{} -> :done end)
-
-    conn =
-      ReverseProxy.call(conn, "/extensionless",
-        sniff_content_type: true,
-        max_read_duration: :infinity,
-        req_headers: [{"accept-encoding", "gzip"}]
-      )
-
-    assert conn.resp_body == body
-    assert Conn.get_resp_header(conn, "content-type") == ["image/jpeg"]
-
-    assert Conn.get_resp_header(conn, "content-disposition") == [
-             "inline; filename=\"inline.jpg\""
-           ]
-  end
-
-  test "redirects a content sniffing failure before committing the response", %{conn: conn} do
-    url = "https://example.com/extensionless"
-
-    ClientMock
-    |> expect(:request, fn :get, ^url, _, _, _ ->
-      {:ok, 200, [{"content-type", "application/octet-stream"}], %{url: url}}
-    end)
-    |> expect(:stream_body, fn _ -> {:error, :closed} end)
-    |> expect(:close, fn _ -> :ok end)
-
-    conn =
-      ReverseProxy.call(conn, url,
-        sniff_content_type: true,
-        redirect_on_failure: true
-      )
-
-    assert conn.status == 302
-    assert Conn.get_resp_header(conn, "location") == [url]
-    assert conn.state == :sent
-    assert Cachex.get(:failed_proxy_url_cache, url) == {:ok, true}
-  end
-
   test "preserves a generic content type for a non-image body", %{conn: conn} do
     body = "not an image"
 
@@ -823,24 +773,6 @@ defmodule Pleroma.ReverseProxyTest do
       conn = ReverseProxy.call(conn, "/disposition")
 
       assert {"content-type", "image/gif"} in conn.resp_headers
-      assert {"content-disposition", "inline; filename=\"inline.gif\""} in conn.resp_headers
-    end
-
-    test "forces inline for inline content types overriding upstream attachment", %{
-      conn: conn
-    } do
-      disposition_headers_mock([
-        {"content-type", "image/png"},
-        {"content-disposition", "attachment; filename=\"filename.png\""},
-        {"content-disposition", "attachment; filename=\"duplicate.png\""},
-        {"content-length", "0"}
-      ])
-
-      conn = ReverseProxy.call(conn, "/disposition")
-
-      [disposition] = Conn.get_resp_header(conn, "content-disposition")
-      assert String.starts_with?(disposition, "inline")
-      refute String.starts_with?(disposition, "attachment")
     end
 
     test "with content-disposition header", %{conn: conn} do
@@ -853,50 +785,6 @@ defmodule Pleroma.ReverseProxyTest do
 
       assert {"content-disposition", "attachment; filename=\"filename.jpg\""} in conn.resp_headers
     end
-
-    test "with inline_content_types: true leaves upstream headers untouched", %{
-      conn: conn
-    } do
-      # opt == true: the proxy must not synthesise or rewrite content-disposition.
-      disposition_headers_mock([
-        {"content-type", "image/png"},
-        {"content-disposition", "attachment; filename=\"upstream.png\""},
-        {"content-length", "0"}
-      ])
-
-      conn = ReverseProxy.call(conn, "/disposition", inline_content_types: true)
-
-      assert {"content-disposition", "attachment; filename=\"upstream.png\""} in conn.resp_headers
-    end
-
-    test "forces bare inline for a whitelisted type with no MIME extension", %{
-      conn: conn
-    } do
-      # image/x-foo-bar has no entry in MIME's database, so inline_filename/1
-      # returns nil and the disposition should be the bare token "inline".
-      disposition_headers_mock([
-        {"content-type", "image/x-foo-bar"},
-        {"content-length", "0"}
-      ])
-
-      conn = ReverseProxy.call(conn, "/disposition", inline_content_types: ["image/x-foo-bar"])
-
-      [disposition] = Conn.get_resp_header(conn, "content-disposition")
-      assert disposition == "inline"
-    end
-
-    test "serves modern browser image types inline", %{conn: conn} do
-      disposition_headers_mock([
-        {"content-type", "image/webp"},
-        {"content-length", "0"}
-      ])
-
-      conn = ReverseProxy.call(conn, "/disposition")
-
-      assert Conn.get_resp_header(conn, "content-disposition") == [
-               "inline; filename=\"inline.webp\""
-             ]
-    end
   end
 
   describe "content-type sanitisation" do
diff --git a/test/pleroma/web/mastodon_api/views/status_view_test.exs b/test/pleroma/web/mastodon_api/views/status_view_test.exs
index 73adb196a..f7b815ed7 100644
--- a/test/pleroma/web/mastodon_api/views/status_view_test.exs
+++ b/test/pleroma/web/mastodon_api/views/status_view_test.exs
@@ -668,23 +668,6 @@ defmodule Pleroma.Web.MastodonAPI.StatusViewTest do
       assert expected == StatusView.render("attachment.json", %{attachment: object})
       assert_schema(expected, "Attachment", api_spec)
     end
-
-    test "uses the ActivityStreams image type when the MIME type is generic" do
-      object = %{
-        "type" => "Image",
-        "url" => [
-          %{
-            "mediaType" => "application/octet-stream",
-            "href" => "https://example.com/extensionless"
-          }
-        ]
-      }
-
-      attachment = StatusView.render("attachment.json", %{attachment: object})
-
-      assert attachment.type == "image"
-      assert attachment.pleroma.mime_type == "application/octet-stream"
-    end
   end
 
   test "put the url advertised in the Activity in to the url attribute" do
diff --git a/test/pleroma/web/media_proxy/media_proxy_controller_test.exs b/test/pleroma/web/media_proxy/media_proxy_controller_test.exs
index 800159c21..f7e52483c 100644
--- a/test/pleroma/web/media_proxy/media_proxy_controller_test.exs
+++ b/test/pleroma/web/media_proxy/media_proxy_controller_test.exs
@@ -71,10 +71,7 @@ defmodule Pleroma.Web.MediaProxy.MediaProxyControllerTest do
 
     test "it performs ReverseProxy.call with valid signature", %{conn: conn, url: url} do
       with_mock Pleroma.ReverseProxy,
-        call: fn _conn, _url, opts ->
-          assert opts[:sniff_content_type]
-          %Conn{status: :success}
-        end do
+        call: fn _conn, _url, _opts -> %Conn{status: :success} end do
         assert %Conn{status: :success} = get(conn, url)
       end
     end