diff --git a/gallery_dl/extractor/aryion.py b/gallery_dl/extractor/aryion.py
index 686adb8e..c8e5ccbb 100644
--- a/gallery_dl/extractor/aryion.py
+++ b/gallery_dl/extractor/aryion.py
@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 
-# Copyright 2020-2025 Mike Fährmann
+# Copyright 2020-2026 Mike Fährmann
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License version 2 as
@@ -156,11 +156,11 @@ class AryionExtractor(Extractor):
             headers = response.headers
 
             # folder
-            if headers["content-type"] in (
+            if headers["content-type"] in {
                 "application/x-folder",
                 "application/x-comic-folder",
                 "application/x-comic-folder-nomerge",
-            ):
+            }:
                 return False
 
             # get filename from 'Content-Disposition' header
diff --git a/gallery_dl/extractor/common.py b/gallery_dl/extractor/common.py
index 5879f425..794c5aae 100644
--- a/gallery_dl/extractor/common.py
+++ b/gallery_dl/extractor/common.py
@@ -784,7 +784,7 @@ class Extractor():
             with open(path + ".txt", 'wb') as fp:
                 util.dump_response(
                     response, fp,
-                    headers=(self._write_pages in ("all", "ALL")),
+                    headers=(self._write_pages in {"all", "ALL"}),
                     hide_auth=(self._write_pages != "ALL")
                 )
             self.log.info("Writing '%s' response to '%s'",
diff --git a/gallery_dl/extractor/discord.py b/gallery_dl/extractor/discord.py
index 6b91ae01..ef2943ec 100644
--- a/gallery_dl/extractor/discord.py
+++ b/gallery_dl/extractor/discord.py
@@ -60,7 +60,7 @@ class DiscordExtractor(Extractor):
 
     def extract_message(self, message):
         # https://discord.com/developers/docs/resources/message#message-object-message-types
-        if message["type"] in (0, 19, 21):
+        if message["type"] in {0, 19, 21}:
             message_metadata = {}
             message_metadata.update(self.server_metadata)
             message_metadata.update(
@@ -92,7 +92,7 @@ class DiscordExtractor(Extractor):
             message_snapshots = [message]
             message_snapshots.extend(
                 msg["message"] for msg in message.get("message_snapshots", [])
-                if msg["message"]["type"] in (0, 19, 21)
+                if msg["message"]["type"] in {0, 19, 21}
             )
 
             for snapshot in message_snapshots:
@@ -153,15 +153,15 @@ class DiscordExtractor(Extractor):
             )
 
             # https://discord.com/developers/docs/resources/channel#channel-object-channel-types
-            if channel_type in (0, 5):
+            if channel_type in {0, 5}:
                 yield from self.extract_channel_text(channel_id)
                 if self.enabled_threads:
                     yield from self.extract_channel_threads(channel_id)
-            elif channel_type in (1, 3, 10, 11, 12):
+            elif channel_type in {1, 3, 10, 11, 12}:
                 yield from self.extract_channel_text(channel_id)
-            elif channel_type in (15, 16):
+            elif channel_type in {15, 16}:
                 yield from self.extract_channel_threads(channel_id)
-            elif channel_type in (4,):
+            elif channel_type == 4:
                 for channel in self.server_channels_metadata.copy().values():
                     if channel["parent_id"] == channel_id:
                         yield from self.extract_channel(
@@ -192,7 +192,7 @@ class DiscordExtractor(Extractor):
                 "parent_type": parent_metadata["channel_type"]
             })
 
-        if channel_metadata["channel_type"] in (1, 3):
+        if channel_metadata["channel_type"] in {1, 3}:
             channel_metadata.update({
                 "channel": "DMs",
                 "recipients": (
@@ -355,7 +355,7 @@ class DiscordServerExtractor(DiscordExtractor):
         self.build_server_and_channels(server_id)
 
         for channel in self.server_channels_metadata.copy().values():
-            if channel["channel_type"] in (0, 5, 15, 16):
+            if channel["channel_type"] in {0, 5, 15, 16}:
                 yield from self.extract_channel(
                     channel["channel_id"], safe=True)
 
diff --git a/gallery_dl/extractor/fapello.py b/gallery_dl/extractor/fapello.py
index 2bd7a1fc..4cd97a69 100644
--- a/gallery_dl/extractor/fapello.py
+++ b/gallery_dl/extractor/fapello.py
@@ -97,7 +97,7 @@ class FapelloPathExtractor(Extractor):
 
     def items(self):
         num = 1
-        if self.path in ("top-likes", "top-followers"):
+        if self.path in {"top-likes", "top-followers"}:
             data = {"_extractor": FapelloModelExtractor}
         else:
             data = {"_extractor": FapelloPostExtractor}
diff --git a/gallery_dl/extractor/gelbooru.py b/gallery_dl/extractor/gelbooru.py
index ffba38ab..30e32f8c 100644
--- a/gallery_dl/extractor/gelbooru.py
+++ b/gallery_dl/extractor/gelbooru.py
@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 
-# Copyright 2014-2025 Mike Fährmann
+# Copyright 2014-2026 Mike Fährmann
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License version 2 as
@@ -217,7 +217,7 @@ class GelbooruFavoriteExtractor(GelbooruBase,
                            "a" if order > 0 else "de")
 
         order_favs = self.config("order-posts")
-        if order_favs and order_favs[0] in ("r", "a"):
+        if order_favs and order_favs[0] in {"r", "a"}:
             self.log.debug("Returning them in reverse")
             order = -order
 
diff --git a/gallery_dl/extractor/hotleak.py b/gallery_dl/extractor/hotleak.py
index 9c849a8c..0cc6cd62 100644
--- a/gallery_dl/extractor/hotleak.py
+++ b/gallery_dl/extractor/hotleak.py
@@ -160,9 +160,9 @@ class HotleakCategoryExtractor(HotleakExtractor):
     def items(self):
         url = f"{self.root}/{self._category}"
 
-        if self._category in ("hot", "creators"):
+        if self._category in {"hot", "creators"}:
             data = {"_extractor": HotleakCreatorExtractor}
-        elif self._category in ("videos", "photos"):
+        elif self._category in {"videos", "photos"}:
             data = {"_extractor": HotleakPostExtractor}
 
         for item in self._pagination(url, self.params):
diff --git a/gallery_dl/extractor/instagram.py b/gallery_dl/extractor/instagram.py
index fa0b59b6..ce32587b 100644
--- a/gallery_dl/extractor/instagram.py
+++ b/gallery_dl/extractor/instagram.py
@@ -54,7 +54,7 @@ class InstagramExtractor(Extractor):
         self._warn_video = True if self.config("warn-videos", True) else False
         self._warn_image = (
             9 if not (wi := self.config("warn-images", True)) else
-            1 if wi in ("all", "both") else
+            1 if wi in {"all", "both"} else
             0)
 
     def items(self):
@@ -70,7 +70,7 @@ class InstagramExtractor(Extractor):
         max_posts = self.config("max-posts")
 
         order = self.config("order-files")
-        reverse = order[0] in ("r", "d") if order else False
+        reverse = order[0] in {"r", "d"} if order else False
 
         posts = self.posts()
         if max_posts:
@@ -831,9 +831,9 @@ class InstagramRestAPI():
         reel_ids = [hl["id"] for hl in self.highlights_tray(user_id)]
 
         if order := self.extractor.config("order-posts"):
-            if order in ("desc", "reverse"):
+            if order in {"desc", "reverse"}:
                 reel_ids.reverse()
-            elif order in ("id", "id_asc"):
+            elif order in {"id", "id_asc"}:
                 reel_ids.sort(key=lambda r: int(r[10:]))
             elif order == "id_desc":
                 reel_ids.sort(key=lambda r: int(r[10:]), reverse=True)
diff --git a/gallery_dl/extractor/kemono.py b/gallery_dl/extractor/kemono.py
index 8387350f..85bb169e 100644
--- a/gallery_dl/extractor/kemono.py
+++ b/gallery_dl/extractor/kemono.py
@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 
-# Copyright 2021-2025 Mike Fährmann
+# Copyright 2021-2026 Mike Fährmann
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License version 2 as
@@ -42,7 +42,7 @@ class KemonoExtractor(Extractor):
         if self.revisions:
             self.revisions_unique = (self.revisions == "unique")
         order = self.config("order-revisions")
-        self.revisions_reverse = order[0] in ("r", "a") if order else False
+        self.revisions_reverse = order[0] in {"r", "a"} if order else False
 
         self._find_inline = text.re(
             r'src="(?:https?://(?:kemono\.cr|coomer\.st))?(/inline/[^"]+'
@@ -352,7 +352,7 @@ class KemonoUserExtractor(KemonoExtractor):
         _, _, service, creator_id, query = self.groups
         params = text.parse_query(query)
 
-        if self.config("endpoint") in ("posts+", "legacy+"):
+        if self.config("endpoint") in {"posts+", "legacy+"}:
             endpoint = self.api.creator_posts_expand
         else:
             endpoint = self.api.creator_posts
@@ -439,7 +439,7 @@ class KemonoDiscordExtractor(KemonoExtractor):
         archives = True if self.config("archives") else False
         exts_archive = util.EXTS_ARCHIVE
 
-        if (order := self.config("order-posts")) and order[0] in ("r", "d"):
+        if (order := self.config("order-posts")) and order[0] in {"r", "d"}:
             posts = self.api.discord_channel(channel_id, channel["post_count"])
         else:
             posts = self.api.discord_channel(channel_id)
diff --git a/gallery_dl/extractor/misskey.py b/gallery_dl/extractor/misskey.py
index f37bcada..f9459dab 100644
--- a/gallery_dl/extractor/misskey.py
+++ b/gallery_dl/extractor/misskey.py
@@ -255,7 +255,7 @@ class MisskeyAPI():
 
         date_min, date_max = extr._get_date_min_max()
         if (order := extr.config("order-posts")) and \
-                order[0] in ("a", "r"):
+                order[0] in {"a", "r"}:
             key = "sinceId"
             data["sinceDate"] = 1 if date_min is None else date_min * 1000
             date_stop = None if date_max is None else date_max
diff --git a/gallery_dl/extractor/oauth.py b/gallery_dl/extractor/oauth.py
index a0e3c9f9..38bb5eeb 100644
--- a/gallery_dl/extractor/oauth.py
+++ b/gallery_dl/extractor/oauth.py
@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 
-# Copyright 2017-2025 Mike Fährmann
+# Copyright 2017-2026 Mike Fährmann
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License version 2 as
@@ -454,7 +454,7 @@ class OAuthPixiv(OAuthBase):
 
         if "error" in data:
             stdout_write(f"\n{data}\n")
-            if data["error"] in ("invalid_request", "invalid_grant"):
+            if data["error"] in {"invalid_request", "invalid_grant"}:
                 stdout_write("'code' expired, try again\n\n")
             return
 
diff --git a/gallery_dl/extractor/pixiv.py b/gallery_dl/extractor/pixiv.py
index 8463d9b8..0a4f6b34 100644
--- a/gallery_dl/extractor/pixiv.py
+++ b/gallery_dl/extractor/pixiv.py
@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 
-# Copyright 2014-2025 Mike Fährmann
+# Copyright 2014-2026 Mike Fährmann
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License version 2 as
@@ -131,11 +131,11 @@ class PixivExtractor(Extractor):
             self.log.debug("%s: %s", work_id, url)
 
             limit_type = url.rpartition("/")[2]
-            if limit_type in (
+            if limit_type in {
                 "limit_",  # for '_extend_sanity()' inserts
                 "limit_unviewable_360.png",
                 "limit_sanity_level_360.png",
-            ):
+            }:
                 work["_ajax"] = True
                 self.log.warning("%s: 'limit_sanity_level' warning", work_id)
                 if self.sanity_workaround:
diff --git a/gallery_dl/extractor/twitter.py b/gallery_dl/extractor/twitter.py
index 30931a29..dc5cf11b 100644
--- a/gallery_dl/extractor/twitter.py
+++ b/gallery_dl/extractor/twitter.py
@@ -299,7 +299,7 @@ class TwitterExtractor(Extractor):
                 if domain in cbl or name + ":" + domain in cbl:
                     return
 
-        if name in ("summary", "summary_large_image"):
+        if name in {"summary", "summary_large_image"}:
             for prefix in ("photo_image_full_size_",
                            "summary_photo_image_",
                            "thumbnail_image_"):
@@ -1080,7 +1080,7 @@ class TwitterTweetExtractor(TwitterExtractor):
             return self._tweets_conversation(self.tweet_id)
 
         endpoint = self.config("tweet-endpoint")
-        if endpoint == "detail" or endpoint in (None, "auto") and \
+        if endpoint == "detail" or endpoint in {None, "auto"} and \
                 self.api.headers["x-twitter-auth-type"]:
             return self._tweets_detail(self.tweet_id)
 
@@ -1402,7 +1402,7 @@ class TwitterAPI():
 
         if tweet.get("__typename") == "TweetUnavailable":
             reason = tweet.get("reason")
-            if reason in ("NsfwViewerHasNoStatedAge", "NsfwLoggedOut"):
+            if reason in {"NsfwViewerHasNoStatedAge", "NsfwLoggedOut"}:
                 raise exception.AuthRequired(message="NSFW Tweet")
             if reason == "Protected":
                 raise exception.AuthRequired(message="Protected Tweet")
@@ -1545,7 +1545,7 @@ class TwitterAPI():
         }
 
         pgn = cfg("search-pagination")
-        if pgn in ("max_id", "maxid", "id"):
+        if pgn in {"max_id", "maxid", "id"}:
             update_variables = self._update_variables_search_maxid
         elif pgn in {"until", "date", "datetime", "dt"}:
             update_variables = self._update_variables_search_date
@@ -1856,7 +1856,7 @@ class TwitterAPI():
 
             if response.status_code < 400:
                 return data
-            elif response.status_code in (403, 404) and \
+            elif response.status_code in {403, 404} and \
                     not self.headers["x-twitter-auth-type"]:
                 raise exception.AuthRequired(
                     "authenticated cookies", "timeline")
diff --git a/gallery_dl/extractor/utils/deviantart_tiptap.py b/gallery_dl/extractor/utils/deviantart_tiptap.py
index 36dfc6af..893310c2 100644
--- a/gallery_dl/extractor/utils/deviantart_tiptap.py
+++ b/gallery_dl/extractor/utils/deviantart_tiptap.py
@@ -66,7 +66,7 @@ def process_content(html, content):
         html.append(level)
         html.append(">")
 
-    elif type in ("listItem", "bulletList", "orderedList", "blockquote"):
+    elif type in {"listItem", "bulletList", "orderedList", "blockquote"}:
         c = type[1]
         tag = (
             "li" if c == "i" else
diff --git a/gallery_dl/extractor/wikimedia.py b/gallery_dl/extractor/wikimedia.py
index 97e6f2bd..1be211c3 100644
--- a/gallery_dl/extractor/wikimedia.py
+++ b/gallery_dl/extractor/wikimedia.py
@@ -30,7 +30,7 @@ class WikimediaExtractor(BaseExtractor):
             labels = self.root.split(".")
             self.lang = labels[-3][-2:]
             self.category = labels[-2]
-        elif self.category in ("fandom", "wikigg"):
+        elif self.category in {"fandom", "wikigg"}:
             self.lang = "en"
             self.format = "original"
             self.basesubcategory = self.category
diff --git a/gallery_dl/extractor/xenforo.py b/gallery_dl/extractor/xenforo.py
index 81a5d19a..3dd73c42 100644
--- a/gallery_dl/extractor/xenforo.py
+++ b/gallery_dl/extractor/xenforo.py
@@ -126,7 +126,7 @@ class XenforoExtractor(BaseExtractor):
 
     def items_media(self, path, pnum, callback=None):
         if (order := self.config("order-posts")) and \
-                order[0] in ("d", "r"):
+                order[0] in {"d", "r"}:
             pages = self._pagination_reverse(path, pnum, callback)
             reverse = True
         else:
@@ -491,7 +491,7 @@ class XenforoThreadExtractor(XenforoExtractor):
         pnum = self.groups[-1]
 
         if (order := self.config("order-posts")) and \
-                order[0] not in ("d", "r"):
+                order[0] not in {"d", "r"}:
             params = "?order=reaction_score" if order[0] == "s" else ""
             pages = self._pagination(path, pnum, params=params)
             reverse = False
diff --git a/gallery_dl/extractor/ytdl.py b/gallery_dl/extractor/ytdl.py
index c1358967..ede7ae52 100644
--- a/gallery_dl/extractor/ytdl.py
+++ b/gallery_dl/extractor/ytdl.py
@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 
-# Copyright 2021-2025 Mike Fährmann
+# Copyright 2021-2026 Mike Fährmann
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License version 2 as
@@ -126,7 +126,7 @@ class YoutubeDLExtractor(Extractor):
             if not entry:
                 continue
 
-            if entry.get("_type") in ("url", "url_transparent"):
+            if entry.get("_type") in {"url", "url_transparent"}:
                 try:
                     entry = ytdl_instance.extract_info(
                         entry["url"], False,
diff --git a/gallery_dl/extractor/zerochan.py b/gallery_dl/extractor/zerochan.py
index 13e2f167..75060ea7 100644
--- a/gallery_dl/extractor/zerochan.py
+++ b/gallery_dl/extractor/zerochan.py
@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 
-# Copyright 2022-2025 Mike Fährmann
+# Copyright 2022-2026 Mike Fährmann
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License version 2 as
@@ -294,7 +294,7 @@ class ZerochanImageExtractor(ZerochanExtractor):
         try:
             post = self._parse_entry_html(image_id)
         except exception.HttpError as exc:
-            if exc.status in (404, 410):
+            if exc.status in {404, 410}:
                 if msg := text.extr(exc.response.text, "<h2>", "<"):
                     self.log.warning(f"'{msg}'")
                 return ()