diff --git a/scripts/lib/unpack-zulip b/scripts/lib/unpack-zulip
index b9d458817a..1102e3fd1b 100755
--- a/scripts/lib/unpack-zulip
+++ b/scripts/lib/unpack-zulip
@@ -36,7 +36,7 @@ current_version = version.ZULIP_VERSION
 if is_invalid_upgrade(current_version, new_version):
     print(
         FAIL + "Your current version is very old. Please first upgrade to version "
-        "1.4.3 and then upgrade to {}.".format(new_version) + ENDC
+        f"1.4.3 and then upgrade to {new_version}." + ENDC
     )
     shutil.rmtree(extract_path)
     sys.exit(1)
diff --git a/tools/droplets/add_mentor.py b/tools/droplets/add_mentor.py
index e11986e01e..6f113ec79a 100644
--- a/tools/droplets/add_mentor.py
+++ b/tools/droplets/add_mentor.py
@@ -52,7 +52,7 @@ if __name__ == "__main__":
 
     if args.remove:
         remove_re = re.compile(
-            "#<{0}>{{{{.+}}}}<{0}>(\n)?".format(args.username), re.DOTALL | re.MULTILINE
+            rf"#<{args.username}>{{{{.+}}}}<{args.username}>(\n)?", re.DOTALL | re.MULTILINE
         )
 
         with open(authorized_keys, "r+") as f:
diff --git a/tools/droplets/create.py b/tools/droplets/create.py
index c9e0427ca4..64aa03d347 100644
--- a/tools/droplets/create.py
+++ b/tools/droplets/create.py
@@ -97,8 +97,8 @@ def assert_droplet_does_not_exist(my_token: str, droplet_name: str, recreate: bo
         if droplet.name.lower() == droplet_name:
             if not recreate:
                 print(
-                    "Droplet {} already exists. Pass --recreate if you "
-                    "need to recreate the droplet.".format(droplet_name)
+                    f"Droplet {droplet_name} already exists. Pass --recreate if you "
+                    "need to recreate the droplet."
                 )
                 sys.exit(1)
             else:
@@ -251,8 +251,8 @@ def create_dns_record(my_token: str, record_name: str, ipv4: str, ipv6: str) ->
 
 def print_dev_droplet_instructions(username: str, droplet_domain_name: str) -> None:
     print(
-        """
-COMPLETE! Droplet for GitHub user {0} is available at {1}.
+        f"""
+COMPLETE! Droplet for GitHub user {username} is available at {droplet_domain_name}.
 
 Instructions for use are below. (copy and paste to the user)
 
@@ -260,16 +260,14 @@ Instructions for use are below. (copy and paste to the user)
 Your remote Zulip dev server has been created!
 
 - Connect to your server by running
-  `ssh zulipdev@{1}` on the command line
+  `ssh zulipdev@{droplet_domain_name}` on the command line
   (Terminal for macOS and Linux, Bash for Git on Windows).
 - There is no password; your account is configured to use your SSH keys.
 - Once you log in, you should see `(zulip-py3-venv) ~$`.
 - To start the dev server, `cd zulip` and then run `./tools/run-dev`.
 - While the dev server is running, you can see the Zulip server in your browser at
-  http://{1}:9991.
-""".format(
-            username, droplet_domain_name
-        )
+  http://{droplet_domain_name}:9991.
+"""
     )
 
     print(
diff --git a/tools/generate-integration-docs-screenshot b/tools/generate-integration-docs-screenshot
index 9acc395fd3..52e761fd7e 100755
--- a/tools/generate-integration-docs-screenshot
+++ b/tools/generate-integration-docs-screenshot
@@ -130,8 +130,8 @@ def custom_headers(headers_json: str) -> Dict[str, str]:
         return orjson.loads(headers_json)
     except orjson.JSONDecodeError as ve:
         raise argparse.ArgumentTypeError(
-            "Encountered an error while attempting to parse custom headers: {}\n"
-            "Note: all strings must be enclosed within \"\" instead of ''".format(ve)
+            f"Encountered an error while attempting to parse custom headers: {ve}\n"
+            "Note: all strings must be enclosed within \"\" instead of ''"
         )
 
 
@@ -156,10 +156,8 @@ def send_bot_mock_message(
         client.send_message(request)
     except KeyError:
         print(
-            "{} contains invalid configuration. "
-            'Fields "subject" and "body" are required for non-webhook integrations.'.format(
-                fixture_path
-            )
+            f"{fixture_path} contains invalid configuration. "
+            'Fields "subject" and "body" are required for non-webhook integrations.'
         )
         sys.exit(1)
 
diff --git a/zerver/lib/bot_config.py b/zerver/lib/bot_config.py
index d1097e05e6..aa3a0e9708 100644
--- a/zerver/lib/bot_config.py
+++ b/zerver/lib/bot_config.py
@@ -55,10 +55,8 @@ def set_bot_config(bot_profile: UserProfile, key: str, value: str) -> None:
     new_config_size = old_config_size + (new_entry_size - old_entry_size)
     if new_config_size > config_size_limit:
         raise ConfigError(
-            "Cannot store configuration. Request would require {} characters. "
-            "The current configuration size limit is {} characters.".format(
-                new_config_size, config_size_limit
-            )
+            f"Cannot store configuration. Request would require {new_config_size} characters. "
+            f"The current configuration size limit is {config_size_limit} characters."
         )
     obj, created = BotConfigData.objects.get_or_create(
         bot_profile=bot_profile, key=key, defaults={"value": value}
diff --git a/zerver/lib/zcommand.py b/zerver/lib/zcommand.py
index e29335499b..a92b40a301 100644
--- a/zerver/lib/zcommand.py
+++ b/zerver/lib/zcommand.py
@@ -11,13 +11,7 @@ def process_zcommands(content: str, user_profile: UserProfile) -> Dict[str, Any]
     def change_mode_setting(
         setting_name: str, switch_command: str, setting: str, setting_value: int
     ) -> str:
-        msg = (
-            "Changed to {setting_name}! To revert "
-            "{setting_name}, type `/{switch_command}`.".format(
-                setting_name=setting_name,
-                switch_command=switch_command,
-            )
-        )
+        msg = f"Changed to {setting_name}! To revert {setting_name}, type `/{switch_command}`."
         do_change_user_setting(
             user_profile=user_profile,
             setting_name=setting,
diff --git a/zerver/management/commands/send_webhook_fixture_message.py b/zerver/management/commands/send_webhook_fixture_message.py
index 609b648373..5f8524dce7 100644
--- a/zerver/management/commands/send_webhook_fixture_message.py
+++ b/zerver/management/commands/send_webhook_fixture_message.py
@@ -56,8 +56,8 @@ approach shown above.
             custom_headers_dict = orjson.loads(custom_headers)
         except orjson.JSONDecodeError as ve:
             raise CommandError(
-                "Encountered an error while attempting to parse custom headers: {}\n"
-                "Note: all strings must be enclosed within \"\" instead of ''".format(ve)
+                f"Encountered an error while attempting to parse custom headers: {ve}\n"
+                "Note: all strings must be enclosed within \"\" instead of ''"
             )
         return standardize_headers(custom_headers_dict)
 
diff --git a/zerver/tests/test_auth_backends.py b/zerver/tests/test_auth_backends.py
index c6c37a2d5f..73a4298f11 100644
--- a/zerver/tests/test_auth_backends.py
+++ b/zerver/tests/test_auth_backends.py
@@ -1719,9 +1719,9 @@ class SocialAuthBase(DesktopFlowTestingLib, ZulipTestCase, ABC):
         self.assertEqual(result.status_code, 200)
         self.assert_in_response('action="/register/"', result)
         self.assert_in_response(
-            "Your email address, {}, is not "
+            f"Your email address, {email}, is not "
             "in one of the domains that are allowed to register "
-            "for accounts in this organization.".format(email),
+            "for accounts in this organization.",
             result,
         )
 
diff --git a/zerver/tests/test_markdown.py b/zerver/tests/test_markdown.py
index 1459e37876..1d06850df3 100644
--- a/zerver/tests/test_markdown.py
+++ b/zerver/tests/test_markdown.py
@@ -2543,12 +2543,12 @@ class MarkdownTest(ZulipTestCase):
             render_markdown(msg, content).rendered_content,
             "<p>Look to "
             '<a class="stream" '
-            'data-stream-id="{denmark.id}" '
-            'href="/#narrow/stream/{denmark.id}-Denmark">#{denmark.name}</a> and '
+            f'data-stream-id="{denmark.id}" '
+            f'href="/#narrow/stream/{denmark.id}-Denmark">#{denmark.name}</a> and '
             '<a class="stream" '
-            'data-stream-id="{scotland.id}" '
-            'href="/#narrow/stream/{scotland.id}-Scotland">#{scotland.name}</a>, '
-            "there something</p>".format(denmark=denmark, scotland=scotland),
+            f'data-stream-id="{scotland.id}" '
+            f'href="/#narrow/stream/{scotland.id}-Scotland">#{scotland.name}</a>, '
+            "there something</p>",
         )
 
     def test_stream_case_sensitivity(self) -> None:
@@ -2622,14 +2622,14 @@ class MarkdownTest(ZulipTestCase):
         self.assertEqual(
             render_markdown(msg, content).rendered_content,
             "<p>This has two links: "
-            '<a class="stream-topic" data-stream-id="{denmark.id}" '
-            'href="/#narrow/stream/{denmark.id}-{denmark.name}/topic/some.20topic">'
-            "#{denmark.name} &gt; some topic</a>"
+            f'<a class="stream-topic" data-stream-id="{denmark.id}" '
+            f'href="/#narrow/stream/{denmark.id}-{denmark.name}/topic/some.20topic">'
+            f"#{denmark.name} &gt; some topic</a>"
             " and "
-            '<a class="stream-topic" data-stream-id="{scotland.id}" '
-            'href="/#narrow/stream/{scotland.id}-{scotland.name}/topic/other.20topic">'
-            "#{scotland.name} &gt; other topic</a>"
-            ".</p>".format(denmark=denmark, scotland=scotland),
+            f'<a class="stream-topic" data-stream-id="{scotland.id}" '
+            f'href="/#narrow/stream/{scotland.id}-{scotland.name}/topic/other.20topic">'
+            f"#{scotland.name} &gt; other topic</a>"
+            ".</p>",
         )
 
     def test_possible_stream_names(self) -> None:
@@ -2652,10 +2652,7 @@ class MarkdownTest(ZulipTestCase):
         href = f"/#narrow/stream/{uni.id}-{quoted_name}"
         self.assertEqual(
             render_markdown(msg, content).rendered_content,
-            '<p><a class="stream" data-stream-id="{s.id}" href="{href}">#{s.name}</a></p>'.format(
-                s=uni,
-                href=href,
-            ),
+            f'<p><a class="stream" data-stream-id="{uni.id}" href="{href}">#{uni.name}</a></p>',
         )
 
     def test_stream_atomic_string(self) -> None:
diff --git a/zerver/tests/test_message_send.py b/zerver/tests/test_message_send.py
index d4ffd76c78..ac2d92c3e5 100644
--- a/zerver/tests/test_message_send.py
+++ b/zerver/tests/test_message_send.py
@@ -1501,8 +1501,7 @@ class StreamMessagesTest(ZulipTestCase):
         message = most_recent_message(receiving_user_profile)
         self.assertEqual(
             repr(message),
-            "<Message: Denmark / my topic / "
-            "<UserProfile: {} {!r}>>".format(sender.email, sender.realm),
+            f"<Message: Denmark / my topic / <UserProfile: {sender.email} {sender.realm!r}>>",
         )
 
     def test_message_mentions(self) -> None:
diff --git a/zerver/tests/test_retention.py b/zerver/tests/test_retention.py
index c2ebea6ddd..51fbd04894 100644
--- a/zerver/tests/test_retention.py
+++ b/zerver/tests/test_retention.py
@@ -673,20 +673,16 @@ class MoveMessageToArchiveGeneral(MoveMessageToArchiveBase):
         self._create_attachments()
         realm_id = get_realm("zulip").id
         host = get_realm("zulip").host
-        body1 = """Some files here ...[zulip.txt](
-            http://{host}/user_uploads/{id}/31/4CBjtTLYZhk66pZrF8hnYGwc/zulip.txt)
-            http://{host}/user_uploads/{id}/31/4CBjtTLYZhk66pZrF8hnYGwc/temp_file.py ....
-            Some more.... http://{host}/user_uploads/{id}/31/4CBjtTLYZhk66pZrF8hnYGwc/abc.py
-        """.format(
-            id=realm_id, host=host
-        )
-        body2 = """Some files here
-            http://{host}/user_uploads/{id}/31/4CBjtTLYZhk66pZrF8hnYGwc/zulip.txt ...
-            http://{host}/user_uploads/{id}/31/4CBjtTLYZhk66pZrF8hnYGwc/hello.txt ....
-            http://{host}/user_uploads/{id}/31/4CBjtTLYZhk66pZrF8hnYGwc/new.py ....
-        """.format(
-            id=realm_id, host=host
-        )
+        body1 = f"""Some files here ...[zulip.txt](
+            http://{host}/user_uploads/{realm_id}/31/4CBjtTLYZhk66pZrF8hnYGwc/zulip.txt)
+            http://{host}/user_uploads/{realm_id}/31/4CBjtTLYZhk66pZrF8hnYGwc/temp_file.py ....
+            Some more.... http://{host}/user_uploads/{realm_id}/31/4CBjtTLYZhk66pZrF8hnYGwc/abc.py
+        """
+        body2 = f"""Some files here
+            http://{host}/user_uploads/{realm_id}/31/4CBjtTLYZhk66pZrF8hnYGwc/zulip.txt ...
+            http://{host}/user_uploads/{realm_id}/31/4CBjtTLYZhk66pZrF8hnYGwc/hello.txt ....
+            http://{host}/user_uploads/{realm_id}/31/4CBjtTLYZhk66pZrF8hnYGwc/new.py ....
+        """
 
         msg_ids = [
             self.send_personal_message(self.sender, self.recipient, body1),
diff --git a/zerver/tests/test_signup.py b/zerver/tests/test_signup.py
index 48ab3e0bd5..8b74f22888 100644
--- a/zerver/tests/test_signup.py
+++ b/zerver/tests/test_signup.py
@@ -342,7 +342,7 @@ class AddNewUserHistoryTest(ZulipTestCase):
             self.assertEqual(
                 repr(message),
                 "<Message: recip /  / "
-                "<UserProfile: {} {!r}>>".format(user_profile.email, user_profile.realm),
+                f"<UserProfile: {user_profile.email} {user_profile.realm!r}>>",
             )
 
             user_message = most_recent_usermessage(user_profile)
diff --git a/zerver/tests/test_upload.py b/zerver/tests/test_upload.py
index 29c51b8a7e..8083240d81 100644
--- a/zerver/tests/test_upload.py
+++ b/zerver/tests/test_upload.py
@@ -598,7 +598,7 @@ class FileUploadTest(UploadSerializeMixin, ZulipTestCase):
         self.subscribe(hamlet, "test")
         body = (
             f"[f1.txt](http://{host}/user_uploads/" + f1_path_id + ") "
-            "[f2.txt](http://{}/user_uploads/".format(host) + f2_path_id + ")"
+            f"[f2.txt](http://{host}/user_uploads/" + f2_path_id + ")"
         )
         msg_id = self.send_stream_message(hamlet, "test", body, "test")
 
@@ -608,7 +608,7 @@ class FileUploadTest(UploadSerializeMixin, ZulipTestCase):
 
         new_body = (
             f"[f3.txt](http://{host}/user_uploads/" + f3_path_id + ") "
-            "[f2.txt](http://{}/user_uploads/".format(host) + f2_path_id + ")"
+            f"[f2.txt](http://{host}/user_uploads/" + f2_path_id + ")"
         )
         result = self.client_patch(
             "/json/messages/" + str(msg_id),
diff --git a/zerver/webhooks/front/view.py b/zerver/webhooks/front/view.py
index 9384afc7de..ba74429fa5 100644
--- a/zerver/webhooks/front/view.py
+++ b/zerver/webhooks/front/view.py
@@ -41,20 +41,16 @@ def get_target_name(payload: WildValue) -> str:
 def get_inbound_message_body(payload: WildValue) -> str:
     link, outbox, inbox, subject = get_message_data(payload)
     return (
-        "[Inbound message]({link}) from **{outbox}** to **{inbox}**:\n"
-        "```quote\n*Subject*: {subject}\n```".format(
-            link=link, outbox=outbox, inbox=inbox, subject=subject
-        )
+        f"[Inbound message]({link}) from **{outbox}** to **{inbox}**:\n"
+        f"```quote\n*Subject*: {subject}\n```"
     )
 
 
 def get_outbound_message_body(payload: WildValue) -> str:
     link, outbox, inbox, subject = get_message_data(payload)
     return (
-        "[Outbound message]({link}) from **{inbox}** to **{outbox}**:\n"
-        "```quote\n*Subject*: {subject}\n```".format(
-            link=link, inbox=inbox, outbox=outbox, subject=subject
-        )
+        f"[Outbound message]({link}) from **{inbox}** to **{outbox}**:\n"
+        f"```quote\n*Subject*: {subject}\n```"
     )