diff --git a/web/src/click_handlers.ts b/web/src/click_handlers.ts
index 8c5b99e169..2751e5e718 100644
--- a/web/src/click_handlers.ts
+++ b/web/src/click_handlers.ts
@@ -683,7 +683,7 @@ export function initialize(): void {
             const $elem = $(this);
             const user_ids_string = $elem.attr("data-user-ids-string");
             // Don't show tooltip for group direct messages.
-            if (!user_ids_string || user_ids_string.split(",").length !== 1) {
+            if (user_ids_string?.split(",").length !== 1) {
                 return;
             }
             const title_data = recent_view_ui.get_pm_tooltip_data(user_ids_string);
diff --git a/web/src/compose_paste.ts b/web/src/compose_paste.ts
index f37bcc6ce9..8b7168c530 100644
--- a/web/src/compose_paste.ts
+++ b/web/src/compose_paste.ts
@@ -127,7 +127,7 @@ export function is_white_space_pre(paste_html: string): boolean {
 
 function is_from_excel(html_fragment: HTMLBodyElement): boolean {
     const html_tag = html_fragment.parentElement;
-    if (!html_tag || html_tag.nodeName !== "HTML") {
+    if (html_tag?.nodeName !== "HTML") {
         return false;
     }
 
@@ -166,7 +166,7 @@ function is_from_excel(html_fragment: HTMLBodyElement): boolean {
 // something like LibreOffice Writer.
 function is_from_libreoffice_calc(body_tag: HTMLBodyElement): boolean {
     const html_tag = body_tag.parentElement;
-    if (!html_tag || html_tag.nodeName !== "HTML") {
+    if (html_tag?.nodeName !== "HTML") {
         return false;
     }
 
diff --git a/web/src/composebox_typeahead.ts b/web/src/composebox_typeahead.ts
index 96cc06d1a8..b279acbb6c 100644
--- a/web/src/composebox_typeahead.ts
+++ b/web/src/composebox_typeahead.ts
@@ -1253,8 +1253,7 @@ export function content_typeahead_selected(
             const sub = stream_data.get_sub_by_name(item.name);
             const is_empty_topic_only_channel =
                 sub && stream_data.is_empty_topic_only_channel(sub.stream_id);
-            const is_greater_than_key_pressed =
-                event && event.type === "keydown" && event.key === ">";
+            const is_greater_than_key_pressed = event?.type === "keydown" && event.key === ">";
 
             // For empty topic only channel, skip showing topic typeahead and
             // insert direct channel link.
diff --git a/web/src/hotkey.ts b/web/src/hotkey.ts
index 1f03cc0927..9f7f28e2f8 100644
--- a/web/src/hotkey.ts
+++ b/web/src/hotkey.ts
@@ -1199,7 +1199,7 @@ function process_hotkey(e: JQuery.KeyDownEvent, hotkey: Hotkey): boolean {
         case "toggle_topic_visibility_policy":
             if (recent_view_ui.is_in_focus()) {
                 const recent_msg = recent_view_ui.get_focused_row_message();
-                if (recent_msg !== undefined && recent_msg.type === "stream") {
+                if (recent_msg?.type === "stream") {
                     user_topics_ui.toggle_topic_visibility_policy(recent_msg);
                     return true;
                 }
@@ -1217,13 +1217,13 @@ function process_hotkey(e: JQuery.KeyDownEvent, hotkey: Hotkey): boolean {
         case "list_of_channel_topics":
             if (recent_view_ui.is_in_focus()) {
                 const msg = recent_view_ui.get_focused_row_message();
-                if (msg !== undefined && msg.type === "stream") {
+                if (msg?.type === "stream") {
                     list_of_channel_topics_channel_id = msg.stream_id;
                 }
             }
             if (inbox_ui.is_in_focus()) {
                 const msg = inbox_ui.get_focused_row_message();
-                if (msg !== undefined && msg.msg_type === "stream") {
+                if (msg?.msg_type === "stream") {
                     list_of_channel_topics_channel_id = msg.stream_id;
                 }
             }
diff --git a/web/src/integration_url_modal.ts b/web/src/integration_url_modal.ts
index 3cacc2b334..633b5013b4 100644
--- a/web/src/integration_url_modal.ts
+++ b/web/src/integration_url_modal.ts
@@ -106,8 +106,7 @@ export function show_generate_integration_url_modal(api_key: string): void {
 
             if (
                 !$("#integration-url-all-branches").prop("checked") &&
-                branch_pill_widget !== undefined &&
-                branch_pill_widget.items().length === 0
+                branch_pill_widget?.items().length === 0
             ) {
                 branch_pill_widget.appendValue("main");
             }
diff --git a/web/src/message_view.ts b/web/src/message_view.ts
index 1a322ca099..164783632a 100644
--- a/web/src/message_view.ts
+++ b/web/src/message_view.ts
@@ -90,7 +90,7 @@ export function reset_ui_state(opts: {trigger?: string}): void {
     // Most users aren't going to send a bunch of a out-of-narrow messages
     // and expect to visit a list of narrows, so let's get these out of the way.
     let skip_automatic_new_visibility_policy_banner = false;
-    if (opts && opts.trigger === "outside_current_view") {
+    if (opts?.trigger === "outside_current_view") {
         skip_automatic_new_visibility_policy_banner = true;
     }
     compose_banner.clear_message_sent_banners(true, skip_automatic_new_visibility_policy_banner);
diff --git a/web/src/rendered_markdown.ts b/web/src/rendered_markdown.ts
index e0932f2f16..0932b0ce34 100644
--- a/web/src/rendered_markdown.ts
+++ b/web/src/rendered_markdown.ts
@@ -322,7 +322,7 @@ export const update_elements = ($content: JQuery): void => {
         const $codehilite = $(this);
         const $pre = $codehilite.find("pre");
         const fenced_code_lang = $codehilite.attr("data-code-language");
-        let playground_info;
+        let playground_info: realm_playground.RealmPlayground[] | undefined;
         if (fenced_code_lang !== undefined) {
             playground_info = realm_playground.get_playground_info_for_languages(fenced_code_lang);
         }
@@ -339,11 +339,7 @@ export const update_elements = ($content: JQuery): void => {
             // popover listing the options.
             let title = $t({defaultMessage: "View in playground"});
             const $view_in_playground_button = $buttonContainer.find(".code_external_link");
-            if (
-                playground_info &&
-                playground_info.length === 1 &&
-                playground_info[0] !== undefined
-            ) {
+            if (playground_info?.length === 1 && playground_info[0] !== undefined) {
                 title = $t(
                     {defaultMessage: "View in {playground_name}"},
                     {playground_name: playground_info[0].name},
diff --git a/web/src/spoilers.ts b/web/src/spoilers.ts
index d7ed450c62..cd2ef15477 100644
--- a/web/src/spoilers.ts
+++ b/web/src/spoilers.ts
@@ -66,7 +66,7 @@ export function initialize(): void {
 
         // Allow selecting text inside a spoiler header.
         const selection = document.getSelection();
-        if (selection && selection.type === "Range") {
+        if (selection?.type === "Range") {
             return;
         }
 
diff --git a/web/src/unread.ts b/web/src/unread.ts
index 41628561ab..723c9641fc 100644
--- a/web/src/unread.ts
+++ b/web/src/unread.ts
@@ -597,7 +597,7 @@ class UnreadTopicCounter {
             // topic in this stream containing a given unread message
             // ID. If it's not in this stream, we'll get undefined.
             const stream_topic = this.reverse_lookup.get(message_id);
-            if (stream_topic !== undefined && stream_topic.stream_id === stream_id) {
+            if (stream_topic?.stream_id === stream_id) {
                 // Important: We lower-case topics here before adding them
                 // to this set, to support case-insensitive checks.
                 result.add(stream_topic.topic.toLowerCase());