diff --git a/packages/analysis_defaults/lib/analysis.yaml b/packages/analysis_defaults/lib/analysis.yaml
index 1124c9938b6..904b49148b4 100644
--- a/packages/analysis_defaults/lib/analysis.yaml
+++ b/packages/analysis_defaults/lib/analysis.yaml
@@ -8,10 +8,13 @@ analyzer:
 
 linter:
   rules:
+    - async_return_with_no_await
     - deprecated_member_use_from_same_package
     - discarded_futures
+    - empty_container_bodies
     - eol_at_end_of_file
     - implicit_reopen
+    - initialize_in_field_declaration
     - invalid_case_patterns
     - matching_super_parameters
     - missing_code_block_language_in_doc_comment
@@ -20,7 +23,15 @@ linter:
     - prefer_final_fields
     - prefer_final_in_for_each
     - prefer_final_locals
+    - prefer_if_elements_to_conditional_expressions
+    - simple_directive_paths
+    - simplify_variable_pattern
+    - specify_nonobvious_property_types
+    - switch_on_type
+    - unnecessary_async
     - unnecessary_breaks
     - unnecessary_null_aware_operator_on_extension_on_nullable
+    - unnecessary_primary_constructor_body
+    - unnecessary_unawaited
     - use_enums
     - use_truncating_division
diff --git a/packages/analysis_defaults/pubspec.yaml b/packages/analysis_defaults/pubspec.yaml
index c40a6861ba1..2abf344f95f 100644
--- a/packages/analysis_defaults/pubspec.yaml
+++ b/packages/analysis_defaults/pubspec.yaml
@@ -4,7 +4,7 @@ publish_to: none
 
 resolution: workspace
 environment:
-  sdk: ^3.12.0
+  sdk: ^3.13.0
 
 # NOTE: Code isn't allowed in this package.
 # Don't add dependencies besides the underlying lints package.
diff --git a/packages/site_shared/lib/components/blog/client/blog_categories.dart b/packages/site_shared/lib/components/blog/client/blog_categories.dart
index 1976a4561d5..2719bde8881 100644
--- a/packages/site_shared/lib/components/blog/client/blog_categories.dart
+++ b/packages/site_shared/lib/components/blog/client/blog_categories.dart
@@ -152,7 +152,7 @@ class _BlogCategoriesState extends State<BlogCategories> {
         [
           button(
             onClick: () => _selectCategory(null),
-            [const .text('All')],
+            const [.text('All')],
           ),
         ],
       ),
diff --git a/packages/site_shared/lib/components/blog/client/share_button.dart b/packages/site_shared/lib/components/blog/client/share_button.dart
index 0eefef47098..bc93b3c1d74 100644
--- a/packages/site_shared/lib/components/blog/client/share_button.dart
+++ b/packages/site_shared/lib/components/blog/client/share_button.dart
@@ -42,9 +42,9 @@ class ShareButton extends StatelessComponent {
                       to: false,
                     );
                   },
-                  [
-                    const MaterialIcon('content_copy'),
-                    const .text('Copy link'),
+                  const [
+                    MaterialIcon('content_copy'),
+                    .text('Copy link'),
                   ],
                 );
               },
@@ -58,8 +58,8 @@ class ShareButton extends StatelessComponent {
               href:
                   'https://twitter.com/intent/tweet?text=${Uri.encodeComponent(title)}&url=${Uri.encodeComponent(url)}',
               target: Target.blank,
-              [
-                const svg([
+              const [
+                svg([
                   Component.element(
                     tag: 'use',
                     attributes: {
@@ -67,7 +67,7 @@ class ShareButton extends StatelessComponent {
                     },
                   ),
                 ]),
-                const .text('Share on X'),
+                .text('Share on X'),
               ],
             ),
           ]),
@@ -76,8 +76,8 @@ class ShareButton extends StatelessComponent {
               href:
                   'https://bsky.app/intent/compose?text=${Uri.encodeComponent("$title $url")}',
               target: Target.blank,
-              [
-                const svg([
+              const [
+                svg([
                   Component.element(
                     tag: 'use',
                     attributes: {
@@ -85,7 +85,7 @@ class ShareButton extends StatelessComponent {
                     },
                   ),
                 ]),
-                const .text('Share on Bluesky'),
+                .text('Share on Bluesky'),
               ],
             ),
           ]),
@@ -94,8 +94,8 @@ class ShareButton extends StatelessComponent {
               href:
                   'https://www.linkedin.com/sharing/share-offsite/?url=${Uri.encodeComponent(url)}',
               target: Target.blank,
-              [
-                const svg([
+              const [
+                svg([
                   Component.element(
                     tag: 'use',
                     attributes: {
@@ -103,7 +103,7 @@ class ShareButton extends StatelessComponent {
                     },
                   ),
                 ]),
-                const .text('Share on LinkedIn'),
+                .text('Share on LinkedIn'),
               ],
             ),
           ]),
diff --git a/packages/site_shared/lib/components/common/button.dart b/packages/site_shared/lib/components/common/button.dart
index 2393c7f4706..9457ea1af56 100644
--- a/packages/site_shared/lib/components/common/button.dart
+++ b/packages/site_shared/lib/components/common/button.dart
@@ -61,7 +61,7 @@ class Button extends StatelessComponent {
     final children = <Component>[
       if (icon case final iconId?) MaterialIcon(iconId),
       if (content case final contentText?)
-        asRaw ? RawText(contentText) : .text(contentText),
+        if (asRaw) RawText(contentText) else .text(contentText),
       if (trailingIcon case final iconId?) MaterialIcon(iconId),
     ];
 
diff --git a/packages/site_shared/lib/components/common/chip.dart b/packages/site_shared/lib/components/common/chip.dart
index 080ec351b95..989c1639d44 100644
--- a/packages/site_shared/lib/components/common/chip.dart
+++ b/packages/site_shared/lib/components/common/chip.dart
@@ -25,7 +25,7 @@ class ChipSet extends StatelessComponent {
         id: 'reset-filters',
         classes: 'text-button',
         events: {'click': (_) => onReset()},
-        [const .text('Clear filters')],
+        const [.text('Clear filters')],
       ),
   ]);
 }
@@ -124,8 +124,8 @@ class FilterChip extends StatelessComponent {
               'viewBox': iconViewBox,
               'aria-hidden': 'true',
             },
-            [
-              const Component.element(
+            const [
+              Component.element(
                 tag: 'path',
                 attributes: {
                   'd':
@@ -244,7 +244,7 @@ class _SelectChipState<T> extends State<SelectChip<T>> {
                 width: 24.px,
                 height: 24.px,
                 viewBox: '0 0 24 24',
-                attributes: {'aria-hidden': 'true'},
+                attributes: const {'aria-hidden': 'true'},
                 [
                   Component.element(
                     tag: 'path',
@@ -322,7 +322,7 @@ class SelectMenuItem<T> {
               width: iconSize.px,
               height: iconSize.px,
               viewBox: iconViewBox,
-              attributes: {'aria-hidden': 'true'},
+              attributes: const {'aria-hidden': 'true'},
               [
                 Component.element(
                   tag: 'path',
diff --git a/packages/site_shared/lib/components/common/client/on_this_page_button.dart b/packages/site_shared/lib/components/common/client/on_this_page_button.dart
index 54057e24e31..6b90f207519 100644
--- a/packages/site_shared/lib/components/common/client/on_this_page_button.dart
+++ b/packages/site_shared/lib/components/common/client/on_this_page_button.dart
@@ -26,9 +26,9 @@ final class OnThisPageButton extends StatelessComponent {
         }
       },
     },
-    [
-      const MaterialIcon('list'),
-      const span([.text('On this page')]),
+    const [
+      MaterialIcon('list'),
+      span([.text('On this page')]),
     ],
   );
 }
diff --git a/packages/site_shared/lib/components/common/client/page_header_options.dart b/packages/site_shared/lib/components/common/client/page_header_options.dart
index 6a97eb187a7..d5e050126e7 100644
--- a/packages/site_shared/lib/components/common/client/page_header_options.dart
+++ b/packages/site_shared/lib/components/common/client/page_header_options.dart
@@ -143,7 +143,7 @@ final class _PageHeaderOptionsState extends State<PageHeaderOptions> {
     toggle: const Button(icon: 'more_vert', title: 'View page options.'),
     content: nav(
       classes: 'dropdown-menu',
-      attributes: {
+      attributes: const {
         'role': 'menu',
       },
       [
diff --git a/packages/site_shared/lib/components/common/fragment_target.dart b/packages/site_shared/lib/components/common/fragment_target.dart
index 0d706ebe9f3..573c0e74652 100644
--- a/packages/site_shared/lib/components/common/fragment_target.dart
+++ b/packages/site_shared/lib/components/common/fragment_target.dart
@@ -17,7 +17,7 @@ final class FragmentTarget extends StatelessComponent {
   Component build(BuildContext context) => a(
     href: '',
     id: id,
-    attributes: {'aria-hidden': 'true'},
-    [],
+    attributes: const {'aria-hidden': 'true'},
+    const [],
   );
 }
diff --git a/packages/site_shared/lib/components/common/ide_explorer/ide_explorer.dart b/packages/site_shared/lib/components/common/ide_explorer/ide_explorer.dart
index 0ac25b3dd21..a926e7a8da1 100644
--- a/packages/site_shared/lib/components/common/ide_explorer/ide_explorer.dart
+++ b/packages/site_shared/lib/components/common/ide_explorer/ide_explorer.dart
@@ -447,7 +447,7 @@ class _IdeBadgeDot extends StatelessComponent {
         'aria-label': badge,
         'title': badge,
       },
-      [],
+      const [],
     );
   }
 }
diff --git a/packages/site_shared/lib/components/common/tooltip.dart b/packages/site_shared/lib/components/common/tooltip.dart
index 3cdb63782bf..8f0a1b81635 100644
--- a/packages/site_shared/lib/components/common/tooltip.dart
+++ b/packages/site_shared/lib/components/common/tooltip.dart
@@ -24,15 +24,15 @@ class Tooltip extends StatefulComponent {
 }
 
 class _TooltipState extends State<Tooltip> {
-  static final isTouchscreen =
+  static final bool _isTouchscreen =
       kIsWeb && web.window.matchMedia('(pointer: coarse)').matches;
 
-  final wrapperKey = GlobalNodeKey<web.HTMLElement>();
-  final targetKey = GlobalNodeKey<web.HTMLElement>();
-  final tooltipKey = GlobalNodeKey<web.HTMLElement>();
+  final GlobalNodeKey<web.HTMLElement> _wrapperKey = GlobalNodeKey();
+  final GlobalNodeKey<web.HTMLElement> _targetKey = GlobalNodeKey();
+  final GlobalNodeKey<web.HTMLElement> _tooltipKey = GlobalNodeKey();
 
-  bool isVisible = false;
-  double tooltipOffset = 0.0;
+  bool _isVisible = false;
+  double _tooltipOffset = 0;
 
   @override
   void initState() {
@@ -55,29 +55,29 @@ class _TooltipState extends State<Tooltip> {
   /// Adjust the tooltip position to ensure it is fully inside the
   /// ancestor .content element.
   void ensureVisible() {
-    final target = targetKey.currentNode;
-    final tooltip = tooltipKey.currentNode;
+    final target = _targetKey.currentNode;
+    final tooltip = _tooltipKey.currentNode;
     if (tooltip == null || target == null) return;
 
     setState(() {
-      tooltipOffset = calculateTooltipOffset(target, tooltip);
+      _tooltipOffset = calculateTooltipOffset(target, tooltip);
     });
   }
 
   @override
   Component build(BuildContext context) {
     return span(
-      key: wrapperKey,
+      key: _wrapperKey,
       classes: 'tooltip-wrapper',
       [
         span(
-          key: targetKey,
+          key: _targetKey,
           classes: 'tooltip-target',
           events: {
-            if (isTouchscreen)
+            if (_isTouchscreen)
               'click': (e) {
-                if (!isVisible) {
-                  setState(() => isVisible = true);
+                if (!_isVisible) {
+                  setState(() => _isVisible = true);
                   e.preventDefault();
                 }
               },
@@ -87,33 +87,33 @@ class _TooltipState extends State<Tooltip> {
         if (component.content case final content?)
           GlobalEventListener(
             // Close tooltip when clicking outside of this wrapper.
-            onClick: isTouchscreen
+            onClick: _isTouchscreen
                 ? (e) {
-                    if (wrapperKey.currentNode?.contains(
+                    if (_wrapperKey.currentNode?.contains(
                           e.target as web.Node?,
                         ) ==
                         true) {
                       return;
                     }
-                    setState(() => isVisible = false);
+                    setState(() => _isVisible = false);
                   }
                 : null,
             // On touchscreen devices, close tooltips when scrolling.
-            onScroll: isTouchscreen
+            onScroll: _isTouchscreen
                 ? (_) {
-                    setState(() => isVisible = false);
+                    setState(() => _isVisible = false);
                   }
                 : null,
             span(
-              key: tooltipKey,
-              classes: ['tooltip', if (isVisible) 'visible'].toClasses,
+              key: _tooltipKey,
+              classes: ['tooltip', if (_isVisible) 'visible'].toClasses,
               styles: Styles(
                 raw: {
-                  'left': tooltipOffset == 0
+                  'left': _tooltipOffset == 0
                       ? '50%'
-                      : tooltipOffset > 0
-                      ? 'calc(50% + ${tooltipOffset}px)'
-                      : 'calc(50% - ${tooltipOffset.abs()}px)',
+                      : _tooltipOffset > 0
+                      ? 'calc(50% + ${_tooltipOffset}px)'
+                      : 'calc(50% - ${_tooltipOffset.abs()}px)',
                 },
               ),
               [
diff --git a/packages/site_shared/lib/components/common/youtube_embed.dart b/packages/site_shared/lib/components/common/youtube_embed.dart
index fffba49ec0e..ce6cc76a1a6 100644
--- a/packages/site_shared/lib/components/common/youtube_embed.dart
+++ b/packages/site_shared/lib/components/common/youtube_embed.dart
@@ -62,7 +62,7 @@ class YoutubeEmbed with CustomComponentBase {
           classes: 'lite-youtube-fallback',
           href: 'https://www.youtube.com/watch/$videoId',
           target: Target.blank,
-          attributes: {'rel': 'noopener'},
+          attributes: const {'rel': 'noopener'},
           [
             .text('Watch on YouTube in a new tab: "$videoTitle"'),
           ],
diff --git a/packages/site_shared/lib/components/dartpad/embedded_dartpad.dart b/packages/site_shared/lib/components/dartpad/embedded_dartpad.dart
index 1aa7b0d3e88..faa4dd5bdb8 100644
--- a/packages/site_shared/lib/components/dartpad/embedded_dartpad.dart
+++ b/packages/site_shared/lib/components/dartpad/embedded_dartpad.dart
@@ -147,7 +147,7 @@ class _EmbeddedDartPadState extends State<EmbeddedDartPad> {
       src: component._iframeUrl,
       loading: MediaLoading.lazy,
       allow: 'clipboard-write',
-      [],
+      const [],
     );
   }
 }
diff --git a/packages/site_shared/lib/components/layout/site_switcher.dart b/packages/site_shared/lib/components/layout/site_switcher.dart
index f968a421452..36405e6d458 100644
--- a/packages/site_shared/lib/components/layout/site_switcher.dart
+++ b/packages/site_shared/lib/components/layout/site_switcher.dart
@@ -22,7 +22,7 @@ final class SiteSwitcher extends StatelessComponent {
       toggle: const Button(icon: 'apps', title: 'Visit related sites.'),
       content: nav(
         classes: 'dropdown-menu',
-        attributes: {'role': 'menu'},
+        attributes: const {'role': 'menu'},
         [
           ul([
             if (isFlutter) ...[
@@ -124,7 +124,7 @@ class _SiteWordMarkListEntry extends StatelessComponent {
               ),
             span(
               classes: 'name',
-              attributes: {
+              attributes: const {
                 'translate': 'no',
               },
               [.text(name)],
diff --git a/packages/site_shared/lib/components/tutorial/client/progress_ring.dart b/packages/site_shared/lib/components/tutorial/client/progress_ring.dart
index d208f56557a..9903a48417f 100644
--- a/packages/site_shared/lib/components/tutorial/client/progress_ring.dart
+++ b/packages/site_shared/lib/components/tutorial/client/progress_ring.dart
@@ -66,7 +66,7 @@ class InteractiveProgressRing extends StatelessComponent {
               'stroke-dasharray': '$inactiveLength ${full - inactiveLength}',
               'stroke-dashoffset': '${quarter - activeLength - gap * 1.5}',
             },
-            [],
+            const [],
           ),
 
         // Active portion, drawn from 0° to (progress)°
@@ -80,7 +80,7 @@ class InteractiveProgressRing extends StatelessComponent {
             'stroke-dasharray': '$activeLength ${full - activeLength}',
             'stroke-dashoffset': '${quarter - gap / 2}',
           },
-          [],
+          const [],
         ),
       ],
     );
diff --git a/packages/site_shared/lib/src/utils/retake_element_web.dart b/packages/site_shared/lib/src/utils/retake_element_web.dart
index 5631e5ac73f..37de584eeb8 100644
--- a/packages/site_shared/lib/src/utils/retake_element_web.dart
+++ b/packages/site_shared/lib/src/utils/retake_element_web.dart
@@ -56,6 +56,9 @@ String extractContent(Element element) {
 }
 
 class RawNode extends Component {
+  // Identity is important to these components and a
+  // web node can't be retrieved at compile time anyway.
+  // ignore: prefer_const_constructors_in_immutables
   RawNode(this.node, {super.key});
 
   final web.Node node;
diff --git a/sites/docs/lib/src/components/layout/toc.dart b/sites/docs/lib/src/components/layout/toc.dart
index 0cd4075f9d7..d0ae1ab30b8 100644
--- a/sites/docs/lib/src/components/layout/toc.dart
+++ b/sites/docs/lib/src/components/layout/toc.dart
@@ -82,7 +82,7 @@ final class PageNavBar extends StatelessComponent {
             const _DropdownDivider(),
             if (data.toc case final tocData?)
               nav(
-                attributes: {'role': 'menu'},
+                attributes: const {'role': 'menu'},
                 [_TocContents(tocData)],
               ),
           ] else ...[
@@ -108,7 +108,7 @@ final class PageNavBar extends StatelessComponent {
                     if (page == currentLinkedPage) 'active',
                   ].toClasses,
                   href: page.url,
-                  attributes: {'role': 'menuitem'},
+                  attributes: const {'role': 'menuitem'},
                   [
                     span(classes: 'page-number', [
                       .text('${pageEntryNumber++}'),
@@ -118,7 +118,7 @@ final class PageNavBar extends StatelessComponent {
                 ),
                 if (data.toc case final tocData? when currentLinkedPage == page)
                   nav(
-                    attributes: {'role': 'menu'},
+                    attributes: const {'role': 'menu'},
                     [_TocContents(tocData)],
                   ),
               ] else ...[
diff --git a/sites/docs/lib/src/components/layout/trailing_content.dart b/sites/docs/lib/src/components/layout/trailing_content.dart
index 2efcfc836a8..4cd9ab996cb 100644
--- a/sites/docs/lib/src/components/layout/trailing_content.dart
+++ b/sites/docs/lib/src/components/layout/trailing_content.dart
@@ -48,8 +48,8 @@ class TrailingContent extends StatelessComponent {
           if (pageSource != null) ...[
             a(
               href: pageSource,
-              attributes: {'target': '_blank', 'rel': 'noopener'},
-              [const .text('View source')],
+              attributes: const {'target': '_blank', 'rel': 'noopener'},
+              const [.text('View source')],
             ),
             const span([.text(' or ')]),
           ],
diff --git a/sites/docs/lib/src/components/pages/architecture_recommendations.dart b/sites/docs/lib/src/components/pages/architecture_recommendations.dart
index 39bbd04db7d..91faabffcd3 100644
--- a/sites/docs/lib/src/components/pages/architecture_recommendations.dart
+++ b/sites/docs/lib/src/components/pages/architecture_recommendations.dart
@@ -54,11 +54,11 @@ class ArchitectureRecommendations extends CustomComponentBase {
           [
             thead([
               tr([
-                th(styles: Styles(width: 30.percent), [
-                  const .text('Recommendation'),
+                th(styles: Styles(width: 30.percent), const [
+                  .text('Recommendation'),
                 ]),
-                th(styles: Styles(width: 70.percent), [
-                  const .text('Description'),
+                th(styles: Styles(width: 70.percent), const [
+                  .text('Description'),
                 ]),
               ]),
             ]),
diff --git a/sites/docs/lib/src/components/pages/archive_table.dart b/sites/docs/lib/src/components/pages/archive_table.dart
index fc31805cbdf..7f22bf08b4b 100644
--- a/sites/docs/lib/src/components/pages/archive_table.dart
+++ b/sites/docs/lib/src/components/pages/archive_table.dart
@@ -148,16 +148,16 @@ class _ArchiveTableState extends State<ArchiveTable> {
     ]);
   }
 
-  static final windowsCutoff = Date.parse('4/3/2023');
-  static final otherOsCutoff = Date.parse('12/15/2022');
+  static final int _windowsCutoff = Date.parse('4/3/2023');
+  static final int _otherOsCutoff = Date.parse('12/15/2022');
 
   Component buildProvenanceLink(FlutterRelease release) {
     final dateValue = release.releaseDate.valueOf();
 
-    if (os == 'windows' && dateValue < windowsCutoff) {
+    if (os == 'windows' && dateValue < _windowsCutoff) {
       // Provenance not available before 4/3/2023 for Windows
       return const span([.text('-')]);
-    } else if (dateValue < otherOsCutoff) {
+    } else if (dateValue < _otherOsCutoff) {
       // Provenance not available before 12/15/2022 for macOS and Linux
       return const span([.text('-')]);
     }
@@ -169,7 +169,7 @@ class _ArchiveTableState extends State<ArchiveTable> {
           'flutter_${os}_${release.version}-$channel.'
           '$archiveExtension.intoto.jsonl',
       target: Target.blank,
-      [const .text('Attestation bundle')],
+      const [.text('Attestation bundle')],
     );
   }
 }
diff --git a/sites/docs/lib/src/components/pages/expansion_list.dart b/sites/docs/lib/src/components/pages/expansion_list.dart
index 0fd52bb89d3..a16889c7aad 100644
--- a/sites/docs/lib/src/components/pages/expansion_list.dart
+++ b/sites/docs/lib/src/components/pages/expansion_list.dart
@@ -170,8 +170,8 @@ class _ExpansionListState extends State<ExpansionList> {
             [
               DashMarkdown(content: item.content),
               p([
-                a(href: item.url, [
-                  const .text('Read full article'),
+                a(href: item.url, const [
+                  .text('Read full article'),
                 ]),
               ]),
               // Required to add "margin" that doesn't cause expansion jank.
diff --git a/sites/docs/lib/src/components/pages/learning_resource_index.dart b/sites/docs/lib/src/components/pages/learning_resource_index.dart
index 311ef620a49..335e7c01212 100644
--- a/sites/docs/lib/src/components/pages/learning_resource_index.dart
+++ b/sites/docs/lib/src/components/pages/learning_resource_index.dart
@@ -94,8 +94,8 @@ final class _ResourceCard extends StatelessComponent {
       classes: 'monochrome-icon',
       width: 24.px,
       height: 24.px,
-      [
-        const Component.element(
+      const [
+        Component.element(
           tag: 'use',
           attributes: {'href': '/assets/images/social/github.svg#github'},
         ),
@@ -106,8 +106,8 @@ final class _ResourceCard extends StatelessComponent {
       width: 24,
       alt: 'Dart logo',
     ),
-    'Google Codelab' => svg(width: 24.px, height: 24.px, [
-      const Component.element(
+    'Google Codelab' => svg(width: 24.px, height: 24.px, const [
+      Component.element(
         tag: 'use',
         attributes: {
           'href':
@@ -119,8 +119,8 @@ final class _ResourceCard extends StatelessComponent {
       attributes: {'style': 'color: red'},
       width: 24.px,
       height: 24.px,
-      [
-        const Component.element(
+      const [
+        Component.element(
           tag: 'use',
           attributes: {'href': '/assets/images/social/youtube.svg#youtube'},
         ),
diff --git a/sites/docs/lib/src/components/pages/widget_catalog.dart b/sites/docs/lib/src/components/pages/widget_catalog.dart
index fb744f58401..1bee8f5d58f 100644
--- a/sites/docs/lib/src/components/pages/widget_catalog.dart
+++ b/sites/docs/lib/src/components/pages/widget_catalog.dart
@@ -141,7 +141,7 @@ class WidgetCatalogCard extends StatelessComponent {
         ? {'style': '--bg-color: ${subcategory?.color}'}
         : <String, String>{};
 
-    final placeholder = const img(
+    const placeholderImage = img(
       alt:
           'Placeholder Flutter logo in place of '
           'missing widget image or visualization.',
@@ -158,7 +158,7 @@ class WidgetCatalogCard extends StatelessComponent {
           if (widget.imageSrc case final imageSrc? when imageSrc.isNotEmpty)
             img(alt: imageAlt, src: imageSrc)
           else
-            placeholder,
+            placeholderImage,
           if (widget.hoverBackgroundSrc case final hoverBackgroundSrc?
               when hoverBackgroundSrc.isNotEmpty)
             div(classes: 'card-image-material-3-hover', [
@@ -178,7 +178,7 @@ class WidgetCatalogCard extends StatelessComponent {
               when imageSrc.isNotEmpty)
             img(alt: imageAlt, src: imageSrc)
           else
-            placeholder,
+            placeholderImage,
         ],
       ],
     );
diff --git a/sites/docs/lib/src/extensions/glossary_link_processor.dart b/sites/docs/lib/src/extensions/glossary_link_processor.dart
index af86e036278..2119a50ba48 100644
--- a/sites/docs/lib/src/extensions/glossary_link_processor.dart
+++ b/sites/docs/lib/src/extensions/glossary_link_processor.dart
@@ -94,7 +94,7 @@ class GlossaryTooltipContent extends StatelessComponent {
                 'Learn more about \'${entry.term}\' and '
                 'find related resources.',
           },
-          [const .text('Learn more')],
+          const [.text('Learn more')],
         ),
       ]),
     ]);
diff --git a/sites/docs/lib/src/extensions/tutorial_structure_processor.dart b/sites/docs/lib/src/extensions/tutorial_structure_processor.dart
index 856123a0550..07a70935b22 100644
--- a/sites/docs/lib/src/extensions/tutorial_structure_processor.dart
+++ b/sites/docs/lib/src/extensions/tutorial_structure_processor.dart
@@ -112,7 +112,7 @@ final class TutorialStructureExtension implements PageExtension {
 
   /// Checks if a node is a YouTube video embed
   bool _isVideoEmbed(Node node) {
-    if (node case ElementNode(tag: final tag)) {
+    if (node case ElementNode(:final tag)) {
       final lowerTag = tag.toLowerCase();
       return lowerTag == 'youtubeembed' || lowerTag == 'lite-youtube';
     }
diff --git a/sites/www/lib/main.server.dart b/sites/www/lib/main.server.dart
index 7ff40b2b175..73a77adc2fc 100644
--- a/sites/www/lib/main.server.dart
+++ b/sites/www/lib/main.server.dart
@@ -45,7 +45,7 @@ import 'src/pages/showcase_page.dart';
 import 'src/pages/web_page.dart';
 import 'src/utils/asset_utils.dart';
 
-void main() async {
+void main() {
   Jaspr.initializeApp(options: defaultServerOptions);
 
   final assetManager = AssetManager(
@@ -54,7 +54,7 @@ void main() async {
     dataProperties: const {'page.image', 'page.socialImage'},
     assetTransformers: [
       TrackingAssetTransformer(),
-      ResizingAssetTransformer(),
+      const ResizingAssetTransformer(),
       const HashingAssetTransformer(),
     ],
   );
diff --git a/sites/www/lib/src/components/common/newsletter_form.dart b/sites/www/lib/src/components/common/newsletter_form.dart
index 58eca36fb10..d239a649998 100644
--- a/sites/www/lib/src/components/common/newsletter_form.dart
+++ b/sites/www/lib/src/components/common/newsletter_form.dart
@@ -133,7 +133,7 @@ class _NewsletterFormState extends State<NewsletterForm> {
 
   Future<void> _sendData() async {
     try {
-      // Create multipart request for form submission
+      // Create multipart request for form submission.
       final request = http.MultipartRequest('POST', Uri.parse(_formUrl));
 
       request.fields['EmailAddress'] = _email;
@@ -147,7 +147,7 @@ class _NewsletterFormState extends State<NewsletterForm> {
       final response = await http.Response.fromStream(streamedResponse);
 
       if (response.statusCode == 200) {
-        final jsonData = jsonDecode(response.body);
+        final jsonData = jsonDecode(response.body) as Object?;
 
         if (jsonData case {'errors': final Map<String, Object?> serverErrors}) {
           _reverseSetErrors(serverErrors);
diff --git a/sites/www/lib/src/utils/asset_utils.dart b/sites/www/lib/src/utils/asset_utils.dart
index 19395751d99..d18587c3e1d 100644
--- a/sites/www/lib/src/utils/asset_utils.dart
+++ b/sites/www/lib/src/utils/asset_utils.dart
@@ -16,9 +16,7 @@ extension AssetExtension on BuildContext {
 }
 
 class TrackingAssetTransformer implements AssetTransformer {
-  TrackingAssetTransformer();
-
-  final _trackingFile = File(
+  final IOSink _trackingFile = File(
     p.join('tool', 'used_assets.txt'),
   ).openWrite(mode: FileMode.write);
 
@@ -30,6 +28,8 @@ class TrackingAssetTransformer implements AssetTransformer {
 }
 
 class ResizingAssetTransformer implements AssetTransformer {
+  const ResizingAssetTransformer();
+
   @override
   Asset transform(Asset asset, [Object? aspect]) {
     final width = aspect is int ? aspect : null;
diff --git a/sites/www/tool/get_video_transcript.dart b/sites/www/tool/get_video_transcript.dart
index aefb71c3db1..4055f5a89c7 100644
--- a/sites/www/tool/get_video_transcript.dart
+++ b/sites/www/tool/get_video_transcript.dart
@@ -87,13 +87,13 @@ String? _youtubeVideoIdFromUrl(String url) {
 String _formatTimestamp(int seconds) {
   final hours = seconds ~/ 3600;
   final minutes = (seconds % 3600) ~/ 60;
-  final secs = (seconds % 60).toInt();
+  final secondsInMinute = seconds % 60;
 
   String pad(int n) => n.toString().padLeft(2, '0');
 
   if (hours > 0) {
-    return '[${pad(hours)}:${pad(minutes)}:${pad(secs)}]';
+    return '[${pad(hours)}:${pad(minutes)}:${pad(secondsInMinute)}]';
   } else {
-    return '[${pad(minutes)}:${pad(secs)}]';
+    return '[${pad(minutes)}:${pad(secondsInMinute)}]';
   }
 }
diff --git a/tool/dash_site/lib/src/commands/build.dart b/tool/dash_site/lib/src/commands/build.dart
index 25904d6dd69..c93b8bb578b 100644
--- a/tool/dash_site/lib/src/commands/build.dart
+++ b/tool/dash_site/lib/src/commands/build.dart
@@ -30,7 +30,7 @@ final class BuildSiteCommand extends Command<int> {
   String get name => 'build';
 
   @override
-  Future<int> run() async => buildSite(
+  Future<int> run() => buildSite(
     selectedSite,
     productionRelease: argResults.get<bool>(_releaseFlag, false),
   );
diff --git a/tool/dash_site/lib/src/commands/check_link_references.dart b/tool/dash_site/lib/src/commands/check_link_references.dart
index fb0d540d893..b41a4c340cb 100644
--- a/tool/dash_site/lib/src/commands/check_link_references.dart
+++ b/tool/dash_site/lib/src/commands/check_link_references.dart
@@ -83,18 +83,21 @@ Map<String, List<String>> _findInvalidLinkReferences(Directory directory) {
 }
 
 List<String> _findInContent(String content) {
+  var transformedContent = content;
   for (final replacement in _allReplacements) {
-    content = content.replaceAll(replacement, '');
+    transformedContent = transformedContent.replaceAll(replacement, '');
   }
 
-  // Use regex to find all links that displayed abnormally,
+  // Use a regular expression to find all links that displayed abnormally,
   // since a valid reference link should be an `<a>` tag after rendered:
   //
   // - `[flutter.dev][]`
   // - `[GitHub repo][repo]`
   // See also:
   // - https://github.github.com/gfm/#reference-link
-  final invalidFound = _invalidLinkReferencePattern.allMatches(content);
+  final invalidFound = _invalidLinkReferencePattern.allMatches(
+    transformedContent,
+  );
 
   if (invalidFound.isEmpty) {
     return const [];
@@ -111,14 +114,14 @@ List<String> _findInContent(String content) {
 /// ```html
 /// <!-- TODO(somebody): [Links here][are not rendered]. -->
 /// ```
-final _htmlCommentPattern = RegExp(r'<!--.*?-->', dotAll: true);
+final RegExp _htmlCommentPattern = RegExp(r'<!--.*?-->', dotAll: true);
 
 /// Ignore blocks with code:
 ///
 /// ```dart
 /// [[highlight]]flutter[[/highlight]]
 /// ```
-final _codeBlockPattern = RegExp(r'<pre.*?</pre>', dotAll: true);
+final RegExp _codeBlockPattern = RegExp(r'<pre.*?</pre>', dotAll: true);
 
 /// Ignore PR titles that look like a link
 /// directly embedded in a paragraph
@@ -130,7 +133,7 @@ final _codeBlockPattern = RegExp(r'<pre.*?</pre>', dotAll: true);
 /// (cla: yes, waiting for tree to go green, platform-web, needs tests)
 /// </p>
 /// ```
-final _pullRequestTitlePattern = RegExp(
+final RegExp _pullRequestTitlePattern = RegExp(
   r'<p><a href="https://github.com/.*?/pull/\d+">\d+</a>.*?</p>',
   dotAll: true,
 );
@@ -143,17 +146,17 @@ final _pullRequestTitlePattern = RegExp(
 /// <li>[docs][FWW] DropdownButton, ScaffoldMessenger, and StatefulBuilder links
 /// by @craiglabenz in https://github.com/flutter/flutter/pull/100316</li>
 /// ```
-final _pullRequestTitleInListItemPattern = RegExp(
+final RegExp _pullRequestTitleInListItemPattern = RegExp(
   r'<li>(?:(?!<li>).)*?in\s+(?:(?!<li>).)*?</li>',
   dotAll: true,
 );
 
 /// All replacements to run on a file content before finding invalid references.
-final _allReplacements = [
+final List<RegExp> _allReplacements = [
   _htmlCommentPattern,
   _codeBlockPattern,
   _pullRequestTitlePattern,
   _pullRequestTitleInListItemPattern,
 ];
 
-final _invalidLinkReferencePattern = RegExp(r'\[[^\[\]]+]\[[^\[\]]*]');
+final RegExp _invalidLinkReferencePattern = RegExp(r'\[[^\[\]]+]\[[^\[\]]*]');
diff --git a/tool/dash_site/lib/src/commands/check_links.dart b/tool/dash_site/lib/src/commands/check_links.dart
index 112cd9cd81a..769e09c8586 100644
--- a/tool/dash_site/lib/src/commands/check_links.dart
+++ b/tool/dash_site/lib/src/commands/check_links.dart
@@ -32,7 +32,7 @@ final class CheckLinksCommand extends Command<int> {
   String get name => 'check-links';
 
   @override
-  Future<int> run() async => _checkLinks(
+  Future<int> run() => _checkLinks(
     site: selectedSite,
     checkExternal: argResults.get<bool>(_externalFlag, false),
   );
diff --git a/tool/dash_site/lib/src/commands/deploy.dart b/tool/dash_site/lib/src/commands/deploy.dart
index 32e15181080..858b24aef76 100644
--- a/tool/dash_site/lib/src/commands/deploy.dart
+++ b/tool/dash_site/lib/src/commands/deploy.dart
@@ -75,6 +75,6 @@ final class DeployCommand extends Command<int> {
       workingDirectory: path.join(repositoryRoot, selectedSite.directory),
       mode: ProcessStartMode.inheritStdio,
     );
-    return deploy.exitCode;
+    return await deploy.exitCode;
   }
 }
diff --git a/tool/dash_site/lib/src/commands/refresh_excerpts.dart b/tool/dash_site/lib/src/commands/refresh_excerpts.dart
index 3f204bf44f3..c9c77cfcff9 100644
--- a/tool/dash_site/lib/src/commands/refresh_excerpts.dart
+++ b/tool/dash_site/lib/src/commands/refresh_excerpts.dart
@@ -42,7 +42,7 @@ final class RefreshExcerptsCommand extends Command<int> {
   String get name => 'refresh-excerpts';
 
   @override
-  Future<int> run() async => _refreshExcerpts(
+  Future<int> run() => _refreshExcerpts(
     site: selectedSite,
     verboseLogging: argResults.get<bool>(_verboseFlag, false),
     dryRun: argResults.get<bool>(_dryRunFlag, false),
diff --git a/tool/dash_site/lib/src/commands/stage_preview.dart b/tool/dash_site/lib/src/commands/stage_preview.dart
index 0feb2e9842f..8da6f5c286e 100644
--- a/tool/dash_site/lib/src/commands/stage_preview.dart
+++ b/tool/dash_site/lib/src/commands/stage_preview.dart
@@ -179,7 +179,7 @@ final class StagePreviewCommand extends Command<int> {
       return 0;
     }
 
-    return _commentStagingUrlOnGitHub(
+    return await _commentStagingUrlOnGitHub(
       site: selectedSite,
       stagingUrl: stagingUrl,
       context: prContext,
diff --git a/tool/dash_site/lib/src/commands/test_dart.dart b/tool/dash_site/lib/src/commands/test_dart.dart
index 3f86771a5a7..00195d8a8c6 100644
--- a/tool/dash_site/lib/src/commands/test_dart.dart
+++ b/tool/dash_site/lib/src/commands/test_dart.dart
@@ -28,7 +28,7 @@ final class TestDartCommand extends Command<int> {
   String get name => 'test-dart';
 
   @override
-  Future<int> run() async =>
+  Future<int> run() =>
       _testDart(verboseLogging: argResults.get<bool>(_verboseFlag, false));
 }