diff --git a/front_end/core/sdk/DOMModel.ts b/front_end/core/sdk/DOMModel.ts
index c0c1f57907..dcf56ab2a2 100644
--- a/front_end/core/sdk/DOMModel.ts
+++ b/front_end/core/sdk/DOMModel.ts
@@ -808,9 +808,9 @@ export class DOMNode {
     traverse(this);
   }
 
-  resolveURL(url: string): string|null {
+  resolveURL(url: string): Platform.DevToolsPath.UrlString|null {
     if (!url) {
-      return url;
+      return url as Platform.DevToolsPath.UrlString;
     }
     for (let frameOwnerCandidate: (DOMNode|null) = (this as DOMNode | null); frameOwnerCandidate;
          frameOwnerCandidate = frameOwnerCandidate.parentNode) {
diff --git a/front_end/panels/coverage/CoverageListView.ts b/front_end/panels/coverage/CoverageListView.ts
index 8adaafc212..cceff290b6 100644
--- a/front_end/panels/coverage/CoverageListView.ts
+++ b/front_end/panels/coverage/CoverageListView.ts
@@ -266,9 +266,7 @@ export class CoverageListView extends UI.Widget.VBox {
       return;
     }
     const coverageInfo = (node as GridNode).coverageInfo;
-    // TODO(crbug.com/1253323): Cast to UrlString will be removed when migration to branded types is complete.
-    let sourceCode = Workspace.Workspace.WorkspaceImpl.instance().uiSourceCodeForURL(
-        coverageInfo.url() as Platform.DevToolsPath.UrlString);
+    let sourceCode = Workspace.Workspace.WorkspaceImpl.instance().uiSourceCodeForURL(coverageInfo.url());
     if (!sourceCode) {
       return;
     }
@@ -317,7 +315,7 @@ function getPercentageFormatter(): Intl.NumberFormat {
 export class GridNode extends DataGrid.SortableDataGrid.SortableDataGridNode<GridNode> {
   coverageInfo: URLCoverageInfo;
   private lastUsedSize!: number|undefined;
-  private url: string;
+  private url: Platform.DevToolsPath.UrlString;
   private maxSize: number;
   private highlightRegExp: RegExp|null;
 
diff --git a/front_end/panels/coverage/CoverageModel.ts b/front_end/panels/coverage/CoverageModel.ts
index 4dc63bb70d..fe635824e7 100644
--- a/front_end/panels/coverage/CoverageModel.ts
+++ b/front_end/panels/coverage/CoverageModel.ts
@@ -44,7 +44,7 @@ export class CoverageModel extends SDK.SDKModel.SDKModel<EventTypes> {
   private cpuProfilerModel: SDK.CPUProfilerModel.CPUProfilerModel|null;
   private cssModel: SDK.CSSModel.CSSModel|null;
   private debuggerModel: SDK.DebuggerModel.DebuggerModel|null;
-  private coverageByURL: Map<string, URLCoverageInfo>;
+  private coverageByURL: Map<Platform.DevToolsPath.UrlString, URLCoverageInfo>;
   private coverageByContentProvider: Map<TextUtils.ContentProvider.ContentProvider, CoverageInfo>;
   private coverageUpdateTimes: Set<number>;
   private suspensionState: SuspensionState;
@@ -216,7 +216,7 @@ export class CoverageModel extends SDK.SDKModel.SDKModel<EventTypes> {
     return Array.from(this.coverageByURL.values());
   }
 
-  getCoverageForUrl(url: string): URLCoverageInfo|null {
+  getCoverageForUrl(url: Platform.DevToolsPath.UrlString): URLCoverageInfo|null {
     return this.coverageByURL.get(url) || null;
   }
 
@@ -482,7 +482,7 @@ export class CoverageModel extends SDK.SDKModel.SDKModel<EventTypes> {
 SDK.SDKModel.SDKModel.register(CoverageModel, {capabilities: SDK.Target.Capability.None, autostart: false});
 
 export interface EntryForExport {
-  url: string;
+  url: Platform.DevToolsPath.UrlString;
   ranges: {start: number, end: number}[];
   text: string|null;
 }
@@ -495,14 +495,14 @@ function locationCompare(a: string, b: string): number {
 }
 
 export class URLCoverageInfo extends Common.ObjectWrapper.ObjectWrapper<URLCoverageInfo.EventTypes> {
-  private readonly urlInternal: string;
+  private readonly urlInternal: Platform.DevToolsPath.UrlString;
   private coverageInfoByLocation: Map<string, CoverageInfo>;
   private sizeInternal: number;
   private usedSizeInternal: number;
   private typeInternal!: CoverageType;
   private isContentScriptInternal: boolean;
 
-  constructor(url: string) {
+  constructor(url: Platform.DevToolsPath.UrlString) {
     super();
 
     this.urlInternal = url;
@@ -512,7 +512,7 @@ export class URLCoverageInfo extends Common.ObjectWrapper.ObjectWrapper<URLCover
     this.isContentScriptInternal = false;
   }
 
-  url(): string {
+  url(): Platform.DevToolsPath.UrlString {
     return this.urlInternal;
   }
 
@@ -618,8 +618,7 @@ export class URLCoverageInfo extends Common.ObjectWrapper.ObjectWrapper<URLCover
     if (!useFullText) {
       return null;
     }
-    // TODO(crbug.com/1253323): Cast to UrlString will be removed when migration to branded types is complete.
-    const resource = SDK.ResourceTreeModel.ResourceTreeModel.resourceForURL(url as Platform.DevToolsPath.UrlString);
+    const resource = SDK.ResourceTreeModel.ResourceTreeModel.resourceForURL(url);
     if (!resource) {
       return null;
     }
diff --git a/front_end/panels/elements/ImagePreviewPopover.ts b/front_end/panels/elements/ImagePreviewPopover.ts
index 659f9d25bc..33ddc40486 100644
--- a/front_end/panels/elements/ImagePreviewPopover.ts
+++ b/front_end/panels/elements/ImagePreviewPopover.ts
@@ -60,14 +60,14 @@ export class ImagePreviewPopover {
     this.popover.hidePopover();
   }
 
-  static setImageUrl(element: Element, url: string): Element {
+  static setImageUrl(element: Element, url: Platform.DevToolsPath.UrlString): Element {
     elementToURLMap.set(element, url);
     return element;
   }
 
-  static getImageURL(element: Element): string|undefined {
+  static getImageURL(element: Element): Platform.DevToolsPath.UrlString|undefined {
     return elementToURLMap.get(element);
   }
 }
 
-const elementToURLMap = new WeakMap<Element, string>();
+const elementToURLMap = new WeakMap<Element, Platform.DevToolsPath.UrlString>();
diff --git a/front_end/panels/elements/StylesSidebarPane.ts b/front_end/panels/elements/StylesSidebarPane.ts
index e2c51c8e20..1b909953a9 100644
--- a/front_end/panels/elements/StylesSidebarPane.ts
+++ b/front_end/panels/elements/StylesSidebarPane.ts
@@ -31,8 +31,6 @@
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-// TODO(crbug.com/1253323): Casts to UrlString will be removed from this file when migration to branded types is complete.
-
 import * as Common from '../../core/common/common.js';
 import * as Host from '../../core/host/host.js';
 import * as i18n from '../../core/i18n/i18n.js';
@@ -260,7 +258,7 @@ export class StylesSidebarPane extends Common.ObjectWrapper.eventMixin<EventType
   private readonly resizeThrottler: Common.Throttler.Throttler;
   private readonly imagePreviewPopover: ImagePreviewPopover;
   activeCSSAngle: InlineEditor.CSSAngle.CSSAngle|null;
-  #urlToChangeTracker: Map<string, ChangeTracker> = new Map();
+  #urlToChangeTracker: Map<Platform.DevToolsPath.UrlString, ChangeTracker> = new Map();
 
   static instance(): StylesSidebarPane {
     if (!stylesSidebarPaneInstance) {
@@ -1087,7 +1085,7 @@ export class StylesSidebarPane extends Common.ObjectWrapper.eventMixin<EventType
     return sections;
   }
 
-  async trackURLForChanges(url: string): Promise<void> {
+  async trackURLForChanges(url: Platform.DevToolsPath.UrlString): Promise<void> {
     const currentTracker = this.#urlToChangeTracker.get(url);
     if (currentTracker) {
       WorkspaceDiff.WorkspaceDiff.workspaceDiff().unsubscribeFromDiffChange(
@@ -1095,8 +1093,7 @@ export class StylesSidebarPane extends Common.ObjectWrapper.eventMixin<EventType
     }
 
     // We get a refreshed uiSourceCode each time because the underlying instance may be recreated.
-    const uiSourceCode =
-        Workspace.Workspace.WorkspaceImpl.instance().uiSourceCodeForURL(url as Platform.DevToolsPath.UrlString);
+    const uiSourceCode = Workspace.Workspace.WorkspaceImpl.instance().uiSourceCodeForURL(url);
     if (!uiSourceCode) {
       return;
     }
@@ -3394,14 +3391,14 @@ export class StylesSidebarPropertyRenderer {
 
   private processURL(text: string): Node {
     // Strip "url(" and ")" along with whitespace.
-    let url = text.substring(4, text.length - 1).trim();
+    let url = text.substring(4, text.length - 1).trim() as Platform.DevToolsPath.UrlString;
     const isQuoted = /^'.*'$/s.test(url) || /^".*"$/s.test(url);
     if (isQuoted) {
-      url = url.substring(1, url.length - 1);
+      url = Common.ParsedURL.ParsedURL.substring(url, 1, url.length - 1);
     }
     const container = document.createDocumentFragment();
     UI.UIUtils.createTextChild(container, 'url(');
-    let hrefUrl: (string|null)|null = null;
+    let hrefUrl: Platform.DevToolsPath.UrlString|null = null;
     if (this.rule && this.rule.resourceURL()) {
       hrefUrl = Common.ParsedURL.ParsedURL.completeURL(this.rule.resourceURL(), url);
     } else if (this.node) {
diff --git a/front_end/panels/network/NetworkDataGridNode.ts b/front_end/panels/network/NetworkDataGridNode.ts
index 6588822636..825c716552 100644
--- a/front_end/panels/network/NetworkDataGridNode.ts
+++ b/front_end/panels/network/NetworkDataGridNode.ts
@@ -1183,9 +1183,7 @@ export class NetworkRequestNode extends NetworkNode {
     switch (initiator.type) {
       case SDK.NetworkRequest.InitiatorType.Parser: {
         UI.Tooltip.Tooltip.install(cell, initiator.url + ':' + (initiator.lineNumber + 1));
-        // TODO(crbug.com/1253323): Cast to UrlString will be removed when migration to branded types is complete.
-        const uiSourceCode = Workspace.Workspace.WorkspaceImpl.instance().uiSourceCodeForURL(
-            initiator.url as Platform.DevToolsPath.UrlString);
+        const uiSourceCode = Workspace.Workspace.WorkspaceImpl.instance().uiSourceCodeForURL(initiator.url);
         cell.appendChild(
             Components.Linkifier.Linkifier.linkifyURL(initiator.url, ({
                                                         text: uiSourceCode ? uiSourceCode.displayName() : undefined,
diff --git a/front_end/panels/sources/CoveragePlugin.ts b/front_end/panels/sources/CoveragePlugin.ts
index 1ebef69f30..5767aa0dcb 100644
--- a/front_end/panels/sources/CoveragePlugin.ts
+++ b/front_end/panels/sources/CoveragePlugin.ts
@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 import * as i18n from '../../core/i18n/i18n.js';
+import type * as Platform from '../../core/platform/platform.js';
 import * as SDK from '../../core/sdk/sdk.js';
 import * as Formatter from '../../models/formatter/formatter.js';
 import type * as Workspace from '../../models/workspace/workspace.js';
@@ -190,7 +191,7 @@ const coverageState = CodeMirror.StateField.define<CodeMirror.RangeSet<CodeMirro
   },
 });
 
-function coverageGutter(url: string): CodeMirror.Extension {
+function coverageGutter(url: Platform.DevToolsPath.UrlString): CodeMirror.Extension {
   return CodeMirror.gutter({
     markers: (view): CodeMirror.RangeSet<CodeMirror.GutterMarker> => view.state.field(coverageState),