diff --git a/src/vs/platform/environment/node/environmentService.ts b/src/vs/platform/environment/node/environmentService.ts
index 0aad1cf390df3b0be9bfb9f69f0a5138133515eb..f1a9107e9032c03871c1d3fea6211d9c34c4f3a3 100644
--- a/src/vs/platform/environment/node/environmentService.ts
+++ b/src/vs/platform/environment/node/environmentService.ts
@@ -278,7 +278,7 @@ export class EnvironmentService implements IEnvironmentService {
 	get driverHandle(): string | undefined { return this._args['driver']; }
 	get driverVerbose(): boolean { return !!this._args['driver-verbose']; }
 
-	readonly webviewResourceRoot = 'vscode-resource:';
+	readonly webviewResourceRoot = 'vscode-resource:{{resource}}';
 	readonly webviewCspRule = 'vscode-resource:';
 
 	constructor(private _args: ParsedArgs, private _execPath: string) {
diff --git a/src/vs/workbench/api/common/extHostCodeInsets.ts b/src/vs/workbench/api/common/extHostCodeInsets.ts
index 49ba7410c643e122aa5279ce08c6858163e9461b..e744e87aa314663f67a276ac48f3deb1ad95ffc0 100644
--- a/src/vs/workbench/api/common/extHostCodeInsets.ts
+++ b/src/vs/workbench/api/common/extHostCodeInsets.ts
@@ -11,6 +11,7 @@ import { ExtHostEditors } from 'vs/workbench/api/common/extHostTextEditors';
 import * as vscode from 'vscode';
 import { ExtHostEditorInsetsShape, MainThreadEditorInsetsShape } from './extHost.protocol';
 import { toWebviewResource, WebviewInitData } from 'vs/workbench/api/common/shared/webview';
+import { generateUuid } from 'vs/base/common/uuid';
 
 export class ExtHostEditorInsets implements ExtHostEditorInsetsShape {
 
@@ -60,11 +61,12 @@ export class ExtHostEditorInsets implements ExtHostEditorInsetsShape {
 
 		const webview = new class implements vscode.Webview {
 
+			private readonly _uuid = generateUuid();
 			private _html: string = '';
 			private _options: vscode.WebviewOptions;
 
 			toWebviewResource(resource: vscode.Uri): vscode.Uri {
-				return toWebviewResource(that._initData, resource);
+				return toWebviewResource(that._initData, this._uuid, resource);
 			}
 
 			get cspRule(): string {
diff --git a/src/vs/workbench/api/common/extHostWebview.ts b/src/vs/workbench/api/common/extHostWebview.ts
index e4e4756afe9be75b410ffeefdd2500331ad536a4..5341db7fec5cf10025b973e97f63e5be1552aa32 100644
--- a/src/vs/workbench/api/common/extHostWebview.ts
+++ b/src/vs/workbench/api/common/extHostWebview.ts
@@ -13,40 +13,36 @@ import { Disposable } from './extHostTypes';
 import { IExtensionDescription } from 'vs/platform/extensions/common/extensions';
 import * as modes from 'vs/editor/common/modes';
 import { WebviewInitData, toWebviewResource } from 'vs/workbench/api/common/shared/webview';
+import { generateUuid } from 'vs/base/common/uuid';
 
 type IconPath = URI | { light: URI, dark: URI };
 
 export class ExtHostWebview implements vscode.Webview {
-	private readonly _handle: WebviewPanelHandle;
-	private readonly _proxy: MainThreadWebviewsShape;
+	private readonly _uuid: string = generateUuid();
+
 	private _html: string;
-	private _options: vscode.WebviewOptions;
 	private _isDisposed: boolean = false;
 
 	public readonly _onMessageEmitter = new Emitter<any>();
 	public readonly onDidReceiveMessage: Event<any> = this._onMessageEmitter.event;
 
 	constructor(
-		handle: WebviewPanelHandle,
-		proxy: MainThreadWebviewsShape,
-		options: vscode.WebviewOptions,
-		private readonly initData: WebviewInitData
-	) {
-		this._handle = handle;
-		this._proxy = proxy;
-		this._options = options;
-	}
+		private readonly _handle: WebviewPanelHandle,
+		private readonly _proxy: MainThreadWebviewsShape,
+		private _options: vscode.WebviewOptions,
+		private readonly _initData: WebviewInitData
+	) { }
 
 	public dispose() {
 		this._onMessageEmitter.dispose();
 	}
 
 	public toWebviewResource(resource: vscode.Uri): vscode.Uri {
-		return toWebviewResource(this.initData, resource);
+		return toWebviewResource(this._initData, this._uuid, resource);
 	}
 
 	public get cspRule(): string {
-		return this.initData.webviewCspRule;
+		return this._initData.webviewCspRule;
 	}
 
 	public get html(): string {
diff --git a/src/vs/workbench/api/common/shared/webview.ts b/src/vs/workbench/api/common/shared/webview.ts
index 95320c72136dfd9cac414224d5251d9099005e0c..798f685c762370c551ebeb2403f3d4cfe43a6920 100644
--- a/src/vs/workbench/api/common/shared/webview.ts
+++ b/src/vs/workbench/api/common/shared/webview.ts
@@ -13,12 +13,12 @@ export interface WebviewInitData {
 
 export function toWebviewResource(
 	initData: WebviewInitData,
+	uuid: string,
 	resource: vscode.Uri
 ): vscode.Uri {
-	const rootUri = URI.parse(initData.webviewResourceRoot);
-	return rootUri.with({
-		path: rootUri.path + resource.path,
-		query: resource.query,
-		fragment: resource.fragment,
-	});
+	const uri = initData.webviewResourceRoot
+		.replace('{{resource}}', resource.toString().replace(/^\S+?:/, ''))
+		.replace('{{uuid}}', uuid);
+
+	return URI.parse(uri);
 }
diff --git a/src/vs/workbench/services/environment/browser/environmentService.ts b/src/vs/workbench/services/environment/browser/environmentService.ts
index 947b0db9f590885fb1f6528b629d95c7f21e4598..ebb6a82e8bfb147ea4b44eac14877cf988ebb528 100644
--- a/src/vs/workbench/services/environment/browser/environmentService.ts
+++ b/src/vs/workbench/services/environment/browser/environmentService.ts
@@ -147,7 +147,7 @@ export class BrowserWorkbenchEnvironmentService implements IEnvironmentService {
 	webviewEndpoint?: string;
 
 	get webviewResourceRoot(): string {
-		return this.webviewEndpoint ? this.webviewEndpoint + '/vscode-resource' : 'vscode-resource:';
+		return this.webviewEndpoint ? this.webviewEndpoint + '/vscode-resource{{resource}}' : 'vscode-resource:{{resource}}';
 	}
 
 	get webviewCspRule(): string {
diff --git a/src/vs/workbench/test/electron-browser/api/extHostWebview.test.ts b/src/vs/workbench/test/electron-browser/api/extHostWebview.test.ts
index 5ea5164c7a16b562254c9f73436c243813181128..b36e94a31031063cdaafb07873aba30afabcbf1e 100644
--- a/src/vs/workbench/test/electron-browser/api/extHostWebview.test.ts
+++ b/src/vs/workbench/test/electron-browser/api/extHostWebview.test.ts
@@ -50,7 +50,10 @@ suite('ExtHostWebview', () => {
 
 	test('toWebviewResource for desktop vscode-resource scheme', () => {
 		const shape = createNoopMainThreadWebviews();
-		const extHostWebviews = new ExtHostWebviews(SingleProxyRPCProtocol(shape), { webviewCspRule: '', webviewResourceRoot: 'vscode-resource:' });
+		const extHostWebviews = new ExtHostWebviews(SingleProxyRPCProtocol(shape), {
+			webviewCspRule: '',
+			webviewResourceRoot: 'vscode-resource:{{resource}}'
+		});
 		const webview = extHostWebviews.createWebviewPanel({} as any, 'type', 'title', 1, {});
 
 		assert.strictEqual(
@@ -58,6 +61,7 @@ suite('ExtHostWebview', () => {
 			'vscode-resource:/Users/codey/file.html',
 			'Unix basic'
 		);
+
 		assert.strictEqual(
 			webview.webview.toWebviewResource(URI.parse('file:///Users/codey/file.html#frag')).toString(),
 			'vscode-resource:/Users/codey/file.html#frag',
@@ -70,12 +74,11 @@ suite('ExtHostWebview', () => {
 			'Unix with encoding'
 		);
 
-		// TODO: Fix for #48403
-		// assert.strictEqual(
-		// 	webview.webview.toWebviewResource(URI.parse('file://localhost/Users/codey/file.html')).toString(),
-		// 	'vscode-resource:/Users/codey/file.html',
-		// 	'Unix should preserve authority'
-		// );
+		assert.strictEqual(
+			webview.webview.toWebviewResource(URI.parse('file://localhost/Users/codey/file.html')).toString(),
+			'vscode-resource://localhost/Users/codey/file.html',
+			'Unix should preserve authority'
+		);
 
 		assert.strictEqual(
 			webview.webview.toWebviewResource(URI.parse('file:///c:/codey/file.txt')).toString(),
@@ -83,6 +86,50 @@ suite('ExtHostWebview', () => {
 			'Windows C drive'
 		);
 	});
+
+	test('toWebviewResource for web endpoint', () => {
+		const shape = createNoopMainThreadWebviews();
+
+		const extHostWebviews = new ExtHostWebviews(SingleProxyRPCProtocol(shape), {
+			webviewCspRule: '',
+			webviewResourceRoot: `https://{{uuid}}.webview.contoso.com/commit{{resource}}`
+		});
+		const webview = extHostWebviews.createWebviewPanel({} as any, 'type', 'title', 1, {});
+
+		function stripEndpointUuid(input: string) {
+			return input.replace(/^https:\/\/[^\.]+?\./, '');
+		}
+
+		assert.strictEqual(
+			stripEndpointUuid(webview.webview.toWebviewResource(URI.parse('file:///Users/codey/file.html')).toString()),
+			'webview.contoso.com/commit///Users/codey/file.html',
+			'Unix basic'
+		);
+
+		assert.strictEqual(
+			stripEndpointUuid(webview.webview.toWebviewResource(URI.parse('file:///Users/codey/file.html#frag')).toString()),
+			'webview.contoso.com/commit///Users/codey/file.html#frag',
+			'Unix should preserve fragment'
+		);
+
+		assert.strictEqual(
+			stripEndpointUuid(webview.webview.toWebviewResource(URI.parse('file:///Users/codey/f%20ile.html')).toString()),
+			'webview.contoso.com/commit///Users/codey/f%20ile.html',
+			'Unix with encoding'
+		);
+
+		assert.strictEqual(
+			stripEndpointUuid(webview.webview.toWebviewResource(URI.parse('file://localhost/Users/codey/file.html')).toString()),
+			'webview.contoso.com/commit//localhost/Users/codey/file.html',
+			'Unix should preserve authority'
+		);
+
+		assert.strictEqual(
+			stripEndpointUuid(webview.webview.toWebviewResource(URI.parse('file:///c:/codey/file.txt')).toString()),
+			'webview.contoso.com/commit///c%3A/codey/file.txt',
+			'Windows C drive'
+		);
+	});
 });