diff --git a/packages/trace-viewer/src/ui/modelUtil.ts b/packages/trace-viewer/src/ui/modelUtil.ts
index 6385f577c8ed8..ba866ad7caf29 100644
--- a/packages/trace-viewer/src/ui/modelUtil.ts
+++ b/packages/trace-viewer/src/ui/modelUtil.ts
@@ -157,6 +157,8 @@ function indexModel(context: ContextEntry) {
   }
   for (const event of context.events)
     (event as any)[contextSymbol] = context;
+  for (const resource of context.resources)
+    (resource as any)[contextSymbol] = context;
 }
 
 function mergeActionsAndUpdateTiming(contexts: ContextEntry[]) {
@@ -330,7 +332,7 @@ export function idForAction(action: ActionTraceEvent) {
   return `${action.pageId || 'none'}:${action.callId}`;
 }
 
-export function context(action: ActionTraceEvent | trace.EventTraceEvent): ContextEntry {
+export function context(action: ActionTraceEvent | trace.EventTraceEvent | ResourceSnapshot): ContextEntry {
   return (action as any)[contextSymbol];
 }
 
diff --git a/packages/trace-viewer/src/ui/networkTab.tsx b/packages/trace-viewer/src/ui/networkTab.tsx
index b3caa501b5768..7172a5eabdbea 100644
--- a/packages/trace-viewer/src/ui/networkTab.tsx
+++ b/packages/trace-viewer/src/ui/networkTab.tsx
@@ -21,7 +21,7 @@ import './networkTab.css';
 import { NetworkResourceDetails } from './networkResourceDetails';
 import { bytesToString, msToString } from '@web/uiUtils';
 import { PlaceholderPanel } from './placeholderPanel';
-import type { MultiTraceModel } from './modelUtil';
+import { context, type MultiTraceModel } from './modelUtil';
 import { GridView, type RenderedGridCell } from '@web/components/gridView';
 import { SplitView } from '@web/components/splitView';
 
@@ -39,6 +39,7 @@ type RenderedEntry = {
   start: number,
   route: string,
   resource: Entry,
+  contextId: string,
 };
 type ColumnName = keyof RenderedEntry;
 type Sorting = { by: ColumnName, negate: boolean};
@@ -60,13 +61,15 @@ export function useNetworkTabModel(model: MultiTraceModel | undefined, selectedT
 export const NetworkTab: React.FunctionComponent<{
   boundaries: Boundaries,
   networkModel: NetworkTabModel,
+  model?: MultiTraceModel,
   onEntryHovered: (entry: Entry | undefined) => void,
-}> = ({ boundaries, networkModel, onEntryHovered }) => {
+}> = ({ boundaries, networkModel, model, onEntryHovered }) => {
   const [sorting, setSorting] = React.useState<Sorting | undefined>(undefined);
   const [selectedEntry, setSelectedEntry] = React.useState<RenderedEntry | undefined>(undefined);
 
   const { renderedEntries } = React.useMemo(() => {
-    const renderedEntries = networkModel.resources.map(entry => renderEntry(entry, boundaries));
+    const generator = ContextIdGenerator.forModel(model);
+    const renderedEntries = networkModel.resources.map(entry => renderEntry(entry, boundaries, generator));
     if (sorting)
       sort(renderedEntries, sorting);
     return { renderedEntries };
@@ -81,7 +84,7 @@ export const NetworkTab: React.FunctionComponent<{
     selectedItem={selectedEntry}
     onSelected={item => setSelectedEntry(item)}
     onHighlighted={item => onEntryHovered(item?.resource)}
-    columns={selectedEntry ? ['name'] : ['name', 'method', 'status', 'contentType', 'duration', 'size', 'start', 'route']}
+    columns={visibleColumns(!!selectedEntry, renderedEntries)}
     columnTitle={columnTitle}
     columnWidth={columnWidth}
     isError={item => item.status.code >= 400}
@@ -100,6 +103,8 @@ export const NetworkTab: React.FunctionComponent<{
 };
 
 const columnTitle = (column: ColumnName) => {
+  if (column === 'contextId')
+    return 'Source';
   if (column === 'name')
     return 'Name';
   if (column === 'method')
@@ -131,7 +136,23 @@ const columnWidth = (column: ColumnName) => {
   return 100;
 };
 
+function visibleColumns(entrySelected: boolean, renderedEntries: RenderedEntry[]): (keyof RenderedEntry)[] {
+  if (entrySelected)
+    return ['name'];
+  const columns: (keyof RenderedEntry)[] = [];
+  if (hasMultipleContexts(renderedEntries))
+    columns.push('contextId');
+  columns.push('name', 'method', 'status', 'contentType', 'duration', 'size', 'start', 'route');
+  return columns;
+}
+
 const renderCell = (entry: RenderedEntry, column: ColumnName): RenderedGridCell => {
+  if (column === 'contextId') {
+    return {
+      body: entry.contextId,
+      title: entry.name.url,
+    };
+  }
   if (column === 'name') {
     return {
       body: entry.name.name,
@@ -159,7 +180,67 @@ const renderCell = (entry: RenderedEntry, column: ColumnName): RenderedGridCell
   return { body: '' };
 };
 
-const renderEntry = (resource: Entry, boundaries: Boundaries): RenderedEntry => {
+class ContextIdGenerator {
+  private _pagerefToShortId = new Map<string, string>();
+  private _lastPageId = 0;
+  private _lastApiRequestContextId = 0;
+  private static _apiRequestContextIdSymbol = Symbol('apiRequestContextId');
+  private static _contextIdGeneratorSymbol = Symbol('contextIdGenerator');
+
+  static forModel(model?: MultiTraceModel): ContextIdGenerator {
+    if (!model)
+      return new ContextIdGenerator();
+    let generator = (model as any)[ContextIdGenerator._contextIdGeneratorSymbol];
+    if (!generator) {
+      generator = new ContextIdGenerator();
+      (model as any)[ContextIdGenerator._contextIdGeneratorSymbol] = generator;
+    }
+    return generator;
+  }
+
+  contextId(resource: Entry): string {
+    if (resource.pageref)
+      return this._pageId(resource.pageref);
+    else if (resource._apiRequest)
+      return this._apiRequestContextId(resource);
+    return '';
+  }
+
+  private _pageId(pageref: string): string {
+    let shortId = this._pagerefToShortId.get(pageref);
+    if (!shortId) {
+      ++this._lastPageId;
+      shortId = 'page@' + this._lastPageId;
+      this._pagerefToShortId.set(pageref, shortId);
+    }
+    return shortId;
+  }
+
+  private _apiRequestContextId(resource: Entry): string {
+    const contextEntry = context(resource);
+    if (!contextEntry)
+      return '';
+    let contextId = (contextEntry as any)[ContextIdGenerator._apiRequestContextIdSymbol];
+    if (!contextId) {
+      ++this._lastApiRequestContextId;
+      contextId = 'api@' + this._lastApiRequestContextId;
+      (contextEntry as any)[ContextIdGenerator._apiRequestContextIdSymbol] = contextId;
+    }
+    return contextId;
+  }
+}
+
+function hasMultipleContexts(renderedEntries: RenderedEntry[]): boolean {
+  const contextIds = new Set<string>();
+  for (const entry of renderedEntries) {
+    contextIds.add(entry.contextId);
+    if (contextIds.size > 1)
+      return true;
+  }
+  return false;
+}
+
+const renderEntry = (resource: Entry, boundaries: Boundaries, contextIdGenerator: ContextIdGenerator): RenderedEntry => {
   const routeStatus = formatRouteStatus(resource);
   let resourceName: string;
   try {
@@ -184,7 +265,8 @@ const renderEntry = (resource: Entry, boundaries: Boundaries): RenderedEntry =>
     size: resource.response._transferSize! > 0 ? resource.response._transferSize! : resource.response.bodySize,
     start: resource._monotonicTime! - boundaries.minimum,
     route: routeStatus,
-    resource
+    resource,
+    contextId: contextIdGenerator.contextId(resource),
   };
 };
 
@@ -249,4 +331,7 @@ function comparator(sortBy: ColumnName) {
       return a.route.localeCompare(b.route);
     };
   }
+
+  if (sortBy === 'contextId')
+    return (a: RenderedEntry, b: RenderedEntry) => a.contextId.localeCompare(b.contextId);
 }
diff --git a/packages/trace-viewer/src/ui/workbench.tsx b/packages/trace-viewer/src/ui/workbench.tsx
index c50b345b75f22..17c63ad8704f3 100644
--- a/packages/trace-viewer/src/ui/workbench.tsx
+++ b/packages/trace-viewer/src/ui/workbench.tsx
@@ -172,7 +172,7 @@ export const Workbench: React.FunctionComponent<{
     id: 'network',
     title: 'Network',
     count: networkModel.resources.length,
-    render: () => <NetworkTab boundaries={boundaries} networkModel={networkModel} onEntryHovered={setHighlightedEntry}/>
+    render: () => <NetworkTab boundaries={boundaries} networkModel={networkModel} model={model} onEntryHovered={setHighlightedEntry}/>
   };
   const attachmentsTab: TabbedPaneTabModel = {
     id: 'attachments',
diff --git a/tests/playwright-test/ui-mode-trace.spec.ts b/tests/playwright-test/ui-mode-trace.spec.ts
index 194e89afba598..c9afe336e6c66 100644
--- a/tests/playwright-test/ui-mode-trace.spec.ts
+++ b/tests/playwright-test/ui-mode-trace.spec.ts
@@ -285,3 +285,24 @@ test('should reveal errors in the sourcetab', async ({ runUITest }) => {
   await page.getByText('a.spec.ts:4', { exact: true }).click();
   await expect(page.locator('.source-line-running')).toContainText(`throw new Error('Oh my');`);
 });
+
+test('should show request source context id', async ({ runUITest, server }) => {
+  const { page } = await runUITest({
+    'a.spec.ts': `
+      import { test, expect } from '@playwright/test';
+      test('pass', async ({ page, context, request }) => {
+        await page.goto('${server.EMPTY_PAGE}');
+        const page2 = await context.newPage();
+        await page2.goto('${server.EMPTY_PAGE}');
+        await request.get('${server.EMPTY_PAGE}');
+      });
+    `,
+  });
+
+  await page.getByText('pass').dblclick();
+  await page.getByText('Network', { exact: true }).click();
+  await expect(page.locator('span').filter({ hasText: 'Source' })).toBeVisible();
+  await expect(page.getByText('page@1')).toBeVisible();
+  await expect(page.getByText('page@2')).toBeVisible();
+  await expect(page.getByText('api@1')).toBeVisible();
+});