diff --git a/packages/trace-viewer/src/ui/networkTab.tsx b/packages/trace-viewer/src/ui/networkTab.tsx
index b86da754a3..2448c3c0bc 100644
--- a/packages/trace-viewer/src/ui/networkTab.tsx
+++ b/packages/trace-viewer/src/ui/networkTab.tsx
@@ -133,6 +133,8 @@ const columnWidth = (column: ColumnName) => {
     return 60;
   if (column === 'contentType')
     return 200;
+  if (column === 'contextId')
+    return 60;
   return 100;
 };
 
@@ -210,7 +212,7 @@ class ContextIdGenerator {
     let shortId = this._pagerefToShortId.get(pageref);
     if (!shortId) {
       ++this._lastPageId;
-      shortId = 'page@' + this._lastPageId;
+      shortId = 'page#' + this._lastPageId;
       this._pagerefToShortId.set(pageref, shortId);
     }
     return shortId;
@@ -223,7 +225,7 @@ class ContextIdGenerator {
     let contextId = (contextEntry as any)[ContextIdGenerator._apiRequestContextIdSymbol];
     if (!contextId) {
       ++this._lastApiRequestContextId;
-      contextId = 'api@' + this._lastApiRequestContextId;
+      contextId = 'api#' + this._lastApiRequestContextId;
       (contextEntry as any)[ContextIdGenerator._apiRequestContextIdSymbol] = contextId;
     }
     return contextId;
diff --git a/tests/playwright-test/ui-mode-trace.spec.ts b/tests/playwright-test/ui-mode-trace.spec.ts
index c9afe336e6..0f6194b25f 100644
--- a/tests/playwright-test/ui-mode-trace.spec.ts
+++ b/tests/playwright-test/ui-mode-trace.spec.ts
@@ -302,7 +302,7 @@ test('should show request source context id', async ({ runUITest, server }) => {
   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();
+  await expect(page.getByText('page#1')).toBeVisible();
+  await expect(page.getByText('page#2')).toBeVisible();
+  await expect(page.getByText('api#1')).toBeVisible();
 });