diff --git a/src/cli/traceViewer/web/ui/actionList.css b/src/cli/traceViewer/web/ui/actionList.css
index 970180556a..c58cb701d0 100644
--- a/src/cli/traceViewer/web/ui/actionList.css
+++ b/src/cli/traceViewer/web/ui/actionList.css
@@ -66,6 +66,13 @@
   white-space: nowrap;
 }
 
+.action-header .action-error {
+  color: red;
+  top: 2px;
+  position: relative;
+  margin-right: 2px;
+}
+
 .action-selector {
   display: inline;
   padding-left: 5px;
diff --git a/src/cli/traceViewer/web/ui/actionList.tsx b/src/cli/traceViewer/web/ui/actionList.tsx
index 94b38c4542..283c758d26 100644
--- a/src/cli/traceViewer/web/ui/actionList.tsx
+++ b/src/cli/traceViewer/web/ui/actionList.tsx
@@ -20,16 +20,23 @@ import * as React from 'react';
 
 export const ActionList: React.FunctionComponent<{
   actions: ActionEntry[],
-  selectedAction?: ActionEntry,
+  selectedAction: ActionEntry | undefined,
+  highlightedAction: ActionEntry | undefined,
   onSelected: (action: ActionEntry) => void,
-}> = ({ actions, selectedAction, onSelected }) => {
+  onHighlighted: (action: ActionEntry | undefined) => void,
+}> = ({ actions, selectedAction, highlightedAction, onSelected, onHighlighted }) => {
+  const targetAction = highlightedAction || selectedAction;
   return <div className='action-list'>{actions.map(actionEntry => {
     const { action, actionId } = actionEntry;
     return <div
-      className={'action-entry' + (actionEntry === selectedAction ? ' selected' : '')}
+      className={'action-entry' + (actionEntry === targetAction ? ' selected' : '')}
       key={actionId}
-      onClick={() => onSelected(actionEntry)}>
+      onClick={() => onSelected(actionEntry)}
+      onMouseEnter={() => onHighlighted(actionEntry)}
+      onMouseLeave={() => (highlightedAction === actionEntry) && onHighlighted(undefined)}
+      >
       <div className='action-header'>
+        <div className={'action-error codicon codicon-issues'} hidden={!actionEntry.action.error} />
         <div className='action-title'>{action.action}</div>
         {action.selector && <div className='action-selector' title={action.selector}>{action.selector}</div>}
         {action.action === 'goto' && action.value && <div className='action-url' title={action.value}>{action.value}</div>}
diff --git a/src/cli/traceViewer/web/ui/logsTab.css b/src/cli/traceViewer/web/ui/logsTab.css
new file mode 100644
index 0000000000..b177874fd5
--- /dev/null
+++ b/src/cli/traceViewer/web/ui/logsTab.css
@@ -0,0 +1,29 @@
+/*
+  Copyright (c) Microsoft Corporation.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+      http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+*/
+
+.logs-tab {
+  flex: auto;
+  position: relative;
+  overflow: auto;
+  background: #fdfcfc;
+  font-family: var(--monospace-font);
+  white-space: nowrap;
+}
+
+.log-line {
+  margin: 0 10px;
+  white-space: pre;
+}
diff --git a/src/cli/traceViewer/web/ui/logsTab.tsx b/src/cli/traceViewer/web/ui/logsTab.tsx
new file mode 100644
index 0000000000..2385d810b5
--- /dev/null
+++ b/src/cli/traceViewer/web/ui/logsTab.tsx
@@ -0,0 +1,37 @@
+/**
+ * Copyright (c) Microsoft Corporation.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { ActionEntry } from '../../traceModel';
+import * as React from 'react';
+import './logsTab.css';
+
+export const LogsTab: React.FunctionComponent<{
+  actionEntry: ActionEntry | undefined,
+}> = ({ actionEntry }) => {
+  let logs: string[] = [];
+  if (actionEntry) {
+    logs = actionEntry.action.logs || [];
+    if (actionEntry.action.error)
+      logs = [actionEntry.action.error, ...logs];
+  }
+  return <div className='logs-tab'>{
+    logs.map((logLine, index) => {
+      return <div key={index} className='log-line'>
+        {logLine}
+      </div>;
+    })
+  }</div>;
+};
diff --git a/src/cli/traceViewer/web/ui/propertiesTabbedPane.tsx b/src/cli/traceViewer/web/ui/propertiesTabbedPane.tsx
index be3305b65a..8df868c964 100644
--- a/src/cli/traceViewer/web/ui/propertiesTabbedPane.tsx
+++ b/src/cli/traceViewer/web/ui/propertiesTabbedPane.tsx
@@ -21,12 +21,13 @@ import { SourceTab } from './sourceTab';
 import './propertiesTabbedPane.css';
 import * as React from 'react';
 import { useMeasure } from './helpers';
+import { LogsTab } from './logsTab';
 
 export const PropertiesTabbedPane: React.FunctionComponent<{
   actionEntry: ActionEntry | undefined,
   snapshotSize: Size,
 }> = ({ actionEntry, snapshotSize }) => {
-  const [selected, setSelected] = React.useState<'snapshot' | 'source' | 'network'>('snapshot');
+  const [selected, setSelected] = React.useState<'snapshot' | 'source' | 'network' | 'logs'>('snapshot');
   return <div className='properties-tabbed-pane'>
     <div className='vbox'>
       <div className='hbox' style={{ flex: 'none' }}>
@@ -43,6 +44,10 @@ export const PropertiesTabbedPane: React.FunctionComponent<{
             onClick={() => setSelected('network')}>
             <div className='properties-tab-label'>Network</div>
           </div>
+          <div className={'properties-tab-element ' + (selected === 'logs' ? 'selected' : '')}
+            onClick={() => setSelected('logs')}>
+            <div className='properties-tab-label'>Logs</div>
+          </div>
         </div>
       </div>
       <div className='properties-tab-content' style={{ display: selected === 'snapshot' ? 'flex' : 'none' }}>
@@ -54,6 +59,9 @@ export const PropertiesTabbedPane: React.FunctionComponent<{
       <div className='properties-tab-content' style={{ display: selected === 'network' ? 'flex' : 'none' }}>
         <NetworkTab actionEntry={actionEntry} />
       </div>
+      <div className='properties-tab-content' style={{ display: selected === 'logs' ? 'flex' : 'none' }}>
+        <LogsTab actionEntry={actionEntry} />
+      </div>
     </div>
   </div>;
 };
diff --git a/src/cli/traceViewer/web/ui/timeline.css b/src/cli/traceViewer/web/ui/timeline.css
index 24fa5b057b..497f0a2675 100644
--- a/src/cli/traceViewer/web/ui/timeline.css
+++ b/src/cli/traceViewer/web/ui/timeline.css
@@ -64,6 +64,7 @@
 
 .timeline-lane.timeline-actions {
   margin-bottom: 10px;
+  overflow: visible;
 }
 
 .timeline-action {
@@ -72,19 +73,26 @@
   bottom: 0;
   background-color: red;
   border-radius: 3px;
+  --action-color: 'transparent';
+  background-color: var(--action-color);
+}
+
+.timeline-action.selected {
+  filter: brightness(70%);
+  box-shadow: 0 0 0 1px var(--action-color);
 }
 
 .timeline-action.click {
-  background-color: var(--green);
+  --action-color: var(--green);
 }
 
 .timeline-action.fill,
 .timeline-action.press {
-  background-color: var(--orange);
+  --action-color: var(--orange);
 }
 
 .timeline-action.goto {
-  background-color: var(--blue);
+  --action-color: var(--blue);
 }
 
 .timeline-action-label {
@@ -93,6 +101,12 @@
   bottom: 0;
   margin-left: 2px;
   background-color: #fffffff0;
+  justify-content: center;
+  display: none;
+}
+
+.timeline-action-label.selected {
+  display: flex;
 }
 
 .timeline-time-bar {
diff --git a/src/cli/traceViewer/web/ui/timeline.tsx b/src/cli/traceViewer/web/ui/timeline.tsx
index 25e48452f5..676834fa3c 100644
--- a/src/cli/traceViewer/web/ui/timeline.tsx
+++ b/src/cli/traceViewer/web/ui/timeline.tsx
@@ -21,19 +21,25 @@ import { FilmStrip } from './filmStrip';
 import { Boundaries } from '../geometry';
 import * as React from 'react';
 import { useMeasure } from './helpers';
+import { ActionEntry } from '../../traceModel';
 
 export const Timeline: React.FunctionComponent<{
   context: ContextEntry,
   boundaries: Boundaries,
-}> = ({ context, boundaries }) => {
+  selectedAction: ActionEntry | undefined,
+  highlightedAction: ActionEntry | undefined,
+  onSelected: (action: ActionEntry) => void,
+  onHighlighted: (action: ActionEntry | undefined) => void,
+}> = ({ context, boundaries, selectedAction, highlightedAction, onSelected, onHighlighted }) => {
   const [measure, ref] = useMeasure<HTMLDivElement>();
   const [previewX, setPreviewX] = React.useState<number | undefined>();
+  const targetAction = highlightedAction || selectedAction;
 
   const offsets = React.useMemo(() => {
     return calculateDividerOffsets(measure.width, boundaries);
   }, [measure.width, boundaries]);
   const actionEntries = React.useMemo(() => {
-    const actions = [];
+    const actions: ActionEntry[] = [];
     for (const page of context.pages)
       actions.push(...page.actions);
     return actions;
@@ -41,23 +47,52 @@ export const Timeline: React.FunctionComponent<{
   const actionTimes = React.useMemo(() => {
     return actionEntries.map(entry => {
       return {
-        action: entry.action,
-        actionId: entry.actionId,
+        entry,
         left: timeToPercent(measure.width, boundaries, entry.action.startTime!),
         right: timeToPercent(measure.width, boundaries, entry.action.endTime!),
       };
     });
   }, [actionEntries, boundaries, measure.width]);
 
+  const findHoveredAction = (x: number) => {
+    const time = positionToTime(measure.width, boundaries, x);
+    const time1 = positionToTime(measure.width, boundaries, x - 5);
+    const time2 = positionToTime(measure.width, boundaries, x + 5);
+    let entry: ActionEntry | undefined;
+    let distance: number | undefined;
+    for (const e of actionEntries) {
+      const left = Math.max(e.action.startTime!, time1);
+      const right = Math.min(e.action.endTime!, time2);
+      const middle = (e.action.startTime! + e.action.endTime!) / 2;
+      const d = Math.abs(time - middle);
+      if (left <= right && (!entry || d < distance!)) {
+        entry = e;
+        distance = d;
+      }
+    }
+    return entry;
+  };
+
   const onMouseMove = (event: React.MouseEvent) => {
-    if (ref.current)
-      setPreviewX(event.clientX - ref.current.getBoundingClientRect().left);
+    if (ref.current) {
+      const x = event.clientX - ref.current.getBoundingClientRect().left;
+      setPreviewX(x);
+      onHighlighted(findHoveredAction(x));
+    }
   };
   const onMouseLeave = () => {
     setPreviewX(undefined);
   };
+  const onClick = (event: React.MouseEvent) => {
+    if (ref.current) {
+      const x = event.clientX - ref.current.getBoundingClientRect().left;
+      const entry = findHoveredAction(x);
+      if (entry)
+        onSelected(entry);
+    }
+  };
 
-  return <div ref={ref} className='timeline-view' onMouseMove={onMouseMove} onMouseOver={onMouseMove} onMouseLeave={onMouseLeave}>
+  return <div ref={ref} className='timeline-view' onMouseMove={onMouseMove} onMouseOver={onMouseMove} onMouseLeave={onMouseLeave} onClick={onClick}>
     <div className='timeline-grid'>{
       offsets.map((offset, index) => {
         return <div key={index} className='timeline-divider' style={{ left: offset.percent + '%' }}>
@@ -66,19 +101,22 @@ export const Timeline: React.FunctionComponent<{
       })
     }</div>
     <div className='timeline-lane timeline-action-labels'>{
-      actionTimes.map(({ action, actionId, left }) => {
-        return <div key={actionId}
-          className={'timeline-action-label ' + action.action}
-          style={{ left: left + '%' }}
+      actionTimes.map(({ entry, left, right }) => {
+        return <div key={entry.actionId}
+          className={'timeline-action-label ' + entry.action.action + (targetAction === entry ? ' selected' : '')}
+          style={{
+            left: left + '%',
+            width: (right - left) + '%',
+          }}
         >
-          {action.action}
+          {entry.action.action}
         </div>;
       })
     }</div>
     <div className='timeline-lane timeline-actions'>{
-      actionTimes.map(({ action, actionId, left, right }) => {
-        return <div key={actionId}
-          className={'timeline-action ' + action.action}
+      actionTimes.map(({ entry, left, right }) => {
+        return <div key={entry.actionId}
+          className={'timeline-action ' + entry.action.action + (targetAction === entry ? ' selected' : '')}
           style={{
             left: left + '%',
             width: (right - left) + '%',
@@ -129,6 +167,11 @@ function timeToPercent(clientWidth: number, boundaries: Boundaries, time: number
   return 100 * position / clientWidth;
 }
 
+function positionToTime(clientWidth: number, boundaries: Boundaries, x: number): number {
+  const percent = x / clientWidth;
+  return percent * (boundaries.maximum - boundaries.minimum) + boundaries.minimum;
+}
+
 function msToString(ms: number): string {
   if (!isFinite(ms))
     return '-';
diff --git a/src/cli/traceViewer/web/ui/workbench.tsx b/src/cli/traceViewer/web/ui/workbench.tsx
index 1aeb33be9a..c6a1cae45c 100644
--- a/src/cli/traceViewer/web/ui/workbench.tsx
+++ b/src/cli/traceViewer/web/ui/workbench.tsx
@@ -26,7 +26,8 @@ export const Workbench: React.FunctionComponent<{
   traceModel: TraceModel,
 }> = ({ traceModel }) => {
   const [context, setContext] = React.useState(traceModel.contexts[0]);
-  const [action, setAction] = React.useState<ActionEntry | undefined>();
+  const [selectedAction, setSelectedAction] = React.useState<ActionEntry | undefined>();
+  const [highlightedAction, setHighlightedAction] = React.useState<ActionEntry | undefined>();
 
   const actions = React.useMemo(() => {
     const actions: ActionEntry[] = [];
@@ -47,7 +48,7 @@ export const Workbench: React.FunctionComponent<{
         context={context}
         onChange={context => {
           setContext(context);
-          setAction(undefined);
+          setSelectedAction(undefined);
         }}
       />
     </div>
@@ -55,13 +56,23 @@ export const Workbench: React.FunctionComponent<{
       <Timeline
         context={context}
         boundaries={{ minimum: context.startTime, maximum: context.endTime }}
-      />
+        selectedAction={selectedAction}
+        highlightedAction={highlightedAction}
+        onSelected={action => setSelectedAction(action)}
+        onHighlighted={action => setHighlightedAction(action)}
+        />
     </div>
     <div className='hbox'>
       <div style={{ display: 'flex', flex: 'none' }}>
-        <ActionList actions={actions} selectedAction={action} onSelected={action => setAction(action)} />
+        <ActionList
+          actions={actions}
+          selectedAction={selectedAction}
+          highlightedAction={highlightedAction}
+          onSelected={action => setSelectedAction(action)}
+          onHighlighted={action => setHighlightedAction(action)}
+        />
       </div>
-      <PropertiesTabbedPane actionEntry={action} snapshotSize={snapshotSize} />
+      <PropertiesTabbedPane actionEntry={selectedAction} snapshotSize={snapshotSize} />
     </div>
   </div>;
 };
diff --git a/src/cli/traceViewer/web/web.webpack.config.js b/src/cli/traceViewer/web/web.webpack.config.js
index 4fd608469e..dedec1cf60 100644
--- a/src/cli/traceViewer/web/web.webpack.config.js
+++ b/src/cli/traceViewer/web/web.webpack.config.js
@@ -2,7 +2,7 @@ const path = require('path');
 const HtmlWebPackPlugin = require('html-webpack-plugin');
 
 module.exports = {
-  mode: 'production',
+  mode: process.env.NODE_ENV === 'production' ? 'production' : 'development',
   entry: {
     app: path.join(__dirname, 'index.tsx'),
   },