You are three minutes into a live demo. A Slack message pops up from your manager. The notification is visible to everyone on the call. You dismiss it, keep going, and the moment is gone.

Another common occurrence: you share your screen and the client can see that you have 24 tabs open, a bookmarks bar full of personal folders, and your desktop background from a family holiday. You got the product working perfectly. The setup did not match.

Live demos fail for two kinds of reasons. The first is the product itself. The second is everything around it. The second category is entirely preventable.

This checklist covers the second category. It is not a theory of better demos. It is a concrete list of things to do before you share your screen.

Before you share your screen

Work through this list in order. The browser items take under two minutes. The system items take under five. Run it the same way before every demo and it becomes automatic.

Browser

Close all unrelated tabs. Every tab you have open is visible across the top of the browser during a screen share. Close anything that is not part of the demo flow. If you need reference material, use a second browser window that you are not sharing.

Reset browser zoom to 100%. Demo flows often span multiple tabs. Zoom levels accumulate across sessions. Press Cmd+0 on Mac or Ctrl+0 on Windows on each tab in your demo flow, or use a tool that resets all tabs at once before you start.

Hide the bookmarks bar. Press Cmd+Shift+B on Mac or Ctrl+Shift+B on Windows. The bookmarks bar is visible the entire time you are in a new tab or navigating. Personal folders, saved passwords, and browser history links do not belong in a client-facing screen share.

Dismiss any pending browser update banners. Chrome and other browsers surface update prompts in the top bar. These are visible on screen share and draw attention away from the product. Dismiss them before you start. Do not click to update mid-demo.

Pre-navigate to your starting page. Do not share your screen from your home page or a blank tab and then navigate live. Load the exact page you plan to open on. Share from there.

Notifications

Silence Slack and other chat apps. Turning off desktop notifications is not enough. Mute the tab in your browser if Slack runs in a tab. Turn off the desktop app notifications entirely. Do not rely on Do Not Focus mode or similar — app-level muting is more reliable.

Close email entirely. Do not just switch to another app. Quit your email client. Badge counts and preview panes are visible in your dock when you accidentally show the desktop. New mail previews can appear on screen without warning. Close it.

Turn off calendar notifications. Meeting reminders fire at the worst possible times. A “Joining in 5 minutes” popup during a demo closing is visible to everyone on the call. Turn off calendar notifications before every session.

Check video conference chat notification overlays. Zoom, Google Meet, and Teams all surface chat messages as overlays on your screen during a call. These overlay your screen share. Turn them off in the conferencing app settings before you present.

Set your phone to do not disturb. Your phone does not need to be visible for this to matter. If you share audio and your phone rings, the client hears it. If you are sharing a mobile screen, notifications are visible. Put it on do not disturb before every call.

Environment and accounts

Sign out of personal accounts. If you use a single browser profile for both personal and work browsing, your personal Google account, personal Notion workspace, or personal Dropbox may be visible in autofill suggestions and account pickers. Sign out of anything personal before the demo, or use a dedicated Chrome profile for demo work.

Verify the correct environment is loaded. Before sharing, confirm you are in the right tenant, the right sandbox, the right account. If you demo across multiple environments or personas, confirm explicitly rather than assuming. A staging environment showing test data to a prospect, or a client A environment visible during a client B walkthrough, is not an embarrassing mistake. It is a trust problem.

If you demo across multiple accounts or environments, consider DemoTag. DemoTag is a Chrome extension that labels every browser page with the active persona name and renames the tab to match. When you switch between an admin account and an end-user account, every tab tells you exactly where you are. It does not rely on you remembering. The label is always visible.

Showing the wrong environment to a client is not an embarrassing mistake. It is a trust problem. DemoTag removes the possibility of being in the wrong account without knowing it.

DemoTag is coming soon to the Chrome Web Store. Sign up to be notified.

Disable VPN if it adds a visible notification bar. Some VPN clients inject a bar or indicator at the top or bottom of the screen that is visible during a screen share. If your VPN does this, disconnect it before sharing — unless the demo requires it.

System

Clear or hide your desktop. If you accidentally exit the browser or a window closes, the client sees your desktop. A clean desktop takes ten seconds to set up. Move personal files off the desktop entirely, or use a temporary clean background.

Check which monitor is being shared if you use dual monitors. This is the most common dual-monitor mistake. Check your sharing settings in the conferencing tool before you start. Confirm which screen is being shared, not which screen you are looking at.

Check that OS screen recording permissions are granted. macOS requires explicit screen recording permissions for Zoom, Teams, and Meet. If you have updated your OS or installed a new conferencing tool recently, the permission may not be set. Check System Settings before the call, not during.

Check that iCloud, Dropbox, or Drive sync is not mid-upload. Sync clients running in the background consume bandwidth and occasionally surface visible upload status in the menu bar. If you have large files syncing, pause the sync client before you start.

Check battery and plug in to power. Low battery warnings appear on screen and can interrupt a presentation. Plug in before every demo. If you are presenting from a location without reliable power access, check battery level and plan accordingly.

Check microphone and camera before the call. Join an audio check or test call five minutes early. The conferencing tool you tested with last week may not have remained the default. Confirm your microphone input and camera are selected correctly before the client joins.

Why most SEs skip this

Every item on this list is something an experienced SE has already encountered. The problem is not knowledge. Most SEs know they should close email and check their audio. The problem is consistency.

A pre-demo checklist works because it moves these checks from memory to habit. You do not have to remember what to check. You run the list.

The SEs who look most prepared in front of clients are not the ones who improvise best. They are the ones who have fewer things go wrong.