Guide

How to audit your screen sharing for leaks

Screen sharing is the most common way people accidentally share private information. Every meeting, every demo, every tutorial is a chance to leak something that should stay private.

Here is how to audit your screen before you share it.

The Audit Framework

Before you click "Share Screen," run through this checklist. It takes less than a minute and it catches 90% of what gets missed.

1. Close Everything You Won't Use

This sounds obvious. It is not.

Before sharing, look at your dock, your open windows, and your notification area. Close anything that is not part of your presentation. That includes:

• The chat app you use with friends (Discord, WhatsApp, Slack)
• Your email client
• Any admin panels or dashboards
• Your personal calendar
• Notes apps with to-do lists
• Browser tabs with unrelated content

Every open window is a potential leak. If you are not showing it, close it.

2. Check Your Second Monitor

This is the big one. Most of the time your audience only sees the window you shared. But if you share your entire desktop or use a multi-monitor setup, they might see your second screen too.

Check:

• Are there open browser tabs with private content?
• Is there a .env file, a config file, or a terminal window with credentials?
• Is there an email open with sensitive content?
• Are there sticky notes or a notes app with passwords, codes, or reminders?

If you use a second monitor for your personal workflow, assume the audience can see it unless you explicitly share only the target window.

3. Look at Your Notification Settings

Notifications are the quietest leak. A calendar alert pops up mid-meeting. A new email arrives with a subject line that reveals too much. A text message shows a preview with content you did not intend to share.

Before your next meeting:

• Enable "Do Not Disturb" on your Mac
• Check that your notification preview does not show message content (System Settings > Notifications > Show Previews > When Unlocked or Never)
• Close any open message threads

Even a momentary notification can expose enough to be a problem.

4. Scan Your Terminal

Developers share screens from terminals every day. A terminal can contain more secrets than any other single window:

• Command history showing API keys or database passwords typed at the command line
• Environment variables exported in .zshrc or .bash_profile
• Logs that include token values
• SSH keys visible in open files

If you are sharing a terminal window, scroll through the visible content and check for anything that should not be public. Use history to see what commands you have run recently. If a password appeared in any command, clear that line or clear the history buffer.

5. Check Your Browser History

Your browser address bar is often visible during screen sharing. If you have an admin dashboard, email inbox, or private page open, someone in the meeting can see the URL and possibly read the content.

Before sharing:

• Close unnecessary tabs
• Use a fresh browser window for the demo
• Consider using a dedicated "demo" browser profile with only the tabs you need

6. Look at Your Clipboard

This is the rare one that catches people off guard. On a Mac, if someone copies your clipboard content (with the right tool, which happens more often than you think), they can see what you have copied.

More commonly, if you paste something sensitive into a meeting chat or a shared document during the session, it is now visible to everyone.

7. Verify What People Can Actually See

Most screen sharing tools let you preview what the audience sees before you start. Use it.

• In Zoom, hover over the share button to see the preview
• In Google Meet, click the "Present now" button and review what is selected
• In Discord, check the preview before going live

A preview is the only way to know for sure what your audience is looking at. Don't skip it.

The Tools That Help

Manual checks are great. Automated checks are better. The problem with manual auditing is that you are looking at your own screen and you know what is there. Your brain filters out things it recognizes as "mine." That is a hard filter to override.

Censr automates that filter. It watches your screen continuously, detects secrets, PII, and personal information, and blacks them out before they reach your audience. It runs on your Mac, 100% on-device. Nothing is uploaded.

Think of it as a second set of eyes that never blinks.

The One-Minute Drill

Here is the fastest version of this audit. Run it before every call:

1. 1. Close non-essential windows. (10 seconds)
2. 2. Check your second monitor for open content. (10 seconds)
3. 3. Turn on Do Not Disturb. (5 seconds)
4. 4. Scroll your terminal and visible documents for anything sensitive. (20 seconds)
5. 5. Preview what you are about to share. (15 seconds)

One minute. Thirty seconds if you practice.

It takes more time to recover from a leak than to prevent it.

Bottom Line

The people who leak things on screen share are not careless. They are busy. They are focused on the presentation, the code, the demo. The audit is a habit. Habits are built by doing the same check every time until it becomes automatic.

Start with the one-minute drill. Add automation when you are ready. Either way, the goal is the same: make sure your audience sees what you intend them to see and nothing else.