Share your screen in a lesson
Screen sharing lets you (or your student) show what's on your computer to the other side of the lesson — a webpage, a presentation, a document, anything. It's the right tool when the content you need to show isn't on the whiteboard. For most teaching material, the whiteboard is faster and more interactive; reach for screen sharing when the content lives elsewhere.
Screen sharing is available to teachers and students on every Class Spot plan, including Free.
How to share your screen
- In the lesson room, find the screen-sharing button on the lesson toolbar.
- Click it. Your browser will pop up a dialog asking what to share.
- Pick one of the three options the browser offers:
- Entire screen — everything on your monitor, including notifications and taskbar.
- Window — a single application window (one Chrome window, one PowerPoint, one Word doc).
- Browser tab — a single tab in the browser you're using.
- Click Share.
The other side sees your selection inside the lesson view. The board is still there — they can switch between the board and the shared screen as needed.
[Screenshot: the screen-share button on the Class Spot lesson toolbar]
[Screenshot: the browser's "Choose what to share" dialog with Entire screen / Window / Tab tabs]
Which option should you pick?
| Option | Use when | Watch out for |
|---|---|---|
| Browser tab | Showing a single website, online tool, or Google Doc. Cleanest option — only that tab is shared. | If you switch tabs in the browser, the student won't see the new one. |
| Window | Showing a specific app like PowerPoint, Word, or a desktop video player. | Notifications inside that window are visible. Other apps are hidden. |
| Entire screen | Demonstrating workflows that span apps, or showing system settings. | Everything is visible — incoming notifications, other windows, your wallpaper. Close anything you don't want the student to see. |
For privacy, prefer Window or Browser tab over Entire screen whenever possible.
Stop sharing
There are two ways to stop:
- A Stop sharing bar appears at the bottom or top of the browser window while a share is active. Click Stop sharing there.
- Click the screen-sharing button again in the lesson toolbar to toggle it off.
The shared view ends immediately for the student.
[Screenshot: the "Stop sharing" bar at the bottom of the browser during an active share]
Browser permissions — first-time setup
The first time you click the screen-sharing button, your browser will ask for permission. Allow it. After that, most browsers remember the choice for the site.
macOS
On macOS, your browser also needs permission from the operating system to record the screen. If the share starts but the student sees a black rectangle:
- Open System Settings → Privacy & Security → Screen Recording.
- Find your browser in the list (Chrome, Safari, Edge).
- Toggle the switch on.
- Quit the browser completely and reopen it. Don't skip this step — macOS only applies the new permission after a full restart.
- Try sharing again.
[Screenshot: the macOS Screen Recording privacy panel with Chrome highlighted]
Windows
Windows usually doesn't require an OS-level permission for screen sharing — the browser handles it. If sharing fails, check that no antivirus or privacy tool is blocking your browser.
Browser choice
Use Chrome or Safari for the best results. Firefox has known issues with screen sharing during Class Spot lessons; if you're on Firefox, switch browsers before sharing.
What the student sees
Your student sees the shared content in their lesson view. They can:
- Watch the share live, including your cursor movement.
- Switch between the shared screen and the whiteboard at any time.
They cannot click, type, or interact with your shared screen. Screen sharing is one-way display; if you need them to interact, switch to the whiteboard or have them upload the file there.
Have your student share their screen
Students can share too — useful when they want to show you their homework, a website they're reading, or a question they're stuck on.
- Ask the student to click the screen-sharing button in their lesson room (same button as the teacher's).
- The browser asks them what to share.
- They pick a window or tab and click Share.
You'll see their selection in your lesson view. Use the Tracking tool on the whiteboard alongside their screen share to know exactly where they're looking.
Audio during a screen share
Sharing your screen does not automatically share audio. If you're playing a video or audio clip you want the student to hear:
- Browser tab share: check the Share tab audio box in the share dialog before you click Share. Most browsers offer this option for tab-level sharing.
- Window or full-screen share: audio sharing depends on the browser and operating system. Safari does not share system audio. On Chrome (Windows), you can sometimes enable it; on Chrome (macOS), system audio sharing is unreliable.
For reliable audio of a clip, upload the audio file directly to the whiteboard instead — see Use the whiteboard during a lesson.
Tips
- Close personal apps first. Email, chat, and notifications can pop up over a share. Quit anything you don't want the student to glimpse.
- Resize before sharing. The student sees the share scaled to their screen — make sure your text isn't tiny.
- Mute notifications. On macOS, turn on Focus mode. On Windows, turn on Do Not Disturb. One badge from your bank during a share is a memory the student keeps.
- Don't share the lesson tab itself. Sharing the same browser tab the lesson is in creates a recursive view that confuses both sides. Pick a different tab or window.
- For PDFs and slides, upload them to the board. The whiteboard renders PDF and PPT natively and lets the student annotate alongside you. Screen sharing is a fallback when you can't get the content onto the board.
Troubleshooting
The "Share" button doesn't do anything.
- Reload the page once (Ctrl/Cmd + R) and try again. Browser permissions sometimes hang on first use.
- Check the lock icon in the address bar. Make sure classpot.com has permission to share your screen — set it to Allow if it's blocked.
The student sees a black or frozen rectangle.
- macOS: grant your browser screen-recording permission and restart the browser (see above).
- The connection may be unstable. Check your internet speed (5 Mbps up minimum). If the connection is poor, screen sharing is heavier than camera-only — turn off your camera while sharing.
My audio isn't coming through.
- The default share doesn't include audio. Use Browser tab share with the Share tab audio checkbox enabled.
- For prepared audio or video clips, upload the file to the whiteboard instead.
I'm using Firefox and sharing doesn't work.
- Firefox is not recommended for Class Spot lessons. Open the lesson link in Chrome or Safari.
Sharing makes the lesson laggy for both sides.
- Screen sharing uses more bandwidth than camera-only. If your connection is borderline, turn off your camera during the share and turn it back on after.
- Share a Window or Tab instead of the Entire screen — both are lighter than full-screen sharing.
Can the student stop my share or take over?
- No. Each side controls their own share. You can stop your own share, the student can stop theirs. Neither can stop the other's.
If nothing above helps
Contact us:
- In-product chat — click the green chat bubble in the bottom-right of your cabinet, then Start Conversation.
- Email — info@classpot.com.