Sharing an application in Webex sends that one app's window content and nothing else: no desktop, no taskbar, no notification banners, and nothing you drag in front of it, because Webex captures the application rather than the pixels sitting on top of it. Sharing a screen sends a whole display live, everything on it included. The Webex-specific catch is scaling: whatever you share is fitted to each participant's own window, so a small app window on your desktop arrives large and soft on theirs. Webex also has a third option, share a portion of your screen, which streams only what falls inside a rectangle you draw.
What Webex puts in the stream
Three capture models sit behind one Share button, presented as equals in the picker: your displays, your running applications, and a region of a display. They behave very differently once the call is live.
| Share an application | Share a screen | Share a portion | |
|---|---|---|---|
| What viewers get | That app's window content | The whole display, live | Only what is inside the rectangle |
| You alt-tab to your inbox | They still see the app | They see your inbox | They see whatever is in the box |
| A window dragged over it | Excluded | Included | Included, if it lands in the box |
| Notification banner | Not sent | Sent, with the message preview | Sent if it pops up in the box |
| Sharpness ceiling | The app window's pixel size | Display resolution | The rectangle's pixel size |
| You minimise the source | Viewers lose the picture | Not applicable | Not applicable |
| File picker or print dialog | Often missing, separate window | Visible | Visible if it opens in the box |
| Second window of the same app | May be included | Included if on that display | Included if inside the box |
Two rows deserve a test rather than trust. Dialogs vary by app: some draw them inside their own frame, some hand the job to a separate operating system window the share never sees. And Webex's picker lists applications, not windows, so on some client versions a second window of the same program rides along with the share.
Your window size decides their picture quality
Webex fits shared content to each participant's viewing area, preserving aspect ratio, and stretches it until it touches the edges. There is no polite small version on the other side, however small the window is on your desktop.
Work it through. You share a code editor sitting in a 960 by 600 window. Your interviewer is watching full screen with roughly 1700 by 1000 of content area. Webex scales those 960 pixels up to about 1700, near enough 1.7 times, and every glyph of your 11pt font is interpolated across pixels that were never rendered. Crisp on your monitor, soft-edged on theirs, and they will squint rather than interrupt you.
Aspect ratio makes it stranger. A tall narrow window, a chat panel or a docked terminal, is not tucked into a corner at its real size. It is scaled to their full height and pillarboxed with grey down both sides.
- Size the window before you press Share. Resizing the source mid-share re-fits everyone's view, a visible jump on their side.
- Raise the app's own zoom rather than relying on the upscale. Ctrl and plus renders text at more real pixels, which survives scaling. Stretching a small render does not.
- Use the optimise dropdown. Text and images favours a sharp still picture, which is what code and slides need. Motion and video favours frame rate and unlocks computer audio.
- Viewers can override you with their own fit and zoom controls. Almost nobody does, and nobody announces that your text is unreadable.
In a live coding round, the interviewer's read of your solution is capped by how big your editor window was when you pressed Share. That is why the Code Copilot capture runs off a hotkey rather than a window switch.
What can sit in front of an application share, and what cannot
Because Webex captures the application, anything layered over it stays out. Your notes, a chat window, a notification banner, a folder dragged across it: none of that reaches the meeting. It is the strongest reason to share an application in Webex.
Covering the shared app is safe by design. Minimising it is not, because there is nothing left to send.
Minimise the source and Webex has no frames at all, so viewers get a dead picture, a held frame or a blank area, with nothing on their side explaining why. How the covered area renders is the part that varies: the intended result is your app carrying on underneath, but some capture paths, depending on client version and graphics driver, paint a plain block where the overlapping window sat.
Worth sixty seconds, then. Join your own meeting from your phone, share the application at the size you will really use, and drag File Explorer across it. If the app keeps flowing underneath on the phone, covering is safe on your machine. Read the phone at arm's length while you are there: if you cannot make out your own code, neither can the interviewer.
Show or hide the Webex App window while you share
Webex has a setting, under Sharing in the desktop app's settings, that decides whether your own Webex window stays visible while you present. Wording and placement shift between versions, so look for the sharing section rather than a precise label.
Hidden, the usual default, the window steps aside the instant sharing starts and you drive the meeting from the floating control bar that drops down when you hover at the top of the screen. That is why your controls seem to vanish the second a share begins. Shown, the window stays put, participant list and chat readable while you talk.
Which you want depends on the share type. With an application share, showing the window costs nothing in the stream, since only the selected app is captured, so that is the setting for a single monitor when you need to watch chat. With a full screen share it is the reverse: a visible Webex window on the shared display puts the participant list, the chat panel and every incoming message into the meeting, private ones included.
Sharing a portion of your screen
Open the share picker
Click Share in the meeting. Alongside the thumbnails of your displays and applications sits the option to share a portion of your screen.
Frame the region
A resizable outline appears on your desktop. Drag its edges around what you want visible: one pane of an IDE, the top half of a spreadsheet, a browser panel. Everything outside it stays out.
Keep it clear of the bottom right
Notification banners appear there by default, so a rectangle reaching into that corner broadcasts a message preview. Turn on Do not disturb in Settings, System, Notifications first anyway.
Expect it to fill their window too
The fit rule still applies, so a tight crop of small text arrives softer than the same content from a large window. Set the frame once: moving or resizing it mid-share re-fits everyone's view.
Region sharing wins when the thing worth showing is not a whole application: one terminal among four, a comparison you arranged by hand. It loses the moment you need to move around, because the rectangle is anchored to the screen, not to your content.
Where this advice runs out
Application sharing is a framing tool, not a privacy guarantee. The edges are soft: an app that paints outside its own frame, an extension popup, a helper window from the same program. Webex meetings are recorded routinely too, so a mistake is not a moment that passes, it is a file with a transcript.
On our own product, plainly. The OfferPilot AI overlay is excluded from screen capture at the operating system level, so it does not appear in a Webex application share, a full screen share, a portion share, or a recording, while staying visible on your own monitor. That claim should stay narrow. It does nothing about a webcam, a person in the room, a lockdown browser or a proctoring agent on a supervised assessment, and nothing about the fact that reading from a screen looks like reading from a screen. In a monitored exam it is the wrong tool, and we would rather say so. Windows 10 and 11 only, and the free tier on the pricing page lets you check the capture behaviour in a solo Webex meeting yourself.
Which one to pick
- Application when you will stay inside one app. Enlarge it first so the upscale works in your favour.
- Screen when you will cross apps, open file dialogs or drag things about. Clean the display first, and move the Webex window off it if you can.
- Portion when the useful thing is smaller than a window and will not move.
- Either way, check it once on a second device. Webex behaviour differs enough across versions that a minute of testing beats any guide, this one included.
Get the size right and most Webex share complaints disappear, because nearly all of them are the fit rule working as designed. If your calls are interviews, the Interview Copilot page covers the rest.
Related guides
- Zoom Share Screen vs Share Window: What They Actually See
- Will My Notifications Show When I Share My Screen in Teams?
- Microsoft Teams Share Window vs Share Screen: What Others See
- How Apps Hide From Screen Sharing on Windows (and the Limits)
- Does Screen Sharing Show My Second Monitor? What Each App Sends