Screen Share Test
Share this test card in Teams or Zoom and see what your viewers can really read. It has text, pointer, ink-colour, grid and motion rows, and a calculator for how much a big display is scaled down. Free, with no signup, and the page never captures your screen.
Enter the size of the display you will share, in pixels (Windows Settings › System › Display shows it).
Your display fits inside 1920 x 1080, so this estimate shows no shrinking. Motion and compression can still soften the picture, so run the card in a call.
Screen share test card
Press "Open full screen" on the display you plan to share, then share that screen in your meeting app. Everything below is plain HTML except the light and dark switch and the motion lanes.
1 · Text ladder
10 pxThe quick brown fox jumps over the lazy dog 0123456789
12 pxThe quick brown fox jumps over the lazy dog 0123456789
14 pxThe quick brown fox jumps over the lazy dog 0123456789
16 pxThe quick brown fox jumps over the lazy dog 0123456789
20 pxThe quick brown fox jumps over the lazy dog 0123456789
28 pxThe quick brown fox jumps over the lazy dog 0123456789
11 pxconst total = items.reduce((a, b) => a + b, 0); // 1 l I | 0 O
12 pxconst total = items.reduce((a, b) => a + b, 0); // 1 l I | 0 O
14 pxconst total = items.reduce((a, b) => a + b, 0); // 1 l I | 0 O
16 pxconst total = items.reduce((a, b) => a + b, 0); // 1 l I | 0 O
2 · Pointer sizes
Move your real pointer next to these. If you can tell yours from the 24 px arrow, so can your viewers.
3 · Grey levels
4 · Ink colours on light and dark
5 · One-pixel grid
Clean, even lines mean the picture arrived unscaled. Shimmer, bands or grey mush mean it was resized.
6 · Motion lanes
This browser is drawing – frames a second. Each block steps across its lane that many times a second.
How to test your screen share
- Open the card on the display you will share. Press "Open full screen" so the card fills that display. Press Esc to leave.
- Start a meeting by yourself, or with a colleague. In Teams, start a meeting you can join from a second device or ask a colleague to join for a minute. In Zoom, start a new meeting and invite one person. Viewers see what you share, so you need a second pair of eyes or a second device.
- Share the whole screen that shows the card. Choose the screen, not a single window, in the share menu. Later, repeat with one window to see the difference.
- Ask the viewer five questions. What is the smallest text row they can read? Can they see all five pointer sizes? Which ink colours disappear on the light or the dark band? Do the grid lines look clean? Which motion lanes look smooth?
- Change one thing and test again. Display scaling, window or screen, light or dark ink, an "optimize for video" option. The card shows which change helped.
No second person? In Teams, open More › Settings › Call health during the share and scroll to Screen Sharing: it lists the frame rate and resolution of your share (Microsoft Learn).
What viewers receive in Teams and Zoom
Teams sends a shared screen at a resolution and frame rate that depend on what you share, within a documented range. Zoom publishes no figure we could find, so this page gives none. Sources checked on October 31, 2026.
| Setting | Teams | Source |
|---|---|---|
| Resolution sent and received | 160 x 90 to 1920 x 1080 | Monitor call and meeting quality |
| Frame rate sent and received | 1 to 30 fps | Monitor call and meeting quality |
| Default for static content | A low frame rate, so documents and spreadsheets stay as sharp as possible | Fix screen sharing video display lag |
| Shared video that lags | Ctrl+Alt+Shift+T in Teams 1.6.00.12455 or later toggles high-motion sharing; resolution may drop. Microsoft says the shortcut will be deprecated for a presenter toolbar option that optimizes for video | Fix screen sharing video display lag |
| Where to read your numbers | More › Settings › Call health › Screen Sharing | Fix screen sharing video display lag |
| Zoom | Not published on the pages checked, so not claimed here. Measure it with the card above | Your own test |
How a larger display is scaled (an estimate)
If the picture is fitted inside 1920 x 1080 without being enlarged, a bigger display shrinks by a fixed ratio. This is our arithmetic from Microsoft's 1920 x 1080 ceiling, not a Microsoft figure, and your meeting app may crop or scale differently.
| Your display | Viewers get | Scale | 16 px text arrives as |
|---|---|---|---|
| Laptop 1366 x 768 | 1366 x 768 | 100% | 16 px |
| Full HD 1920 x 1080 | 1920 x 1080 | 100% | 16 px |
| 1920 x 1200 | 1728 x 1080 | 90% | 14.4 px |
| QHD 2560 x 1440 | 1920 x 1080 | 75% | 12 px |
| 2560 x 1600 | 1728 x 1080 | 68% | 10.8 px |
| Ultrawide 3440 x 1440 | 1920 x 804 | 56% | 8.9 px |
| 4K 3840 x 2160 | 1920 x 1080 | 50% | 8 px |
How to read the card
| Row | What it tells you | If it fails |
|---|---|---|
| Text ladder | The smallest type viewers can read, in interface and code fonts | Raise Windows scaling in Settings › System › Display › Scale, or zoom the app with Ctrl and the plus key |
| Pointer sizes | Whether viewers can find your pointer | Enlarge it in Settings › Accessibility › Mouse pointer and touch, or add a halo |
| Grey levels | Whether faint secondary text survives compression | Darken the text or switch the app to high contrast before you share |
| Ink colours | Which pen colours vanish on light or dark pages | Pick a colour that reads on both, and make strokes thicker than 2 px |
| One-pixel grid | Whether the picture was resized on the way | Share a smaller display or one window, or lower the display resolution to 1920 x 1080 for the call |
| Motion lanes | Which frame rates the call actually carries | Lanes that jump mean a low frame rate; try the video option in your meeting app |
The card checks the picture, not the sound or the network. If everything on it looks right and viewers still struggle, the cause is usually the connection, which the call-quality pages of your meeting app cover.
Tips before a screen share
- Test on the real display. A laptop and an external monitor have different sizes, so run the card on the one you will share.
- Test the real app. Share the same window or screen you will use in the meeting, not a different one, so you see what viewers will see.
- Close notifications first. Pause chat pop-ups and email banners, then rerun the card to confirm none appears on screen.
- Keep a screenshot of a good result. Next time, compare the new call with it instead of guessing what changed.
- Test the day before. A few minutes with the card leaves time to change scaling or settings, not minutes before you start.
Who it is for
Presenters, teachers and trainers
Check that students and clients can read your slides and code before the session. Keep the presentation timer on a second screen while you run it.
Anyone who demos software
See whether menus, small icons and a 12 px label survive the share. SHARA's screen zoom enlarges the part you are showing instead of lowering your whole resolution.
Privacy
The test card is ordinary page content. This page does not capture, record or upload your screen and never asks for screen permission: your meeting app does the sharing. The calculator runs in your browser, and only the display size you last entered is kept in this browser's local storage, on this device. The site counts visits and tool use in aggregate.
Learn more
Teams screen share blurry
Fixes by likely cause: the 1080p cap, display scaling, hardware acceleration and window or screen.
How to share screen on Teams
Screen, window and PowerPoint Live, with sound, and what viewers see.
Annotate in Teams
Draw on a shared screen with Teams' own tool first, and what to use when it can't.
Screen share test questions
Is the screen share test free?
Does it record or upload my screen?
How do I test my screen share in Teams?
How do I test screen sharing in Zoom?
What resolution do viewers see in a Teams screen share?
Why does my shared screen look blurry?
Why does shared video look choppy in Teams?
Can SHARA make my shared screen easier to read?
Make small details easy to see in your call
The test shows what viewers can read. SHARA fixes it on the spot: a cursor halo viewers can't lose and a white flash on every click, free over any Windows app. Live Zoom and Lens, which enlarge the part you are discussing instead of lowering your whole resolution, are included free for your first 14 days, then it's a one-time upgrade.
Free forever: cursor halo, click animation, Pen, Laser, Arrow, Text, Eraser, Screenshot and the Ctrl+Space Wheel. Every Pro tool is free for your first 14 days, with no card and no account. After that, Pro is a one-time purchase ($19.99 in the US).
Mashyo makes SHARA. Microsoft's Teams screen sharing limits checked on October 31, 2026 at support.microsoft.com and learn.microsoft.com. By Mashyo, founder of SHARA. Last updated: October 31, 2026.