The Window.screenY
read-only property returns the vertical distance, in CSS pixels, of the top border of the user's browser viewport to the top edge of the screen.
Note: An alias of screenY
was implemented across modern browsers in more recent times — Window.screenTop
. This was originally supported only in IE but was introduced everywhere due to popularity.
Syntax
topWindowPos = window.screenY
Returns
A number equal to the number of CSS pixels from the top edge of the browser viewport to the top edge of the screen.
Examples
In our screenleft-screentop example, you'll see a canvas onto which has been drawn a circle. In this example we are using Window.screenLeft
/Window.screenTop
plus Window.requestAnimationFrame()
to constantly redraw the circle in the same physical position on the screen, even if the window position is moved.
initialLeft = window.screenLeft + canvasElem.offsetLeft; initialTop = window.screenTop + canvasElem.offsetTop; function positionElem() { let newLeft = window.screenLeft + canvasElem.offsetLeft; let newTop = window.screenTop + canvasElem.offsetTop; let leftUpdate = initialLeft - newLeft; let topUpdate = initialTop - newTop; ctx.fillStyle = 'rgb(0, 0, 0)'; ctx.fillRect(0, 0, width, height); ctx.fillStyle = 'rgb(0, 0, 255)'; ctx.beginPath(); ctx.arc(leftUpdate + (width/2), topUpdate + (height/2) + 35, 50, degToRad(0), degToRad(360), false); ctx.fill(); pElem.textContent = 'Window.screenLeft: ' + window.screenLeft + ', Window.screenTop: ' + window.screenTop; window.requestAnimationFrame(positionElem); } window.requestAnimationFrame(positionElem);
These work in exactly the same way as screenX
/screenY
.
Also in the code we include a snippet that detects whether screenLeft
is supported, and if not, polyfills in screenLeft
/screenTop
using screenX
/screenY
.
if(!window.screenLeft) { window.screenLeft = window.screenX; window.screenTop = window.screenY; }
Specifications
Specification | Status | Comment |
---|---|---|
CSS Object Model (CSSOM) View Module The definition of 'Window.screenY' in that specification. |
Working Draft | Initial definition. |
Browser compatibility
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
screenY | Chrome Full support Yes | Edge Full support 12 | Firefox
Full support
Yes
| IE Full support Yes | Opera Full support Yes | Safari Full support Yes | WebView Android Full support Yes | Chrome Android Full support Yes | Firefox Android
Full support
Yes
| Opera Android Full support Yes | Safari iOS Full support Yes | Samsung Internet Android Full support Yes |
Legend
- Full support
- Full support
- See implementation notes.
- See implementation notes.