Develop Reference

Is there a way to use a percent value in window.scrollTo()

I have a window.scrollTo() function on my website. It uses just a number value (or pixels) which works fine in a larger-sized window but does not scroll where I want on mobile devices. Instead, I want to use a percent value (or some dynamic unit) so it scrolls where I want on all devices.

You can measure the screen height and then divide by 100 and with it, you get the unit with percentage.
let unit = document.documentElement.scrollHeight / 100;
const onScroll = () => {
console.log(unit)
window.scrollTo({ top: 30 * unit });
}
body {
height: 2000px;
}
<button onclick="onScroll()">Scroll</button>

detect screen size on iPhone match to IOS 14 and above [duplicate]

How can I get windowWidth, windowHeight, pageWidth, pageHeight, screenWidth, screenHeight, pageX, pageY, screenX, screenY which will work in all major browsers?

You can get the size of the window or document with jQuery:
// Size of browser viewport.
$(window).height();
$(window).width();
// Size of HTML document (same as pageHeight/pageWidth in screenshot).
$(document).height();
$(document).width();
For screen size you can use the screen object:
window.screen.height;
window.screen.width;

This has everything you need to know: Get viewport/window size
but in short:
var win = window,
doc = document,
docElem = doc.documentElement,
body = doc.getElementsByTagName('body')[0],
x = win.innerWidth || docElem.clientWidth || body.clientWidth,
y = win.innerHeight|| docElem.clientHeight|| body.clientHeight;
alert(x + ' × ' + y);
Fiddle
Please stop editing this answer. It's been edited 22 times now by different people to match their code format preference. It's also been pointed out that this isn't required if you only want to target modern browsers - if so you only need the following:
const width = window.innerWidth || document.documentElement.clientWidth ||
document.body.clientWidth;
const height = window.innerHeight|| document.documentElement.clientHeight||
document.body.clientHeight;
console.log(width, height);

Here is a cross browser solution with pure JavaScript (Source):
var width = window.innerWidth
|| document.documentElement.clientWidth
|| document.body.clientWidth;
var height = window.innerHeight
|| document.documentElement.clientHeight
|| document.body.clientHeight;

A non-jQuery way to get the available screen dimension. window.screen.width/height has already been put up, but for responsive webdesign and completeness sake I think its worth to mention those attributes:
alert(window.screen.availWidth);
alert(window.screen.availHeight);
http://www.quirksmode.org/dom/w3c_cssom.html#t10 :
availWidth and availHeight - The available width and height on the
screen (excluding OS taskbars and such).

But when we talk about responsive screens and if we want to handle it using jQuery for some reason,
window.innerWidth, window.innerHeight
gives the correct measurement. Even it removes the scroll-bar's extra space and we don't need to worry about adjusting that space :)

Full 2020
I am surprised that question have about 10 years and it looks like so far nobody has given a full answer (with 10 values) yet. So I carefully analyse OP question (especially picture) and have some remarks
center of coordinate system (0,0) is in the viewport (browser window without bars and main borders) top left corner and axes are directed to right and down (what was marked on OP picture) so the values of pageX, pageY, screenX, screenY must be negative (or zero if page is small or not scrolled)
for screenHeight/Width OP wants to count screen height/width including system menu bar (eg. in MacOs) - this is why we NOT use .availWidth/Height (which not count it)
for windowWidth/Height OP don't want to count size of scroll bars so we use .clientWidth/Height
the screenY - in below solution we add to position of top left browser corner (window.screenY) the height of its menu/tabls/url bar). But it is difficult to calculate that value if download-bottom bar appears in browser and/or if developer console is open on page bottom - in that case this value will be increased of size of that bar/console height in below solution. Probably it is impossible to read value of bar/console height to make correction (without some trick like asking user to close that bar/console before measurements...)
pageWidth - in case when pageWidth is smaller than windowWidth we need to manually calculate size of <body> children elements to get this value (we do example calculation in contentWidth in below solution - but in general this can be difficult for that case)
for simplicity I assume that <body> margin=0 - if not then you should consider this values when calculate pageWidth/Height and pageX/Y
function sizes() {
const contentWidth = [...document.body.children].reduce(
(a, el) => Math.max(a, el.getBoundingClientRect().right), 0)
- document.body.getBoundingClientRect().x;
return {
windowWidth: document.documentElement.clientWidth,
windowHeight: document.documentElement.clientHeight,
pageWidth: Math.min(document.body.scrollWidth, contentWidth),
pageHeight: document.body.scrollHeight,
screenWidth: window.screen.width,
screenHeight: window.screen.height,
pageX: document.body.getBoundingClientRect().x,
pageY: document.body.getBoundingClientRect().y,
screenX: -window.screenX,
screenY: -window.screenY - (window.outerHeight-window.innerHeight),
}
}
// TEST
function show() {
console.log(sizes());
}
body { margin: 0 }
.box { width: 3000px; height: 4000px; background: red; }
<div class="box">
CAUTION: stackoverflow snippet gives wrong values for screenX-Y,
but if you copy this code to your page directly the values will be right<br>
<button onclick="show()" style="">CALC</button>
</div>
I test it on Chrome 83.0, Safari 13.1, Firefox 77.0 and Edge 83.0 on MacOs High Sierra

Graphical answer:
(............)

function wndsize(){
var w = 0;var h = 0;
//IE
if(!window.innerWidth){
if(!(document.documentElement.clientWidth == 0)){
//strict mode
w = document.documentElement.clientWidth;h = document.documentElement.clientHeight;
} else{
//quirks mode
w = document.body.clientWidth;h = document.body.clientHeight;
}
} else {
//w3c
w = window.innerWidth;h = window.innerHeight;
}
return {width:w,height:h};
}
function wndcent(){
var hWnd = (arguments[0] != null) ? arguments[0] : {width:0,height:0};
var _x = 0;var _y = 0;var offsetX = 0;var offsetY = 0;
//IE
if(!window.pageYOffset){
//strict mode
if(!(document.documentElement.scrollTop == 0)){offsetY = document.documentElement.scrollTop;offsetX = document.documentElement.scrollLeft;}
//quirks mode
else{offsetY = document.body.scrollTop;offsetX = document.body.scrollLeft;}}
//w3c
else{offsetX = window.pageXOffset;offsetY = window.pageYOffset;}_x = ((wndsize().width-hWnd.width)/2)+offsetX;_y = ((wndsize().height-hWnd.height)/2)+offsetY;
return{x:_x,y:_y};
}
var center = wndcent({width:350,height:350});
document.write(center.x+';<br>');
document.write(center.y+';<br>');
document.write('<DIV align="center" id="rich_ad" style="Z-INDEX: 10; left:'+center.x+'px;WIDTH: 350px; POSITION: absolute; TOP: '+center.y+'px; HEIGHT: 350px"><!--К сожалению, у Вас не установлен flash плеер.--></div>');

You can also get the WINDOW width and height, avoiding browser toolbars and other stuff. It is the real usable area in browser's window.
To do this, use:
window.innerWidth and window.innerHeight properties (see doc at w3schools).
In most cases it will be the best way, in example, to display a perfectly centred floating modal dialog. It allows you to calculate positions on window, no matter which resolution orientation or window size is using the browser.

To check height and width of your current loaded page of any website using "console" or after clicking "Inspect".
step 1: Click the right button of mouse and click on 'Inspect' and then click 'console'
step 2: Make sure that your browser screen should be not in 'maximize' mode. If the browser screen is in 'maximize' mode, you need to first click the maximize button (present either at right or left top corner) and un-maximize it.
step 3: Now, write the following after the greater than sign ('>') i.e.
> window.innerWidth
output : your present window width in px (say 749)
> window.innerHeight
output : your present window height in px (say 359)

Complete guide related to Screen sizes
JavaScript
For height:
document.body.clientHeight // Inner height of the HTML document body, including padding
// but not the horizontal scrollbar height, border, or margin
screen.height // Device screen height (i.e. all physically visible stuff)
screen.availHeight // Device screen height minus the operating system taskbar (if present)
window.innerHeight // The current document's viewport height, minus taskbars, etc.
window.outerHeight // Height the current window visibly takes up on screen
// (including taskbars, menus, etc.)
Note: When the window is maximized this will equal screen.availHeight
For width:
document.body.clientWidth // Full width of the HTML page as coded, minus the vertical scroll bar
screen.width // Device screen width (i.e. all physically visible stuff)
screen.availWidth // Device screen width, minus the operating system taskbar (if present)
window.innerWidth // The browser viewport width (including vertical scroll bar, includes padding but not border or margin)
window.outerWidth // The outer window width (including vertical scroll bar,
// toolbars, etc., includes padding and border but not margin)
Jquery
For height:
$(document).height() // Full height of the HTML page, including content you have to
// scroll to see
$(window).height() // The current document's viewport height, minus taskbars, etc.
$(window).innerHeight() // The current document's viewport height, minus taskbars, etc.
$(window).outerHeight() // The current document's viewport height, minus taskbars, etc.
For width:
$(document).width() // The browser viewport width, minus the vertical scroll bar
$(window).width() // The browser viewport width (minus the vertical scroll bar)
$(window).innerWidth() // The browser viewport width (minus the vertical scroll bar)
$(window).outerWidth() // The browser viewport width (minus the vertical scroll bar)
Reference: https://help.optimizely.com/Build_Campaigns_and_Experiments/Use_screen_measurements_to_design_for_responsive_breakpoints

With the introduction of globalThis in ES2020 you can use properties like.
For screen size:
globalThis.screen.availWidth
globalThis.screen.availHeight
For Window Size
globalThis.outerWidth
globalThis.outerHeight
For Offset:
globalThis.pageXOffset
globalThis.pageYOffset
...& so on.
alert("Screen Width: "+ globalThis.screen.availWidth +"\nScreen Height: "+ globalThis.screen.availHeight)

If you need a truly bulletproof solution for the document width and height (the pageWidth and pageHeight in the picture), you might want to consider using a plugin of mine, jQuery.documentSize.
It has just one purpose: to always return the correct document size, even in scenarios when jQuery and other methods fail. Despite its name, you don't necessarily have to use jQuery – it is written in vanilla Javascript and works without jQuery, too.
Usage:
var w = $.documentWidth(),
h = $.documentHeight();
for the global document. For other documents, e.g. in an embedded iframe you have access to, pass the document as a parameter:
var w = $.documentWidth( myIframe.contentDocument ),
h = $.documentHeight( myIframe.contentDocument );
Update: now for window dimensions, too
Ever since version 1.1.0, jQuery.documentSize also handles window dimensions.
That is necessary because
$( window ).height() is buggy in iOS, to the point of being useless
$( window ).width() and $( window ).height() are unreliable on mobile because they don't handle the effects of mobile zooming.
jQuery.documentSize provides $.windowWidth() and $.windowHeight(), which solve these issues. For more, please check out the documentation.

I wrote a small javascript bookmarklet you can use to display the size. You can easily add it to your browser and whenever you click it you will see the size in the right corner of your browser window.
Here you find information how to use a bookmarklet
https://en.wikipedia.org/wiki/Bookmarklet
Bookmarklet
javascript:(function(){!function(){var i,n,e;return n=function(){var n,e,t;return t="background-color:azure; padding:1rem; position:fixed; right: 0; z-index:9999; font-size: 1.2rem;",n=i('<div style="'+t+'"></div>'),e=function(){return'<p style="margin:0;">width: '+i(window).width()+" height: "+i(window).height()+"</p>"},n.html(e()),i("body").prepend(n),i(window).resize(function(){n.html(e())})},(i=window.jQuery)?(i=window.jQuery,n()):(e=document.createElement("script"),e.src="http://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js",e.onload=n,document.body.appendChild(e))}()}).call(this);
Original Code
The original code is in coffee:
(->
addWindowSize = ()->
style = 'background-color:azure; padding:1rem; position:fixed; right: 0; z-index:9999; font-size: 1.2rem;'
$windowSize = $('<div style="' + style + '"></div>')
getWindowSize = ->
'<p style="margin:0;">width: ' + $(window).width() + ' height: ' + $(window).height() + '</p>'
$windowSize.html getWindowSize()
$('body').prepend $windowSize
$(window).resize ->
$windowSize.html getWindowSize()
return
if !($ = window.jQuery)
# typeof jQuery=='undefined' works too
script = document.createElement('script')
script.src = 'http://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js'
script.onload = addWindowSize
document.body.appendChild script
else
$ = window.jQuery
addWindowSize()
)()
Basically the code is prepending a small div which updates when you resize your window.

In some cases related with responsive layout $(document).height() can return wrong data that displays view port height only.
For example when some div#wrapper has height:100%, that #wrapper can be stretched by some block inside it. But it's height still will be like viewport height. In such situation you might use
$('#wrapper').get(0).scrollHeight
That represents actual size of wrapper.

I developed a library for knowing the real viewport size for desktops and mobiles browsers, because viewport sizes are inconsistents across devices and cannot rely on all the answers of that post (according to all the research I made about this) : https://github.com/pyrsmk/W

Sometimes you need to see the width/height changes while resizing the window and inner content.
For that I've written a little script that adds a log box that dynamicly monitors all the resizing and almost immediatly updates.
It adds a valid HTML with fixed position and high z-index, but is small enough, so you can:
use it on an actual site
use it for testing mobile/responsive
views
Tested on: Chrome 40, IE11, but it is highly possible to work on other/older browsers too ... :)
function gebID(id){ return document.getElementById(id); }
function gebTN(tagName, parentEl){
if( typeof parentEl == "undefined" ) var parentEl = document;
return parentEl.getElementsByTagName(tagName);
}
function setStyleToTags(parentEl, tagName, styleString){
var tags = gebTN(tagName, parentEl);
for( var i = 0; i<tags.length; i++ ) tags[i].setAttribute('style', styleString);
}
function testSizes(){
gebID( 'screen.Width' ).innerHTML = screen.width;
gebID( 'screen.Height' ).innerHTML = screen.height;
gebID( 'window.Width' ).innerHTML = window.innerWidth;
gebID( 'window.Height' ).innerHTML = window.innerHeight;
gebID( 'documentElement.Width' ).innerHTML = document.documentElement.clientWidth;
gebID( 'documentElement.Height' ).innerHTML = document.documentElement.clientHeight;
gebID( 'body.Width' ).innerHTML = gebTN("body")[0].clientWidth;
gebID( 'body.Height' ).innerHTML = gebTN("body")[0].clientHeight;
}
var table = document.createElement('table');
table.innerHTML =
"<tr><th>SOURCE</th><th>WIDTH</th><th>x</th><th>HEIGHT</th></tr>"
+"<tr><td>screen</td><td id='screen.Width' /><td>x</td><td id='screen.Height' /></tr>"
+"<tr><td>window</td><td id='window.Width' /><td>x</td><td id='window.Height' /></tr>"
+"<tr><td>document<br>.documentElement</td><td id='documentElement.Width' /><td>x</td><td id='documentElement.Height' /></tr>"
+"<tr><td>document.body</td><td id='body.Width' /><td>x</td><td id='body.Height' /></tr>"
;
gebTN("body")[0].appendChild( table );
table.setAttribute(
'style',
"border: 2px solid black !important; position: fixed !important;"
+"left: 50% !important; top: 0px !important; padding:10px !important;"
+"width: 150px !important; font-size:18px; !important"
+"white-space: pre !important; font-family: monospace !important;"
+"z-index: 9999 !important;background: white !important;"
);
setStyleToTags(table, "td", "color: black !important; border: none !important; padding: 5px !important; text-align:center !important;");
setStyleToTags(table, "th", "color: black !important; border: none !important; padding: 5px !important; text-align:center !important;");
table.style.setProperty( 'margin-left', '-'+( table.clientWidth / 2 )+'px' );
setInterval( testSizes, 200 );
EDIT: Now styles are applied only to logger table element - not to all tables - also this is a jQuery-free solution :)

You can use the Screen object to get this.
The following is an example of what it would return:
Screen {
availWidth: 1920,
availHeight: 1040,
width: 1920,
height: 1080,
colorDepth: 24,
pixelDepth: 24,
top: 414,
left: 1920,
availTop: 414,
availLeft: 1920
}
To get your screenWidth variable, just use screen.width, same with screenHeight, you would just use screen.height.
To get your window width and height, it would be screen.availWidth or screen.availHeight respectively.
For the pageX and pageY variables, use window.screenX or Y. Note that this is from the VERY LEFT/TOP OF YOUR LEFT/TOP-est SCREEN. So if you have two screens of width 1920 then a window 500px from the left of the right screen would have an X value of 2420 (1920+500). screen.width/height, however, display the CURRENT screen's width or height.
To get the width and height of your page, use jQuery's $(window).height() or $(window).width().
Again using jQuery, use $("html").offset().top and $("html").offset().left for your pageX and pageY values.

here is my solution!
// innerWidth
const screen_viewport_inner = () => {
let w = window,
i = `inner`;
if (!(`innerWidth` in window)) {
i = `client`;
w = document.documentElement || document.body;
}
return {
width: w[`${i}Width`],
height: w[`${i}Height`]
}
};
// outerWidth
const screen_viewport_outer = () => {
let w = window,
o = `outer`;
if (!(`outerWidth` in window)) {
o = `client`;
w = document.documentElement || document.body;
}
return {
width: w[`${o}Width`],
height: w[`${o}Height`]
}
};
// style
const console_color = `
color: rgba(0,255,0,0.7);
font-size: 1.5rem;
border: 1px solid red;
`;
// testing
const test = () => {
let i_obj = screen_viewport_inner();
console.log(`%c screen_viewport_inner = \n`, console_color, JSON.stringify(i_obj, null, 4));
let o_obj = screen_viewport_outer();
console.log(`%c screen_viewport_outer = \n`, console_color, JSON.stringify(o_obj, null, 4));
};
// IIFE
(() => {
test();
})();

This how I managed to get the screen width in React JS Project:
If width is equal to 1680 then return 570 else return 200
var screenWidth = window.screen.availWidth;
<Label style={{ width: screenWidth == "1680" ? 570 : 200, color: "transparent" }}>a </Label>
Screen.availWidth

Height change closes sidebar

I have a sidebar while displaying on mobile and entering the search input field, it closes once mobile keyboard is open and also if the height of the page is changed in browser inspection as shown in the following images:
this is the only code contains innerHeight
function fitContent() {
var top = $(window).scrollTop() < 340 ? 270 - $(window).scrollTop() : 0;
rightSide.css("top", top + "px");
content.css("min-height", window.innerHeight - 130 + "px");
var window_Width = window.innerWidth;
if (window_Width < 1366) {
closeRightSide();
} else {
openRightSide();
}
}
and fitContent functions runs under window.resize and document.ready. Also that sidebar has open and close functions which toggle between two classes and changes the boolean value of an attribute.
function openRightSide() {
body.removeClass("shrink");
body.addClass("expand");
rightSide.attr("data-expand", "true");
}
I noticed that data-expand attribute turns to false when the height is changed. and there is no additional code or css related to it.
The Question:
How can I prevent height changes from closing the sidebar? What piece of code can I use?

How to detect iOS7 Safari height change on scrolling - JavaScript

In Safari on iPhone iOS7 a scroll down will show the menus at the top and bottom and a scroll up will hide them - effectively changing the height of the screen.
How do I listen for this slight change in height?
I have an element that changes height depending on the height of the screen, but in iOS7 it's not really behaving well.

To listen to window resize events we can use window.addEventListener("resize", myFunction);
or using jQuery $(window).resize(myFunction());
I had a related problem but reversed -- a small window resize that happens on-scroll on iOS devices was unnecessarily triggering my on-resize logic.
One workaround can be just ignoring a small vertical resize (approx 40px should be ok)
An example solution (using jQuery)
const ignoreVerticalResizeTreshold= 40;
let vpHeight= 0;
let vpWidth= 0;
$(window).resize(function() {
// Do stuff (on any window resize event)
// return if no horizontal resize happened and vertical resize is below the set treshold
if ($(window).innerWidth() === vpWidth && (($(window).innerHeight() >= (vpHeight - ignoreVerticalResizeTreshold / 2)) || ($(window).innerHeight() <= (vpHeight + ignoreVerticalResizeTreshold / 2)))) {
return;
}
// Do more stuff
vpHeight = $(window).innerHeight();
vpWidth = $(window).innerWidth();
});

In a recent React project I set a CSS var to the window.innerHeight on resize.
const setAppHeight = (): void => {
const doc = document.documentElement;
doc.style.setProperty('--app-height', `${window.innerHeight}px`);
};
const debouncedEventHandler = useMemo(
() => debounce(setAppHeight, 300),
[],
);
useEffect(() => {
window.addEventListener('resize', debouncedEventHandler);
setAppHeight();
return () => {
debouncedEventHandler.cancel();
};
}, []);
That var was set normally in CSS and used whenever something needed
:root {
--app-height: 100%;
}
.whatever {
height: var(--app-height);
}

Dynamic Image Resizing

I have an image on a webpage that needs to be stretched to fit the available space in the window whilst maintaining its proportion. Here's what I've got:
http://www.lammypictures.com/test/
I would like the large image to proportionally stretch to match the height and widths of the browser, minus the size of the divs to the left and bottom.
So the problem is 2 fold really; first i need to get the max height and width minus the link and image bars, secondly i need to resize the image on a browser resize whilst maintaining proportions.
Any help would be much appreciated.
Cheers
CIP

You could try using jQuery ui scaling effect:
$(document).ready(function () {
resizeImage(); // initialize
$(window).resize(function () {
resizeImage(); // initialize again when the window changes
});
function resizeImage() {
var windowHeight = $(window).height() - $('#nav').height(),
windowWidth = $(window).width(),
percentage = 0;
if (windowHeight >= windowWidth) {
percentage = (windowWidth / $('#image').width() ) * 100;
}
else {
percentage = ( windowHeight / $('#image').height() ) * 100;
}
$('#image').effect('scale', { percent : percentage }, 1);
};
});
Tested and works great, however, a few tweaks maybe needed to get it just the way you like it.

You may just not setup the image element width and height attributes, and write next styles:
.hentry img { max-width: 100%; }
And it will shrink relative to the minimum side.
P.S. But not in position: absolute; block which not have any size. Set up the parent block to relative positioning.