Center a position:fixed element

B

BalusC

You basically need to set top and left to 50% to center the left-top corner of the div. You also need to set the margin-top and margin-left to the negative half of the div's height and width to shift the center towards the middle of the div.

Thus, provided a <!DOCTYPE html> (standards mode), this should do:

position: fixed;
width: 500px;
height: 200px;
top: 50%;
left: 50%;
margin-top: -100px; /* Negative half of height. */
margin-left: -250px; /* Negative half of width. */

Or, if you don't care about centering vertically and old browsers such as IE6/7, then you can instead also add left: 0 and right: 0 to the element having a margin-left and margin-right of auto, so that the fixed positioned element having a fixed width knows where its left and right offsets start. In your case thus:

position: fixed;
width: 500px;
height: 200px;
margin: 5% auto; /* Will not center vertically and won't work in IE6/7. */
left: 0;
right: 0;

Again, this works only in IE8+ if you care about IE, and this centers only horizontally not vertically.

I found that trick in css-tricks.com/…. But when I change the width and height, it's not moving center. Ya, I should change the margin-left and top when change height and width.

FYI: this will correctly position things in the middle, but unfortunately you lose your scroll-bars - any content clipped off by the viewport won't be reachable, even if you scroll, because the fixed position is based on the viewport, not the page. So far, the only solution I've found to that is with javascript.

Groxx I think you could put scroll bars inside a div in the pop up using the overflow property.

Besides, for this one you need to know the element's width.

ah. nm if thats the case, i mean of course the browser size will be dynamic, not sure why that was in the question. instead i thought he meant that the popup dimensions needed to be dynamic. thats the case for me so im using transform: translate(-50%, -50%); works great except not on IE8.

J

Josh Crozier

I want to make a popup box centered to the screen with dynamic width and height.

Here is a modern approach for horizontally centering an element with a dynamic width - it works in all modern browsers; support can be seen here.

Updated Example

.jqbox_innerhtml {
    position: fixed;
    left: 50%;
    transform: translateX(-50%);
}

For both vertical and horizontal centering you could use the following:

Updated Example

.jqbox_innerhtml {
    position: fixed;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
}

You may wish to add in more vendor prefixed properties too (see the examples).

I'm using this approach to horizontally center a fixed positioned image which width is greater than window width and working fine atleast in current Firefox, Chrome, IE 11 and Edge versions.

In my testing this works very well (behind prefixes), Win10 Edge 14, Win7 IE9+, Win10 Chrome, OSX Chrome, iPad4 Chrome & Safari, Android 4.4+ Chrome. Only failure for me was Android 4.0 where the translation did not occur.

@ahnbizcad, this works in desktop browsers like Chrome 61, Safari 11 and FireFox 65, but not in Chrome 61 on Android 6, the accepted answer works in all browsers.

This makes images blurry in Chrome.

Somehow only approach that worked proper across all browser with my img. Thanks a bunch!

W

Will Prescott

Or just add left: 0 and right: 0 to your original CSS, which makes it behave similarly to a regular non-fixed element and the usual auto-margin technique works:

.jqbox_innerhtml
{
  position: fixed;
  width:500px;
  height:200px;
  background-color:#FFF;
  padding:10px;
  border:5px solid #CCC;
  z-index:200;
  margin: 5% auto;
  left: 0;
  right: 0;
}

Note you need to use a valid (X)HTML DOCTYPE for it to behave correctly in IE (which you should of course have anyway..!)

In what sense? The parent element is the body element, which has no borders. If you added border properties to the body (?!) then sure it would be affected, as would the 50% technique I imagine. I assure you it works just fine with the given parameters, just verified in every browser I have handy, and has the added benefit of not being dependent on the width of the element.

All I did was add those 2 properties and a doctype to the OP's example HTML. However on further testing it seems that IE7 (or 8 in compat mode) is the problem - it seems it does not respect the value of the right property if left is also set! ( msdn.microsoft.com/en-us/library/… notes that left and right only have "partial" support in IE7). OK, I concede this solution is no good if IE7 support is important, but a great trick to remember for the future :)

this should be the accepted answer. I had two fixed positions one for the opacity mask another for the modal. this was the only way I could center the fixed position modal in the center of the screen. Awesome answer who would have thought?

I agree, this should be the accepted answer. It works perfectly in responsive design, too, as it is not dependant on width.

I would suggest to simplify the answer, as some of the css is relevant only for the OP. All you need is position: fixed; left: 0; right: 0; margin: 0 auto; .

m

moritzg

Add a container like:

div {
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
  text-align: center;
}

Then put your box into this div will do the work.

Edit: as mentioned in the comments, the inner content needs to be set to display: inline-block assuming there're two divs like:

    <div class="outer">
        <div class="inner">
             content goes here
        </div>
    </div>

Then the CSS for the inner needs to be:

    .outer {
        position: fixed;
        text-align: center;
        left: 0;
        right: 0;
    }
    .inner {
        display: inline-block;
    }

Together with the outer div having a left: 0; right:0; and text-align: center this will align the inner div centered, without explicitly specifying the width of the inner div.

"text-align: center" didn't work for me in centering the internal div.

The internal box needs to be display: inline-block for this to work. (Some other display values might also work, such as table.)

a better approach to the above mentioned css would be adding margin:auto; and changing width to width:50% or width:400px. then the contents can be straight text, block elements, or inline elements.

This solution has the added benefit of not blurring the textual content in MSIE and Chrome which occurs when "transform" is used.

B

Bob

Just add:

left: calc(-50vw + 50%);
right: calc(-50vw + 50%);
margin-left: auto;
margin-right: auto;

This doesn't work with position: fixed, which is what the question is about. If I'm wrong, please edit your answer to include a runnable code snippet.

It works with position: fixed, provided set the max-width or width to the element.

p

proseosoc

Center fixed position element (the simple & best way I know)

position:fixed;
top: 0; left: 0;
transform: translate(calc(50vw - 50%));

For centering it horizontally & vertically (if height is same as width)

position:fixed;
top: 0; left: 0;
transform: translate(calc(50vw - 50%), calc(50vh - 50%));

Both of these approaches will not limit centered element's width less than viewport width, when using margins in flexbox, inside centered element

best solution here

p

praffessorr

#modal {
    display: flex;
    justify-content: space-around;
    align-items: center;
    position: fixed;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
}

inside it can be any element with diffenet width, height or without. all are centered.

B

BjarkeCK

This solution does not require of you to define a width and height to your popup div.

http://jsfiddle.net/4Ly4B/33/

And instead of calculating the size of the popup, and minus half to the top, javascript is resizeing the popupContainer to fill out the whole screen...

(100% height, does not work when useing display:table-cell; (wich is required to center something vertically))...

Anyway it works :)

H

Holger Just

left: 0;
right: 0;

Was not working under IE7.

Changed to

left:auto;
right:auto;

Started working but in the rest browsers it stop working! So used this way for IE7 below

if ($.browser.msie && parseInt($.browser.version, 10) <= 7) {                                
  strAlertWrapper.css({position:'fixed', bottom:'0', height:'auto', left:'auto', right:'auto'});
}

Do you mind editing your answer to include the entire solution?

This won't work without an auto margin on left and right sides.

A

Aseem

I used vw (viewport width) and vh (viewport height). viewport is your entire screen. 100vw is your screens total width and 100vh is total height.

.class_name{
    width: 50vw;
    height: 50vh;
    border: 1px solid red;
    position: fixed;
    left: 25vw;top: 25vh;   
}

F

Flafy

This one worked the best for me:

    display: flex;
    justify-content: center;
    align-items: center;
    position: fixed;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;

F

Flimm

You can basically wrap it into another div and set its position to fixed.

.bg { position: fixed; width: 100%; } .jqbox_innerhtml { width: 500px; height: 200px; margin: 5% auto; padding: 10px; border: 5px solid #ccc; background-color: #fff; }

This should be inside a horizontally and vertically centered box.

F

Fabien Snauwaert

I just use something like this:

.c-dialogbox {
    --width:  56rem;
    --height: 32rem;

    position: fixed;

    width:  var(--width);
    height: var(--height);
    left:   calc( ( 100% - var(--width) ) / 2 );
    right:  calc( ( 100% - var(--width) ) / 2 );
    top:    calc( ( 100% - var(--height) ) / 2 );
    bottom: calc( ( 100% - var(--height) ) / 2 );
}

It centers the dialog box both horizontally and vertically for me, and I can use different width and height to fit different screen resolutions to make it responsive, with media queries.

Not an option if you still need to provide support for browsers where CSS custom properties or calc() are not supported (check on caniuse.)

A

Alauddin Afif Cassandra

simple, try this

position: fixed;
width: 500px;
height: 300px;
top: calc(50% - 150px);
left: calc(50% - 250px);
background-color: red;

B

BuZZ-dEE

To fix the position use this :

div {
    position: fixed;
    left: 68%;
    transform: translateX(-8%);
}

Please provide an explanation on why your solution would work for the question posted.

L

Loop_Assembly

Center element of a div with the property of

position:fixed

Html and Css code

.jqbox_innerhtml { position: fixed; width:100%; height:100%; display: flex; justify-content: space-around; align-items: center; left: 0; top: 0; width: 100%; height: 100%; border: 5px solid #ccc; background-color: #fff; }

This should be inside a horizontally and vertically centered box.

M

Martin Vahi

One possible answer:

<!DOCTYPE HTML>
<html>
<head>
    <meta charset="UTF-8">
    <title>CSS Center Background Demo</title>
    <style type="text/css">
        body {
            margin: 0;
            padding: 0;
        }

        div.centred_background_stage_1 {
            position: fixed;
            z-index:(-1 );
            top: 45%;
            left: 50%;
        }

        div.centred_background_stage_2 {
            position: relative;
            left: -50%;

            top: -208px;
            /* % does not work.
               According to the
               http://reeddesign.co.uk/test/points-pixels.html
               6pt is about 8px

               In the case of this demo the background
               text consists of three lines with
               font size 80pt.

               3 lines (with space between the lines)
               times 80pt is about
               ~3*(1.3)*80pt*(8px/6pt)~ 416px

               50% from the 416px = 208px
             */

            text-align: left;
            vertical-align: top;
        }

        #bells_and_wistles_for_the_demo {
            font-family: monospace;
            font-size: 80pt;
            font-weight: bold;
            color: #E0E0E0;
        }

        div.centred_background_foreground {
            z-index: 1;
            position: relative;
        }
    </style>
</head>
<body>
<div class="centred_background_stage_1">
    <div class="centred_background_stage_2">
        <div id="bells_and_wistles_for_the_demo">
            World<br/>
            Wide<br/>
            Web
        </div>
    </div>
</div>
<div class="centred_background_foreground">
    This is a demo for <br/>
    <a href="http://stackoverflow.com/questions/2005954/center-element-with-positionfixed">
        http://stackoverflow.com/questions/2005954/center-element-with-positionfixed
    </a>
    <br/><br/>
    <a href="http://www.starwreck.com/" style="border: 0px;">
        <img src="./star_wreck_in_the_perkinnintg.jpg"
             style="opacity:0.1;"/>
    </a>
    <br/>
</div>
</body>
</html>

This does seem to work, although it requires you to already know the width and height of the element.

R

Robert Ross

Try using this for horizontal elements that won't center correctly.

width: calc (width: 100% - width whatever else is off centering it)

For example if your side navigation bar is 200px:

width: calc(100% - 200px);

M

Mosaaleb

This works wonderfully when you don't know the size of the thing you are centering, and you want it centered in all screen sizes:

.modal {
  position: fixed;
  width: 90%;
  height: 90%;
  top: 5%;           /* (100 - height) / 2 */
  left: 5%;          /* (100 - width) / 2 */
}

g

gmonster1st

What I use is simple. For example I have a nav bar that is position : fixed so I adjust it to leave a small space to the edges like this.

nav {
right: 1%;
width: 98%;
position: fixed;
margin: auto;
padding: 0;
}

The idea is to take the remainder percentage of the width "in this case 2%" and use the half of it.

O

O-9

Had this problem so I concluded that using a (invisible) container is the best option (based on answer @Romulus Urakagi Ts'ai). To make it with flexbox:

.zoom-alert {
  position: fixed;
  justify-content: center;
  display: flex;
  bottom: 24px;
  right: 0;
  left: 0;
  z-index: 100000;
  width: 100%;

  &__alert {
    flex: 0 0 500px;
    padding: 24px;
    background-color: rgba(212, 193, 105, 0.9);
    border: 1px solid rgb(80, 87, 23);
    border-radius: 10px;
  }
}

(the syntax is SCSS but can be easily modified to pure CSS)

https://i.stack.imgur.com/8wJ8E.jpg

D

David Minaya

Another simple solution is to set the width of the element to fit-content and set the left and right to 0px;

width: fit-content;
position: fixed;
left: 0px;
right: 0px;

This is useful if you don't know the width of the element.

A

Andrew Barber

The only foolproof solution is to use table align=center as in:

<table align=center><tr><td>
<div>
...
</div>
</td></tr></table>

I cannot believe people all over the world wasting these copious amount to silly time to solve such a fundamental problem as centering a div. css solution does not work for all browsers, jquery solution is a software computational solution and is not an option for other reasons.

I have wasted too much time repeatedly to avoid using table, but experience tell me to stop fighting it. Use table for centering div. Works all the time in all browsers! Never worry any more.

This doesn't answer the question at all. There's no non-CSS equivalent to position:fixed.

Center a position:fixed element

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