UPDATE January, 2017:

According to Can I use, the user-select is currently supported in all browsers except Internet Explorer 9 and its earlier versions (but sadly still needs a vendor prefix).

These are all of the available correct CSS variations:

.noselect { -webkit-touch-callout: none; /* iOS Safari */ -webkit-user-select: none; /* Safari */ -khtml-user-select: none; /* Konqueror HTML */ -moz-user-select: none; /* Old versions of Firefox */ -ms-user-select: none; /* Internet Explorer/Edge */ user-select: none; /* Non-prefixed version, currently supported by Chrome, Edge, Opera and Firefox */ }

Selectable text.

Unselectable text.

Note that user-select is in standardization process (currently in a W3C working draft). It is not guaranteed to work everywhere and there might be differences in implementation among browsers. Also, browsers can drop support for it in the future.

More information can be found in Mozilla Developer Network documentation.

The values of this attribute are none, text, toggle, element, elements, all and inherit.

In most browsers, this can be achieved using proprietary variations on the CSS user-select property, originally proposed and then abandoned in CSS 3 and now proposed in CSS UI Level 4:

*.unselectable {
   -moz-user-select: none;
   -khtml-user-select: none;
   -webkit-user-select: none;

   /*
     Introduced in Internet Explorer 10.
     See http://ie.microsoft.com/testdrive/HTML5/msUserSelect/
   */
   -ms-user-select: none;
   user-select: none;
}

For Internet Explorer < 10 and Opera < 15, you will need to use the unselectable attribute of the element you wish to be unselectable. You can set this using an attribute in HTML:

<div id="foo" unselectable="on" class="unselectable">...</div>

Sadly this property isn't inherited, meaning you have to put an attribute in the start tag of every element inside the <div>. If this is a problem, you could instead use JavaScript to do this recursively for an element's descendants:

function makeUnselectable(node) {
    if (node.nodeType == 1) {
        node.setAttribute("unselectable", "on");
    }
    var child = node.firstChild;
    while (child) {
        makeUnselectable(child);
        child = child.nextSibling;
    }
}

makeUnselectable(document.getElementById("foo"));

Update 30 April 2014: This tree traversal needs to be rerun whenever a new element is added to the tree, but it seems from a comment by @Han that it is possible to avoid this by adding a mousedown event handler that sets unselectable on the target of the event. See http://jsbin.com/yagekiji/1 for details.

This still doesn't cover all possibilities. While it is impossible to initiate selections in unselectable elements, in some browsers (Internet Explorer and Firefox, for example) it's still impossible to prevent selections that start before and end after the unselectable element without making the whole document unselectable.

Until CSS 3's user-select property becomes available, Gecko-based browsers support the -moz-user-select property you already found. WebKit and Blink-based browsers support the -webkit-user-select property.

This of course is not supported in browsers that do not use the Gecko rendering engine.

There is no "standards" compliant quick-and-easy way to do it; using JavaScript is an option.

The real question is, why do you want users to not be able to highlight and presumably copy and paste certain elements? I have not come across a single time that I wanted to not let users highlight a certain portion of my website. Several of my friends, after spending many hours reading and writing code will use the highlight feature as a way to remember where on the page they were, or providing a marker so that their eyes know where to look next.

The only place I could see this being useful is if you have buttons for forms that should not be copy and pasted if a user copy and pasted the website.

A JavaScript solution for Internet Explorer is:

onselectstart="return false;"

If you want to disable text selection on everything except on <p> elements, you can do this in CSS (watch out for the -moz-none which allows override in sub-elements, which is allowed in other browsers with none):

* {
    -webkit-user-select: none;
    -khtml-user-select: none;
    -moz-user-select: -moz-none;
    -o-user-select: none;
    user-select: none;
}

p {
    -webkit-user-select: text;
    -khtml-user-select: text;
    -moz-user-select: text;
    -o-user-select: text;
    user-select: text;
}

In the solutions in previous answers selection is stopped, but the user still thinks you can select text because the cursor still changes. To keep it static, you'll have to set your CSS cursor:

.noselect { cursor: default; -webkit-touch-callout: none; -webkit-user-select: none; -khtml-user-select: none; -moz-user-select: none; -ms-user-select: none; user-select: none; }

Selectable text.

Unselectable text.

This will make your text totally flat, like it would be in a desktop application.

You can do so in Firefox and Safari (Chrome also?)

::selection { background: transparent; }
::-moz-selection { background: transparent; }

Workaround for WebKit:

/* Disable tap highlighting */
-webkit-tap-highlight-color: rgba(0, 0, 0, 0);

I found it in a CardFlip example.

I like the hybrid CSS + jQuery solution.

To make all elements inside <div class="draggable"></div> unselectable, use this CSS:

.draggable {
    -webkit-user-select: none;
     -khtml-user-select: none;
       -moz-user-select: none;
        -ms-user-select: none;
         -o-user-select: none;
            user-select: none;
}

.draggable input {
    -webkit-user-select: text;
     -khtml-user-select: text;
       -moz-user-select: text;
         -o-user-select: text;
            user-select: text;
 }

And then, if you're using jQuery, add this inside a $(document).ready() block:

if (($.browser.msie && $.browser.version < 10) || $.browser.opera) $('.draggable').find(':not(input)').attr('unselectable', 'on');

I figure you still want any input elements to be interactable, hence the :not() pseudo-selector. You could use '*' instead if you don't care.

Caveat: Internet Explorer 9 may not need this extra jQuery piece, so you may want to add a version check in there.

.hidden:after { content: attr(data-txt); }

It's not the best way, though.

You can use CSS or JavaScript for that.

The JavaScript way is supported in older browsers, like old versions of Internet Explorer as well, but if it's not your case, use the CSS way then:

HTML/JavaScript:

This is the Heading!

And I'm the text, I won't be selected if you select me.

HTML/CSS:

.not-selectable { -webkit-touch-callout: none; -webkit-user-select: none; -khtml-user-select: none; -moz-user-select: none; -ms-user-select: none; user-select: none; }

This is the Heading!

And I'm the text, I won't be selected if you select me.

For Internet Explorer in addition, you need to add pseudo class focus (.ClassName:focus) and outline-style: none.

.ClassName,
.ClassName:focus {
    -webkit-touch-callout: none;
    -webkit-user-select: none;
    -khtml-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
    outline-style: none; /* Internet Explorer  */
}

Try to insert these rows into the CSS and call the "disHighlight" at class property:

.disHighlight {
    user-select: none;
    -webkit-user-select: none;
    -ms-user-select: none;
    -webkit-touch-callout: none;
    -o-user-select: none;
    -moz-user-select: none;
}

A Quick Hack Update

If you use the value none for all the CSS user-select properties (including browser prefixes of it), there is a problem which can be still occurred by this.

.div {
    -webkit-user-select: none; /* Chrome all / Safari all */
    -moz-user-select: none;    /* Firefox all             */
    -ms-user-select: none;     /* Internet Explorer  10+  */
     user-select: none;        /* Likely future           */
}

As CSS-Tricks says, the problem is:

WebKit still allows the text to be copied, if you select elements around it.

You can also use the below one to enforce that an entire element gets selected which means if you click on an element, all the text wrapped in that element will get selected. For this all you have to do is changing the value none to all.

.force-select {
    -webkit-user-select: all;  /* Chrome 49+     */
    -moz-user-select: all;     /* Firefox 43+    */
    -ms-user-select: all;      /* No support yet */
    user-select: all;          /* Likely future  */
}

With SASS (SCSS syntax)

You can do this with a mixin:

// Disable selection
@mixin disable-selection {
    -webkit-touch-callout: none; /* iOS Safari */
    -webkit-user-select: none;   /* Safari */
    -khtml-user-select: none;    /* Konqueror HTML */
    -moz-user-select: none;      /* Firefox */
    -ms-user-select: none;       /* Internet Explorer/Edge */
    user-select: none;           /* Non-prefixed version, currently supported by Chrome and Opera */
}

// No selectable element
.no-selectable {
    @include disable-selection;
}

In an HTML tag:

<div class="no-selectable">TRY TO HIGHLIGHT. YOU CANNOT!</div>

Try it in this CodePen.

If you are using an autoprefixer you can remove other prefixes.

Browser compatibility here.

For those who have trouble achieving the same in the Android browser with the touch event, use:

html, body {
    -webkit-touch-callout: none;
    -webkit-user-select: none;
    -webkit-tap-highlight-color: rgba(0, 0, 0, 0);
    -webkit-tap-highlight-color: transparent;
}

If you are using Less and Bootstrap you could write:

.user-select(none);

-webkit-user-select: none;
-khtml-user-select: none;
-moz-user-select: none;
-o-user-select: none;
user-select: none;

*.unselectable {
   -moz-user-select: -moz-none;
   -khtml-user-select: none;
   -webkit-user-select: none;
   user-select: none;
}

<div id="foo" unselectable="on" class="unselectable">...</div>

function makeUnselectable(node) {
    if (node.nodeType == 1) {
        node.unselectable = true;
    }
    var child = node.firstChild;
    while (child) {
        makeUnselectable(child);
        child = child.nextSibling;
    }
}

makeUnselectable(document.getElementById("foo"));

-webkit-user-select: none;
-moz-user-select: none;

onselectstart="return false;"

::selection { 
    background: transparent; 
}

::-moz-selection { 
    background: transparent; 
}

* {
    -webkit-user-select: none;
    -khtml-user-select: none;
    -moz-user-select: -moz-none;
    -o-user-select: none;
    user-select: none;
}

p {
    -webkit-user-select: text;
    -khtml-user-select: text;
    -moz-user-select: text;
    -o-user-select: text;
    user-select: text;
}

<div class="draggable"></div>

.draggable {
    -webkit-user-select: none;
    -khtml-user-select: none;
    -moz-user-select: none;
    -o-user-select: none;
    user-select: none;
}

.draggable input {
    -webkit-user-select: text;
    -khtml-user-select: text;
    -moz-user-select: text;
    -o-user-select: text;
    user-select: text;
 }

if ($.browser.msie)
    $('.draggable').find(':not(input)').attr('unselectable', 'on');

Aside from the Mozilla-only property, no, there is no way to disable text selection with just standard CSS (as of now).

If you notice, Stack Overflow doesn't disable text selection for their navigation buttons, and I would recommend against doing so in most cases, since it modifies normal selection behavior and makes it conflict with a user's expectations.

This works in some browsers:

::selection{ background-color: transparent;}
::moz-selection{ background-color: transparent;}
::webkit-selection{ background-color: transparent;}

Simply add your desired elements/ids in front of the selectors separated by commas without spaces, like so:

h1::selection,h2::selection,h3::selection,p::selection{ background-color: transparent;}
h1::moz-selection,h2::moz-selection,h3::moz-selection,p::moz-selection{ background-color: transparent;}
h1::webkit-selection,h2::webkit-selection,h3::webkit-selection,p::webkit-selection{ background-color: transparent;}

The other answers are better; this should probably be seen as a last resort/catchall.

Suppose there are two divs like this:

.second { cursor: default; user-select: none; -webkit-user-select: none; /* Chrome/Safari/Opera */ -moz-user-select: none; /* Firefox */ -ms-user-select: none; /* Internet Explorer/Edge */ -webkit-touch-callout: none; /* iOS Safari */ }

Set cursor to default so that it will give a unselectable feel to the user.

Prefix need to be used to support it in all browsers. Without a prefix this may not work in all the answers.

This will be useful if color selection is also not needed:

::-moz-selection { background:none; color:none; }
::selection { background:none; color:none; }

...all other browser fixes. It will work in Internet Explorer 9 or later.

Add this to the first div in which you want to disable the selection for text:

onmousedown='return false;' 
onselectstart='return false;'

NOTE:

The correct answer is correct in that it prevents you from being able to select the text. However, it does not prevent you from being able to copy the text, as I'll show with the next couple of screenshots (as of 7th Nov 2014).

https://i.stack.imgur.com/gcKTY.png

https://i.stack.imgur.com/xwPld.png

https://i.stack.imgur.com/Ex6UH.png

As you can see, we were unable to select the numbers, but we were able to copy them.

Tested on: Ubuntu, Google Chrome 38.0.2125.111.

It is easily done with:

-webkit-user-select: none;
-moz-user-select: none;
-ms-user-select: none;
-o-user-select: none;
user-select: none;

Alternatively:

Let's say you have a <h1 id="example">Hello, World!</h1>. You will have to remove the innerHTML of that h1, in this case Hello, World. Then you will have to go to CSS and do this:

#example::before // You can of course use **::after** as well.
{
    content: 'Hello, World!'; // Both single-quotes and double-quotes can be used here.

    display: block; // To make sure it works fine in every browser.
}

Now it simply thinks it is a block-element, and not text.

To get the result I needed, I found I had to use both ::selection and user-select

input.no-select:focus {
    -webkit-touch-callout: none;
    -webkit-user-select: none;
    -khtml-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
}

input.no-select::selection {
    background: transparent;
}

input.no-select::-moz-selection {
    background: transparent;
}

This is not CSS, but it is worth a mention:

jQuery UI Disable Selection:

$("your.selector").disableSelection();

Check my solution without JavaScript:

jsFiddle

li:hover { background-color: silver; } #id1:before { content: "File"; } #id2:before { content: "Edit"; } #id3:before { content: "View"; }

Popup menu with my technique applied: http://jsfiddle.net/y4Lac/2/

Though this pseudo-element was in drafts of CSS Selectors Level 3, it was removed during the Candidate Recommendation phase, as it appeared that its behavior was under-specified, especially with nested elements, and interoperability wasn't achieved.

It's being discussed in How ::selection works on nested elements.

Despite it is being implemented in browsers, you can make an illusion of text not being selected by using the same color and background color on selection as of the tab design (in your case).

Normal CSS Design

p { color: white;  background: black; }

On selection

p::-moz-selection { color: white;  background: black; }
p::selection      { color: white;  background: black; }

Disallowing users to select the text will raise usability issues.

I have learned from the CSS-Tricks website.

user-select: none;

And this also:

::selection {
    background-color: transparent;
}

::moz-selection {
    background-color: transparent;
}

::webkit-selection {
    background-color: transparent;
}