How to apply CSS to iframe?

Edit: This does not work cross domain unless the appropriate CORS header is set.

There are two different things here: the style of the iframe block and the style of the page embedded in the iframe. You can set the style of the iframe block the usual way:

<iframe name="iframe1" id="iframe1" src="empty.htm" 
        frameborder="0" border="0" cellspacing="0"
        style="border-style: none;width: 100%; height: 120px;"></iframe>

The style of the page embedded in the iframe must be either set by including it in the child page:

<link type="text/css" rel="Stylesheet" href="Style/simple.css" />

Or it can be loaded from the parent page with Javascript:

var cssLink = document.createElement("link");
cssLink.href = "style.css"; 
cssLink.rel = "stylesheet"; 
cssLink.type = "text/css"; 
frames['iframe1'].document.head.appendChild(cssLink);

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I met this issue with Google Calendar. I wanted to style it on a darker background and change font.

Luckily, the URL from the embed code had no restriction on direct access, so by using PHP function file_get_contents it is possible to get the entire content from the page. Instead of calling the Google URL, it is possible to call a php file located on your server, ex. google.php, which will contain the original content with modifications:

$content = file_get_contents('https://www.google.com/calendar/embed?src=%23contacts%40group.v.calendar.google.com&ctz=America/Montreal');

Adding the path to your stylesheet:

$content = str_replace('</head>','<link rel="stylesheet" href="http://www.yourwebsiteurl.com/google.css" /></head>', $content);

(This will place your stylesheet last just before the head end tag.)

Specify the base url form the original url in case css and js are called relatively:

$content = str_replace('</title>','</title><base href="https://www.google.com/calendar/" />', $content);

The final google.php file should look like this:

<?php
$content = file_get_contents('https://www.google.com/calendar/embed?src=%23contacts%40group.v.calendar.google.com&ctz=America/Montreal');
$content = str_replace('</title>','</title><base href="https://www.google.com/calendar/" />', $content);
$content = str_replace('</head>','<link rel="stylesheet" href="http://www.yourwebsiteurl.com/google.css" /></head>', $content);
echo $content;

Then you change the iframe embed code to:

<iframe src="http://www.yourwebsiteurl.com/google.php" style="border: 0" width="800" height="600" frameborder="0" scrolling="no"></iframe>

Good luck!

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If the content of the iframe is not completely under your control or you want to access the content from different pages with different styles you could try manipulating it using JavaScript.

var frm = frames['frame'].document;
var otherhead = frm.getElementsByTagName("head")[0];
var link = frm.createElement("link");
link.setAttribute("rel", "stylesheet");
link.setAttribute("type", "text/css");
link.setAttribute("href", "style.css");
otherhead.appendChild(link);

Note that depending on what browser you use this might only work on pages served from the same domain.

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var $head = $("#eFormIFrame").contents().find("head");

$head.append($("<link/>", {
    rel: "stylesheet",
    href: url,
    type: "text/css"
}));

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Here is how to apply CSS code directly without using <link> to load an extra stylesheet.

var head = jQuery("#iframe").contents().find("head");
var css = '<style type="text/css">' +
          '#banner{display:none}; ' +
          '</style>';
jQuery(head).append(css);

This hides the banner in the iframe page. Thank you for your suggestions!

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If you control the page in the iframe, as hangy said, the easiest approach is to create a shared CSS file with common styles, then just link to it from your html pages.

Otherwise it is unlikely you will be able to dynamically change the style of a page from an external page in your iframe. This is because browsers have tightened the security on cross frame dom scripting due to possible misuse for spoofing and other hacks.

This tutorial may provide you with more information on scripting iframes in general. About cross frame scripting explains the security restrictions from the IE perspective.

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An iframe is universally handled like a different HTML page by most browsers. If you want to apply the same stylesheet to the content of the iframe, just reference it from the pages used in there.

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The above with a little change works:

var cssLink = document.createElement("link") 
cssLink.href = "pFstylesEditor.css"; 
cssLink.rel = "stylesheet"; 
cssLink.type = "text/css"; 

//Instead of this
//frames['frame1'].document.body.appendChild(cssLink);
//Do this

var doc=document.getElementById("edit").contentWindow.document;

//If you are doing any dynamic writing do that first
doc.open();
doc.write(myData);
doc.close();

//Then append child
doc.body.appendChild(cssLink);

Works fine with ff3 and ie8 at least

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The following worked for me.

var iframe = top.frames[name].document;
var css = '' +
          '<style type="text/css">' +
          'body{margin:0;padding:0;background:transparent}' +
          '</style>';
iframe.open();
iframe.write(css);
iframe.close();

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If you want to reuse CSS and JavaScript from the main page maybe you should consider replacing <IFRAME> with a Ajax loaded content. This is more SEO friendly now when search bots are able to execute JavaScript.

This is jQuery example that includes another html page into your document. This is much more SEO friendly than iframe. In order to be sure that the bots are not indexing the included page just add it to disallow in robots.txt

<html>
  <header>
    <script src="/js/jquery.js" type="text/javascript"></script>
  </header>
  <body>
    <div id='include-from-outside'></div>
    <script type='text/javascript'>
      $('#include-from-outside').load('http://example.com/included.html');
    </script> 
  </body>
</html>

You could also include jQuery directly from Google: http://code.google.com/apis/ajaxlibs/documentation/ - this means optional auto-inclusion of newer versions and some significant speed increase. Also, means that you have to trust them for delivering you just the jQuery ;)

---

Expanding on the above jQuery solution to cope with any delays in loading the frame contents.

$('iframe').each(function(){
    function injectCSS(){
        $iframe.contents().find('head').append(
            $('<link/>', { rel: 'stylesheet', href: 'iframe.css', type: 'text/css' })
        );
    }

    var $iframe = $(this);
    $iframe.on('load', injectCSS);
    injectCSS();
});

---

use can try this:

$('iframe').load( function() {
     $('iframe').contents().find("head")
     .append($("<style type='text/css'>  .my-class{display:none;}  </style>"));
  });

---

My compact version:

<script type="text/javascript">
$(window).load(function () {
    var frame = $('iframe').get(0);
    if (frame != null) {
        var frmHead = $(frame).contents().find('head');
        if (frmHead != null) {
            frmHead.append($('style, link[rel=stylesheet]').clone()); // clone existing css link
            //frmHead.append($("<link/>", { rel: "stylesheet", href: "/styles/style.css", type: "text/css" })); // or create css link yourself
        }
    }   
});
</script>

However, sometimes the iframe is not ready on window loaded, so there is a need of using a timer.

Ready-to-use code (with timer):

<script type="text/javascript">
var frameListener;
$(window).load(function () {
    frameListener = setInterval("frameLoaded()", 50);
});
function frameLoaded() {
    var frame = $('iframe').get(0);
    if (frame != null) {
        var frmHead = $(frame).contents().find('head');
        if (frmHead != null) {
            clearInterval(frameListener); // stop the listener
            frmHead.append($('style, link[rel=stylesheet]').clone()); // clone existing css link
            //frmHead.append($("<link/>", { rel: "stylesheet", href: "/styles/style.css", type: "text/css" })); // or create css link yourself
        }
    }
}
</script>

...and jQuery link:

<script src="https://ajax.aspnetcdn.com/ajax/jQuery/jquery-1.9.1.min.js" type="text/javascript"></script>

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As many answers are written for the same domains, I'll write how to do this in cross domains.

First, you need to know the Post Message API. We need a messenger to communicate between two windows.

Here's a messenger I created.

/**
 * Creates a messenger between two windows
 *  which have two different domains
 */
class CrossMessenger {

    /**
     * 
     * @param {object} otherWindow - window object of the other
     * @param {string} targetDomain - domain of the other window
     * @param {object} eventHandlers - all the event names and handlers
     */
    constructor(otherWindow, targetDomain, eventHandlers = {}) {
        this.otherWindow = otherWindow;
        this.targetDomain = targetDomain;
        this.eventHandlers = eventHandlers;

        window.addEventListener("message", (e) => this.receive.call(this, e));
    }

    post(event, data) {

        try {
            // data obj should have event name
            var json = JSON.stringify({
                event,
                data
            });
            this.otherWindow.postMessage(json, this.targetDomain);

        } catch (e) {}
    }

    receive(e) {
        var json;
        try {
            json = JSON.parse(e.data ? e.data : "{}");
        } catch (e) {
            return;
        }
        var eventName = json.event,
            data = json.data;

        if (e.origin !== this.targetDomain)
            return;

        if (typeof this.eventHandlers[eventName] === "function") 
            this.eventHandlers[eventName](data);
    }

}

Using this in two windows to communicate can solve your problem.

In the main windows,

var msger = new CrossMessenger(iframe.contentWindow, "https://iframe.s.domain");

var cssContent = Array.prototype.map.call(yourCSSElement.sheet.cssRules, css_text).join('\n');
msger.post("cssContent", {
   css: cssContent
})

Then, receive the event from the Iframe.

In the Iframe:

var msger = new CrossMessenger(window.parent, "https://parent.window.domain", {
    cssContent: (data) => {
        var cssElem = document.createElement("style");
        cssElem.innerHTML = data.css;
        document.head.appendChild(cssElem);
    }
})

See the Complete Javascript and Iframes tutorial for more details.

---

Other answers here seem to use jQuery and CSS links.

This code uses vanilla JavaScript. It creates a new <style> element. It sets the text content of that element to be a string containing the new CSS. And it appends that element directly to the iframe document's head.

var iframe = document.getElementById('the-iframe');
var style = document.createElement('style');
style.textContent =
  '.some-class-name {' +
  '  some-style-name: some-value;' +
  '}' 
;
iframe.contentDocument.head.appendChild(style);

---

When you say "doc.open()" it means you can write whatever HTML tag inside the iframe, so you should write all the basic tags for the HTML page and if you want to have a CSS link in your iframe head just write an iframe with CSS link in it. I give you an example:

doc.open();

doc.write('<!DOCTYPE html><html><head><meta charset="utf-8"/><meta http-quiv="Content-Type" content="text/html; charset=utf-8"/><title>Print Frame</title><link rel="stylesheet" type="text/css" href="/css/print.css"/></head><body><table id="' + gridId + 'Printable' + '" class="print" >' + out + '</table></body></html>');

doc.close();

---

You will not be able to style the contents of the iframe this way. My suggestion would be to use serverside scripting (PHP, ASP, or a Perl script) or find an online service that will convert a feed to JavaScript code. The only other way to do it would be if you can do a serverside include.

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Incase if you have access to iframe page and want a different CSS to apply on it only when you load it via iframe on your page, here I found a solution for these kind of things

this works even if iframe is loading a different domain

check about postMessage()

plan is, send the css to iframe as a message like

iframenode.postMessage('h2{color:red;}','*');

* is to send this message irrespective of what domain it is in iframe

and receive the message in iframe and add the received message(CSS) to that document head.

code to add in iframe page

window.addEventListener('message',function(e){

    if(e.data == 'send_user_details')
    document.head.appendChild('<style>'+e.data+'</style>');

});

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I think the easiest way is to add another div, in the same place as the iframe, then

make its z-index bigger than the iframe container, so you can easly just style your own div. If you need to click on it, just use pointer-events:none on your own div, so the iframe would be working in case you need to click on it ;)

I hope It will help someone ;)

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I found another solution to put the style in the main html like this

<style id="iframestyle">
    html {
        color: white;
        background: black;
    }
</style>
<style>
    html {
        color: initial;
        background: initial;
    }
    iframe {
        border: none;
    }
</style>

and then in iframe do this (see the js onload)

<iframe  onload="iframe.document.head.appendChild(ifstyle)" name="log" src="/upgrading.log"></iframe>

and in js

<script>
    ifstyle = document.getElementById('iframestyle')
    iframe = top.frames["log"];
</script>

It may not be the best solution, and it certainly can be improved, but it is another option if you want to keep a "style" tag in parent window

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Here, There are two things inside the domain

iFrame Section Page Loaded inside the iFrame

So you want to style those two sections as follows,

1. Style for the iFrame Section

It can style using CSS with that respected id or class name. You can just style it in your parent Style sheets also.

<style>
#my_iFrame{
height: 300px;
width: 100%;
position:absolute;
top:0;
left:0;
border: 1px black solid;
}
</style>

<iframe name='iframe1' id="my_iFrame" src="#" cellspacing="0"></iframe>

2. Style the Page Loaded inside the iFrame

This Styles can be loaded from the parent page with the help of Javascript

var cssFile  = document.createElement("link") 
cssFile.rel  = "stylesheet"; 
cssFile.type = "text/css"; 
cssFile.href = "iFramePage.css"; 

then set that CSS file to the respected iFrame section

//to Load in the Body Part
frames['my_iFrame'].document.body.appendChild(cssFile); 
//to Load in the Head Part
frames['my_iFrame'].document.head.appendChild(cssFile);

Here, You can edit the Head Part of the Page inside the iFrame using this way also

var $iFrameHead = $("#my_iFrame").contents().find("head");
$iFrameHead.append(
   $("<link/>",{ 
      rel: "stylesheet", 
      href: urlPath, 
      type: "text/css" }
     ));

---

We can insert style tag into iframe.

<style type="text/css" id="cssID">
.className
{
    background-color: red;
}
</style>

<iframe id="iFrameID"></iframe>

<script type="text/javascript">
    $(function () {
        $("#iFrameID").contents().find("head")[0].appendChild(cssID);
        //Or $("#iFrameID").contents().find("head")[0].appendChild($('#cssID')[0]);
    });
</script>

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var link1 = document.createElement('link'); link1.type = 'text/css'; link1.rel = 'stylesheet'; link1.href = "../../assets/css/normalize.css"; window.frames['richTextField'].document.body.appendChild(link1);

---

There is a wonderful script that replaces a node with an iframe version of itself. CodePen Demo

https://i.stack.imgur.com/NYF5z.png

Usage Examples:

// Single node
var component = document.querySelector('.component');
var iframe = iframify(component);

// Collection of nodes
var components = document.querySelectorAll('.component');
var iframes = Array.prototype.map.call(components, function (component) {
  return iframify(component, {});
});

// With options
var component = document.querySelector('.component');
var iframe = iframify(component, {
  headExtra: '<style>.component { color: red; }</style>',
  metaViewport: '<meta name="viewport" content="width=device-width">'
});

---

As an alternative, you can use CSS-in-JS technology, like below lib:

https://github.com/cssobj/cssobj

It can inject JS object as CSS to iframe, dynamically

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This is just a concept, but don't implement this without security checks and filtering! Otherwise script could hack your site!

Answer: if you control target site, you can setup the receiver script like:

1) set the iframe link with style parameter, like:

http://your_site.com/target.php?color=red

(the last phrase is a{color:red} encoded by urlencode function.

2) set the receiver page target.php like this:

<head>
..........
$col = FILTER_VAR(SANITIZE_STRING, $_GET['color']);
<style>.xyz{color: <?php echo (in_array( $col, ['red','yellow','green'])?  $col : "black") ;?> } </style>
..........

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This is how I'm doing in production. It's worth bearing in mind that if the iframe belongs to other website, it will trigger the CORS error and will not work.

    var $iframe =  document.querySelector(`iframe`);
    var doc = $iframe.contentDocument;

    var style = doc.createElement("style");
    style.textContent = `*{display:none!important;}`;
    doc.head.append(style);

In some cases you may also want to attach a load event to the iframe:

var $iframe =  document.querySelector(`iframe`);

$iframe.addEventListener("load", function() {
    var doc = $iframe.contentDocument;
    var style = doc.createElement("style");
    style.textContent = `*{display:none!important;}`;
    doc.head.append(style);
});

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Well, I have followed these steps:

Div with a class to hold iframe Add iframe to the div. In CSS file,

divClass { width: 500px; height: 500px; }
divClass iframe { width: 100%; height: 100%; }

This works in IE 6. Should work in other browsers, do check!

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