I'm designing a responsive site using media queries to change the layout as the viewport size changes.
For mobile, I think it would be beneficial to use a lower resolution image to save on page loading times and bandwidth.
How would I disable the high quality image and replace it with the lower quality image using CSS?
Thank you.
Using the HTML5 picture element, you can specify inline media queries to size your images:
<picture>
<source srcset="sm.png" media="(max-width: 400px)">
<source srcset="mid.png" media="(max-width: 800px)">
<source srcset="lg.png">
<img src="lg.png" alt="MDN">
</picture>
The element will degrade gracefully to show the image tag in browsers that don't support it.
Read more about the picture element on MDN.
Also, a JS polyfill in case the img tag fallback isn't enough!
At the time of this writing, the picture element has virtually no browser support.
So here are two alternatives:
If the image is sourced in the CSS you can prevent it from loading with display: none.
If the image is in the HTML img tag consider that the browser calls images from the src attribute. You can work around this by using the the data attribute instead. Apply data to all images and add src only when you want to load them.
HTML
<img data-src="http://i.imgur.com/60PVLis.png" height="100" width="100" alt="">
JS
$(document).ready(function() {
$(this).find('img').each(function() {
$(this).attr("src", $(this).data("src"));
});
});
you can develop your css spreadsheet file by adding display none for large images in mobile view, the new mobile browsers wont load large images if they contain display:none in css, allowing the page to load faster and also adding display non for small images in desktop view will do the same .
It's simple - create another image with less resolution, and put it with media queries.
Media Queries can help you hide and show elements based on screen resolution and media type.
A great resource would be this article about media queries on CSSTricks which covers different devices, platforms and res
Related
We have a product details page on our website and it has a preview of a large image of the product. The problem is because of it being too large and hi-res, it takes time to load and render on our page. Now I've read about something called image upscaling or from what I've understood it works a bit more like lazyloading the images. So the concept is they generate a very small, in terms of file size and image dimension, version of the large image and set it as the initial preview of the image. Then size it up to same as the large image's original dimension. So it is stretched and they blur it out. They wait for the larger image to load then replace the smaller one with it once it is done loading. I've seen this in multiple blogs and news website and it seems like a very good solution. But my concern is, does this affect our page's SEO? If so, is there a way to implement this kind of behavior without hurting our page's SEO?
I understand that you have a problem with optimizing your images. To solve this, I recommend that you apply the following techniques:
Add the srcset attribute to the img element. The srcset attribute extends the functionality of the img element. If the browser does not support the srcset attribute, by default the image file is imported using the src attribute. If the browser supports the srcset attribute, you can specify a list of image sources and conditions (comma-separated) before the request is received. As a result, only those images that match the parameters of the device are downloaded and displayed.
Art direction in the responsive images with the element picture. If you want the images to vary depending on the characteristics of the device (art direction effect), use the element picture. The picture element specifies a declarative solution to provide multiple versions of the same image, depending on the various characteristics of the device: size, resolution, destination, and so on.
<picture>
<source media="(min-width: 800px)" srcset="head.jpg, head-2x.jpg 2x">
<source media="(min-width: 450px)" srcset="head-small.jpg, head-small-2x.jpg 2x">
<img src="head-fb.jpg" srcset="head-fb-2x.jpg 2x" alt="a head carved out of wood">
</picture>
In the above example, if the width of the browser is not less than 800 pixels, the head.jpg or head-2x.jpg format will be used (depending on the screen resolution of the device).If the width of the browser is from 450 to 800 pixels, the formats head-small.jpg or head-small-2x.jpg (also depending on the screen resolution of the device) are applied. If we are talking about a screen width of less than 450 pixels and a device with downward compatibility, the picture element will not be supported. In this case, the browser uses the img element to display the image on the screen (it must be enabled).
Images with relative dimensions. If the final image size is unknown, it is difficult to select the pixel density descriptor for image sources. This, in particular, refers to images that are stretched proportionally to the width of the browser and change their size depending on it. In this case does not indicate the fixed image size and pixel density. Instead, you can determine the size of the image being processed by adding a handle to width. This will allow the browser to automatically calculate the optimal pixel density and select the correct image to load.
<img src="lighthouse-200.jpg" sizes="50vw"
srcset="lighthouse-100.jpg 100w, lighthouse-200.jpg 200w,
lighthouse-400.jpg 400w, lighthouse-800.jpg 800w,
lighthouse-1000.jpg 1000w, lighthouse-1400.jpg 1400w,
lighthouse-1800.jpg 1800w" alt="a lighthouse">
This example shows an image that takes half the width of the viewport (sizes = "50vw" when applying the viewport) and depends on the width of the browser and its ratio of logical and physical pixels. As a result, the browser can select an image that will be displayed correctly in a window of any size.
Please note that images of the JPG-JPEG format have approximately 50% less volume than PNG. Therefore, they are easier and faster to load. To change the image format and resize images, you can use this tool Photo Editor Online. To compress images, you can use this tool - JPEG and PNG compressors.
The best solution is the use of Accelerated Mobile Pages AMP. Please note that in their implementation of the image element is also used the srcset attribute.
Original source ++ Use Cases and Requirements for Standardizing Responsive Images ++ Responsive images of MDN.
You can use for preloading images of the current web page with meta preload, eg: <link rel="preload" href="//examples.com/images/img1.jpg" as="image">
Read more Preload of W3C ++ Preloading content with rel="preload" of Moz.
For SEO I'm going to assume you want to go by googles standards for my answer.
lazy loading will help your bandwidth, not your SEO google will judge your website by full page load time.
I recommend you compress your images and that will be all the difference.
if you have any pictures you can load 20 pics and the have a button saying load more, then lazy load from there.
this would be a big SEO boost as your now loading half your website.
I read about retina ready sites and I get some information like In retina ready sites images, slider,font and other elements are more sharper, more density and high resolution...
My Question is:
How I convert Normal Site to Retina Ready with Images, Fonts and other things...
<img src="image1#2x.jpg" width="660" height="440"/>
Original width: 660px and height: 440
And I already import retina.js
Download RetinaJS from Here
Thanks in Advance
If you want to use high density images, you have to set another attribute : srcset.
In this way, src attribute is usefull for old browsers that don't support srcset attribute. srcset attribute is used by modern browsers that will use it in order to load high density "#2x" image if the screen is ready for it. If the screen is not retina, the browser will automaticly load the low density image "#1x".
<img srcset="image#1x.jpg 1x, image#2x.jpg 2x" src="image#1x.jpg" alt>
You can look at this article from MDN if you need more information about it. There are more attributes that can help you like size.
https://developer.mozilla.org/en-US/docs/Learn/HTML/Multimedia_and_embedding/Responsive_images
Hi I'm trying to make a Quicktime player responsive but I fail on each attempt, don't know if this is possible.
Is there any way to do it with css, or I need any javascript to properly do it?
The container of the player response when I resize the browser but when doing this I only see a part of the video.
The video format is in .mov
I found the solution, it's quite simple. In this link you have all the documentation of the Quicktime player.
You can use javascript with ac_quicktime.js or use a simple embed/object, the embed/object uses a lot ot attributes that you can find on the link that i put previously.
Here's an example to embed a video that fits to the 100% height and width o the container.
<embed src="#urlOfTheVideo" HEIGHT="100%" WIDTH="100%" TYPE="video/quicktime" PLUGINSPAGE="http://www.apple.com/quicktime/download/" AUTOPLAY="true" CONTROLLER="true" SCALE = "Aspect" />
The most important attribute here are the width and height, but to maintain the aspect of the video it's very important to add the attribute SCALE="Aspect" you can also use ToFit as value which will fit the parent container.
Hope to someone find this usefull
We're currently building a website for mobile devices. Supported operating systems and browsers should be:
Android 4.x (Stock Browser, Google Chrome)
iOS6+ (Safari, Google Chrome)
In order to also support high resolution displays we evaluated various techniques and libraries to automatically replace images with their high-res pendants:
Attempt 1: retina.js
http://retinajs.com/
The first attempt was to use a normal <img> Tag like this: <img src="foo.png"> and use retina.js to let it automatically replace the src Attribute with the name of the retina image (foo#2x.png). This works but has 2 downsides: First, it will create unwanted overhead because both, the original as well as the retina image, would be loaded and second, if there is no retina image available it will cause lots of 404 errors on server log which we do not want.
Attempt 2: picturefill.js
https://github.com/scottjehl/picturefill
This framework uses some weird html markup based on <span> elements. For me it looks like as if the author tried to mimic the proposed <picture> element which is not a standard (yet), see http://picture.responsiveimages.org - I don't like this approach because of the weird markup. For me it doesn't make sense to semantically describe images with spans.
Attempt 3: Replace images via CSS property background-image
I see sometimes people using CSS media queries to detect retina displays and then set a background-image on a div (or similar element) with a higher or lower solution picture. I personally don't like this approach either because it completely discourages creating semantically good markup à la <img src="foo.png">. I can't imagine building a website just with div's and then set all images as background images - This just feels very weird.
Attempt 4: Set images via CSS property content:url(...)
As proposed here Is it possible to set the equivalent of a src attribute of an img tag in CSS? it seems to be possible to overwrite the src Attribute in img Tags via CSS using the property content:url(). Now, here is the plan: We set img tags for each image with a transparent blank 1x1 png referenced in its src attribute, like this: <img id="img56456" src="transp_1x1.png" alt="img description">. Now this is semantically ok and also valid against the W3C validator. Then we load a CSS Stylesheet that sets all the images on the website via Media Queries.
Example:
#img56456{content:url(foo.png)}
#media (-webkit-min-device-pixel-ratio: 2){
#img56456{content:url(foo#2x.png)}
}
Now, this approach works pretty good:
No overhead
Solid markup
Works on the required devices/browsers
SEO for Images is not requirement here
Now, could this approach cause any side effects we didn't think of? I am just asking because I know it works but kinda "feels" weird to set all images via CSS and I also found this comment on this approach on SO Is it possible to set the equivalent of a src attribute of an img tag in CSS?:
"Worth to add that even in browsers that support assigning content to
img, it changes its behavior. The image starts to ignore size
attributes, and in Chrome/Safari it loses the context menu options
like 'Save image'. This is because assigning a content effectively
converts img from empty replaced element to something like
<span><img></span>"
Could this be a problem? (I didn't notice any sizing problems and the context menu is not a requirement)
There are lots of advantages and disadvantages, but one disadvantage is that the image won't be cached. This is more of a problem on mobile devices where internet is generally slower and more expensive for the user (if on a data connection not wifi).
I don't know about those libraries but you could use media-queries, depending on how many images you have, otherwise it would be lots of code variations to write. And have a threshold screen size at which point you use a different file. Only one file is actually loaded, even though you specify both in the media-queries.
The new version of picturefill http://scottjehl.github.io/picturefill/ doesn't rely on <span> any more. Instead it simply uses the official HTML5 srcset attribute and mimics its behavior if the browser doesn't support it, so for me this is the ideal solution after quite a while now.
Using the CSS property content:url(...) was a neat little idea but it made things a little complicated and hackish too.
So, to answer my own question: No, it's a bad idea. Using the new version of picturefill is a way better solution. You can even remove it after a while when newer versions of all major browsers support the srcset attribute and you'll still be standard compliant. http://caniuse.com/#search=srcset
Example:
<img srcset="examples/images/small.jpg, examples/images/medium.jpg 2x" alt="A giant stone face at The Bayon temple in Angkor Thom, Cambodia">
<script src="picturefill.js"></script>
I am trying to create a page where appropriate images to load are determined by javascript, based on browser size. For example:
<img src="image1.jpg" />
javascript would change it to:
<img src="image1_800px.jpg" />
and load the 800px wide image version.
Doing this is not a problem. Problem arises when i try to do the same for browsers without javascript. The basic idea would be to hide images initially and display them with a style in NOSCRIPT tag. So browsers that support javascript will change image urls and make those images visible and browsers that don't support javascript will simply unhide those images by css. The problem is that images with display:none are loaded by browsers. And adding image url into anything but the src attribute is not an option as such image would rely on javascript to set its src.
So are there any ideas if it's possible to make this work?
For instance: i could rewrite image src attributes on domready and hope that browsers don't manage to start loading images from old src, but would that be the case? If so - would it always be the case or would some browsers work differently?
I think what you're looking for is http://adaptive-images.com/ - it uses Javascript to determine image size, but also has a back-up option if the user does not have Javascript enabled that still provides the resized image (with caveats, read the docs).