In my HTML5 mobile app, I am retrieving 10 images at a time from imgur (the user clicks a button to get more images). When the images are retrieved, I apply some formatting via CSS (mostly to the height and width so that it properly fits the dimensions of an iPhone).
My guess is that one of the reasons why it’s taking so long is because I’m applying formatting to the images once they’re retrieved and then showing these images. Would I be better off saving the images in the state they should be displayed with the right dimensions so I don’t have to apply any CSS to them? Would this help in getting the images to load faster?
Thanks!
According to this post, you should probably be grabbing only six at a time.
Also, open your browser's debugger, go to the NETOWRK tab and watch how long things are actually taking.
Are the images that you are loading actually bigger than the display size? If so, it will load slower not because of the CSS application, but because you are loading unnecessarily big images. You should always re-size the images that you use to the displaying size. You can also change the format and/or compression of the images to make it smaller, thus loading faster.
Related
I am trying to write a chrome plugin so I can use some websites that includes a lot of images I dont care about that are problematic to load seeing as my internet connection is poor.
As such, is it possible to stop loading images but just load white boxes instead, with the exact same size, attributed links etc.? I am a bit unsure where to even start on this, as I tried to just .display = None, but that does not help me loading the website when my connection is bad.
Reason why I want to load something is because if all the images etc just disappear the website layout basically goes down the drain and I can't scroll around on it.
I have an image manager that shows a fixed sized grid of images. The thumbnails are relatively small already so I can't really make them smaller. I implemented lazy loading and using a debounce function to check if the images on in the visible region. This increased the speed of launching my image manager. However, if I scroll while the new batch of images are being loaded, the scrolling becomes very slow. Is there anyway around this or to further optimize loading images?
EDIT:
Is there a way to prevent scrolling while a new batch of images are coming in? Kind of like how Youtube just keeps bouncing when we try to scroll to see more comments while they are still being loaded?
Try not to load all the images at once (which I guess you've implemented with Lazy loading), I'm aware that the users online have a high tendency to scroll fast.
I would suggest, few things here:
First
Implementing the Lazy loading in a correct way is essential. here is a list of few best techniques, make sure which works best for you.
You've mentioned, that the thumbnails are relatively small, however I assume only specifying smaller dimensions is not sufficient, I hope you have covered this ground, Else maintain two folder one for Actual images and another for Thumbnails on your hosting server.
Even though we take utmost care, users upload tons of heavy images on our server, if that is the case, you need to resize the images on client end and then upload on the server, one copy in Actual images and another for Thumbnails
If you are talking about product images, keep the PNGs, Why, because they are far better then BMPs and JPGs. Also you can compress them with online tools like https://tinypng.com/ OR with softwares like https://pngquant.org/
Hope this helps resolve your issue, coz it did to resolve mine.
--N Baua
It turns out the slow scrolling was due to me calling getBoundingClientRect() to find new visible images while there were some images still being loaded. That caused a reflow which bogged everything down.
I changed it to load images in batches so that getBoundingClientRect() isnt called when there are images being loaded.
When on my website large amount of data like picture and gallery slider and data along with animation is being loaded it causes the scrolling of the page slow. when I try to scroll the page through the arrow keys the scrolling becomes almost zero with lags between them.
all the javascript files and css are being loaded from cdn links.
is there any specific reason why it is getting slow scrolling. I have used AngularJS.
This is just a guess, but you need to optimize all your photos for whatever size you are displaying it for because they are likely too large. You can use this link to create your new image files:
http://optimizilla.com/
Using the one time binding with angular and increasing the gallery sliding time and there are many way in which angular can be optimised.
https://www.binpress.com/tutorial/speeding-up-angular-js-with-simple-optimizations/135
It helped in my case
I've been given a design for a commercial affiliate-related website where the homepage has 2500+ images on it. Two directions I'm thinking about to ease the loading of the images is to utilize a lazy image loading script.
I've been messing with the jQuery JAIL (Async Image Loader) script. I have it set so that it loads all the visible images when the page loads. Then after a couple seconds it begins downloading all the rest of the images on the page that are below the fold. This is typically like 2400+ images.
The problem is that when the browser is told to download 2400 images it basically freezes up, or at least freezes up the scrollbar until it's done.
Are there any jQuery image loading scripts that are similar to the JAIL but that allow for some type of throttling? Anything really to help from freezing up the page.
I'm also looking into css sprites but for various technical reasons and time constraints it might not be feasible.
Use this jQuery plugin. Example here
It delays loading of images in long web pages. Images outside of viewport (visible part of web page) wont be loaded before user scrolls to them.
Using Lazy Load on long web pages containing many large images makes the page load faster. Browser will be in ready state after loading visible images. In some cases it can also help to reduce server load.
If the images are small, you might consider combining them into fewer large images and loading them all at once, displaying them all as <div> elements with their background image set. Example:
http://jsfiddle.net/XXRwD/
Are there any differences in performance or load/caching behavior when displaying images in img tags vs divs with image backgrounds?
My example:
I have a site with many overlapping images, some of which I will need to load dynamically with javascript. One issue is that I need to anchor the images to the right of the element, so that I can do a nice wipe-to-right effect. Because of this I was using a div with background image positioned right. Couldn't figure out how to do this with img but since divs are working for me I didn't know if this would matter...
AFAIK, browsers cache images the same whether they're in a DIV or an IMG. In any case, I think this one of those cases where specific performance is defined as an implementation detail internal to each rendering engine (and possibly the browsers built around them). As such, it's both out of our control as designers/developers and subject to change from browser to browser and version to version. In other words, I wouldn't spend too much time worrying about it.
The main performance difference is using background images allows you to use CSS sprites. Having one image contain a large number of images from your page means the user only has to make one request instead of one for each image.
Another difference is with responsive layouts. If you have an element that is only shown at certain screen widths (ie, not on mobile phones), it will still load the image if it is specified in the html (using display:none for instance), but most all browsers now will NOT load the image if is a background-image specified in unused media query-CSS rules. A lot of early responsive layouts got criticized because they still used the same bandwidth as the full size sites.
It is also useful with such designs because you can easily specify different images for different screen sizes. "Retina" displays on tablets and even laptops now won't look their best without 2x res graphics. So... even if you don't do such things now, it is probably a good practice to get into, because you might find yourself needing it soon!
I think by using background-image attribute in the div, the page layout gets loaded first and image present in the divs loaded later after the dom is loaded. so by using background-image the html layout is loaded faster on the web browser.
The only difference I can conceive of it this:
You can't scale images as backgrounds, although you can for img tags. This would open a scenario where background images loaded faster becuase it forces you to have the correct native size as opposed to downloading the entire image and scaling it. However, the converse could be true: given that you didn't care about image quality so much, you could deliver smaller imgs to your page and scale them up.
I'd stick with whatever rendered cleaner (and more consistently -- IE/FF/Chrome/Safari/etc).
Technical differences yes, most notably you can set the width/height of an IMG tag and it will stretch the image, which can be useful in some situations.
The main thing you've got to keep in mind though is the context of the image within the HTML document. If the image is content, say an image in a gallery, I'd use a IMG tag. If it is just part of the interface I might use a div instead.