I have an image gallery that is done except for one problem. The scrolling for the gallery page is fairly laggy and slow. I thought at first it was just this computer or browser, but It does not act slow on facebook galleries which have 10x the images.
There should be no more javascript executing after the page is loaded so I can’t imagine that it is my jQuery that is causing the problem, but it could be. Is there a way to tell using Google’s developer tool inspector or Firefox firebug if there is javascript executing at any time? I set breakpoints and run through the code and eventually it stops and I can’t step into any more functions. Therefore making me think its not jQuery.
Checking the network log, I am only pulling in 2.37MB of images and assets (this is after i clear the cache, so every image is loaded brand new), so I do not think its purely image size.
Lastly, I even checked my task manager CPU and memory usage and it doesn’t spike when I’m on that page so I don’t think its any kind of infinite loop or memory problem.
Heres the page that has the laggy scrolling: Gallery
EDIT2: You could try implementing image sprites but I really wouldn’t recommend it for this situation.
http://www.w3schools.com/css/css_image_sprites.asp
Or you could increase the image optimization for each image with Photoshop.(Would recommend doing that, if you haven’t already.)… or an online image optimizer like http://kraken.io/
EDIT: You could probably increase the speed greatly by making sure all your Javascript is referenced as an external file, remove the embeded javascript you have. Move all the javascript from the very top where you have it to right before…
And if possible combine all your javascript files into as few as possible and minify them.
Some possible improvements from … http://analyze.websiteoptimization.com/
Analysis and Recommendations
TOTAL_HTML – Congratulations, the total number of HTML files on this page (including the main HTML file) is 1 which most browsers can multithread. Minimizing HTTP requests is key for web site optimization.
TOTAL_OBJECTS – Warning! The total number of objects on this page is 41 which by their number will dominate web page delay. Consider reducing this to a more reasonable number. Above 20 objects per page the overhead from dealing with the actual objects (description time and wait time) accounts for more than 80% of whole page latency. See Figure II-3: Relative distribution of latency components showing that object overhead dominates web page latency in Website Optimization Secrets for more details on how object overhead dominates web page latency. Combine, refine, and optimize your external objects. Replace graphic rollovers with CSS rollovers to speed display and minimize HTTP requests. Consider using CSS sprites to help consolidate decorative images. Using CSS techniques such as colored backgrounds, borders, or spacing instead of graphic techniques can reduce HTTP requests. Replace graphic text headers with CSS text headers to further reduce HTTP requests. Finally, consider optimizing parallel downloads by using different hostnames or a CDN to reduce object overhead.
TOTAL_IMAGES – Warning! The total number of images on this page is 32 , consider reducing this to a more reasonable number. Recommend combining, replacing, and optimizing your graphics. Replace graphic rollover menus with CSS rollover menus to speed display and minimize HTTP requests. Consider using CSS sprites to help consolidate decorative images. Use CSS techniques such as colored backgrounds, borders, or spacing instead of graphic techniques to reduce HTTP requests. Replace graphic text headers with CSS text headers to further reduce HTTP requests. Finally, consider optimizing parallel downloads by using different hostnames to reduce object overhead.
TOTAL_CSS – Caution. The total number of external CSS files on this page is 3 , consider reducing this to a more reasonable number. Because external CSS files must be in the HEAD of your HTML document, they must load first before any BODY content displays. Although they are cached upon subsequent requests, CSS files slow down the initial display of your page. Combine, refine, and optimize your external CSS files. Ideally you should have one (or even embed CSS for high-traffic pages) on your pages. You can optimize CSS files using shorthand properties, grouping, and then minify and GZIP compress them to reduce their footprint. Remember to place CSS files in the HEAD and JavaScript files at the end of the BODY to enable progressive display.
TOTAL_SIZE – Warning! The total size of this page is 2987624 bytes, which will load in 603.63 seconds on a 56Kbps modem. Consider reducing total page size to less than 100K to achieve sub 20 second response times on 56K connections. Pages over 100K exceed most attention thresholds at 56Kbps, even with feedback. Consider optimizing your site with Website Optimization Secrets, Speed Up Your Site or contacting us about our optimization services.
TOTAL_SCRIPT – Caution. The total number of external script files on this page is 5 , consider reducing this to one or two. Combine, refactor, and minify to optimize your JavaScript files. Ideally you should have one (or even embed scripts for high-traffic pages) on your pages. Consider suturing JavaScript files together at the server to minimize HTTP requests. Placing external JavaScript files at the bottom of your BODY, and CSS files in the HEAD enables progressive display in XHTML web pages.
HTML_SIZE – Congratulations, the total size of this HTML file is 1472 bytes, which less than 50K. Assuming that you specify the HEIGHT and WIDTH of your images, this size allows your HTML to display content in under 10 seconds, the average time users are willing to wait for a page to display without feedback.
IMAGES_SIZE – Warning! The total size of your images is 2900543 bytes, which is over 100K. Consider switch graphic formats to achive smaller file sizes (from JPEG to PNG for example). Finally, substitute CSS techniques for graphics techniques to create colored borders, backgrounds, and spacing.
SCRIPT_SIZE – Warning! The total size of external your scripts is 65770 bytes, which is over 20K. Consider optimizing your JavaScript for size, combining them, and using HTTP compression where appropriate for any scripts placed in the HEAD of your documents. You can substitute CSS menus for JavaScript-based menus to minimize or even eliminate the use of JavaScript.
CSS_SIZE – Caution. The total size of your external CSS is 19839 bytes, which is above 8K and less than 20K. For external files, ideally keep them less than 1160 bytes to fit within one higher-speed TCP-IP packet (or an approximate multiple thereof). Consider optimizing your CSS and eliminating features to reduce this to a more reasonable size.
MULTIM_SIZE – Congratulations, the total size of all your external multimedia files is 0 bytes, which is less than 10K.