How to improve website loading speed?

Question

Layout

Good afternoon, I want to increase the speed of loading the site, I know about the main methods. Interested in different approaches to images, how best to do it.
1) Is it worth it for a Ukrainian site where users will be Ukrainians to use free CDNs, which are not available in Ukraine (this is my main remark from gtmetrix.com)?
2) MB worth trying to make subdomains and load images from subdomains, because. I read somewhere that there is a limit on the simultaneous download N-of the number of files from one domain
3) Is it worth it to combine backgrounds (1920px by 600px + -) into Sprites or is it crazy to load such canvases?
Or maybe there are some other interesting options? Thanks in advance!

Answer 1

1. No
2. Yes, but only if there are 20+ images in the content on the page
3. No, you need to combine a lot of small images
To find problems, you need to use the browser
profiler

Answer 2

2. yes
3. no

Or maybe there are some other interesting options?

To get started, run your site through Google PageSpeed ​​and see the recommendations.

Answer 3

http2 include with preloads.
Defer everything you can with lazy loading.
And draw the first screen separately first, asynchronously load everything else.
CDN is possible, but after everything else. Most likely it won't be needed.

Answer 4

limit on simultaneous download of N-number of files from one domain

There are no restrictions. There is only the principle that all downloads from one domain go sequentially. That is, you can separate the photo files into a subdomain, while they will be loaded in parallel with all other files of the js css type.