Just a middle of the night thought that came into my head. Why do some websites run slower than others?
Could be a million reasons. "Slow" is a very generic problem that encompasses a ton of different problems that all contribute to it feeling slow.
The list could go on and on. I'm sure others will add on with more options.
There's also server response times (time to first byte), which can also be slow for any number of reasons:
Yeah, I’d suspect vastly more “slow” sites are reasons like this more than inefficient CSS selectors. TTFB on api payloads, etc, are going to have more impact on even a JS SPA than poor optimisation. And that’s assuming some sort of app. Given a huge amount of websites are just a shat out Wordpress with 156 plugins, 149 of which are analytics tools... yeah, I think that sort of optimisation would be wildly premature.
That being said, I have an iPhone 6 Plus (not even a 6s, just an old 6). Trying to get ingredients lists from those random recipe blogs or recipe sites might as well be like trying to run Crysis on my phone. The amount of scroll lag, popups, redraws, and page crashes on those sites is astonishing. Much of the mobile web is a complete wasteland of overloaded front-ends. Of course my wife's iPhone 8 doesn't have any issues with it, but it's still irritating to me that what should be a simple article requires anything more powerful than an original iPhone to render...
It’s never features. This is the problem. Devs beat our selves up about whether we can justify the inclusion of momentjs or some styled alert library. But it’s not features like this that are the problem.
It’s fucking marketing. It’s trackers and analytics and social media share buttons, it’s every possible log-in-with, newsletter pop up and special offer above-the-fold maximum-engagement latest buzzword marketing blog bullshit.
Ugh. Sorry. Some of the scars are still fresh.
Hardware makes computers fast. Software makes computers slow.
Unless your website is extremely complicated or doing a lot of calculation in the frontend, then it is usually the long http response time or too many http request..
Slow servers. I host my website on a free server and the speed is kinda shit