This is quite a complex thing to answer, but there is a place you can go quickly for a test yourself. It’s FREE, takes about a minute or two, and will tell you if you have good or bad areas of your website.
Visit https://www.gtmetrix.com and submit your website address and click the Analyse button. It will give you various reasons. Here are a few explanations of each section on the result.
Page Speed Score: The higher the better here! It’s essentially the score Google gives you. Most decent sites are within 65-95%. In the upper 90s is where you want to be. If you are below 50%, it’s not good. If below 30%, it’s bad!!
YSlow Score: this is more of how Google interprets your page. Again, the higher the better.
Fully Loaded Time: this is what it says – how long it took to load your page. 1-5s is ok. 10+ is considered slow… and there must be a reason.
Total Page Size: Again, it is what is says. Most websites (particularly the homepage) tends to be between 800kb and 3mb. We have commerce sites in the 2.2-2.9mb range. Anything over 5MB is high. Sadly we have seen 60mb+ websites. This is really very wrong.
Then there is a long list of entries, from Minifying to Image Resizing.
Some of the most common errors are these:
Server Scaled Images: If an image is uploaded as is 1000px wide, but you are only ever showing that full scale image at 200px wide, you are scaling it down, but the user is still loading up 1000px wide image. This is Server Scaling and is wrong. Either your website should be serving up an image that is already resized, or you need to resize it.
Enable GZip Compression: this is down to your host, but also your website platform. This helps such a huge amount with website. More info on this can be found here.
There is a lot involved in this, but a decent website designer will know how to improve on all this. Here is an example of a very poor result (tho we have seen worse).
We have seen a 0% page score recently too.
Below are actually our results as of early 2019.
Very few websites will have a 100% page score. Those with very little on their homepage, with little styling.