Downloaded HTML is greater the 500KB
This means that the URL in question has HTML content with a total byte size greater than 500KB.
Why is this important?
It is fairly obvious that if a page has a lot of HTML content, it is slow to load. In some respects, 500KB is an arbitrary threshold that helps to define 'too big', but you could come up with your own threshold if you think this is too small or too large.
To give some context, if you want a URL to load within 5 seconds on a fast 3G connection (~ 1.6 Mbps), you have about 1000KB budget for ALL of your content.
Typically, images, scripts and videos are responsible for significantly more page size than HTML, so if you have a lot of HTML then you have very little 'budget' left for anything else.
What does the Hint check?
This Hint will trigger for any internal URL where the sum of the downloaded HTML is greater than 500KB.
How do you resolve this issue?
You can use 'lots of HTML' as a starting point for understanding why a particular set of pages do not load quickly. It may be the case that you have lots of HTML content on a small number of pages where it is necessary, such as long-form text pages.
However, if the issue is more systematic, you may need to examine if you are creating extra code unnecessarily, e.g.
- Are you using nested tables for layout purposes?
- Are you throwing in more <div>s only to fix layout issues?
- Is there a better and more semantically correct way to do your markup?
Moving beyond spot fixes, you should seek to build pages with a performance budget in mind, for each of the page templates you will require. Check the resource URLs below for inspiration.
