Every web page is made up of many separate files: the HTML, CSS for styling, JavaScript for interaction, images, fonts and sometimes video. Together, all those files determine how much data a visitor has to download to see your page. The more data, the longer it takes.
What are good page sizes?
- Under 500 KB: light. Loads super fast, even on mobile with a weak 4G signal.
- 500 KB to 1.5 MB: normal. Fine for most sites.
- 1.5 MB to 3 MB: heavy. Noticeably slow on mobile.
- Over 3 MB: extremely heavy. Visitors on slow connections give up.
What makes pages so big?
The biggest culprits, in order:
- Uncompressed images (by far #1): a single 5 MB photo can ruin your whole page. Often easy to make 80% smaller.
- Autoplaying videos: a 10 MB autoplaying hero video is a killer for people on mobile data.
- Too many external scripts: every tracking pixel, chat widget and embedded video adds weight.
- Heavy fonts: loading 8 different font variants instead of 2.
- Unnecessary JavaScript: plugins you barely use but that still load on every page.
What can you do today?
Go to PageSpeed Insights, paste in your URL and scroll to 'Total page size' or 'Total byte weight'. You will see right away how heavy your page is and which files contribute the most.
The quickest win: if the biggest files are images, compress them with squoosh.app or TinyPNG. Going from 3 MB to 300 KB is normal, with no visible loss in quality.