PHILADELPHIA (CBS) – Ever feel like the internet is getting slower?

According to data tracked by HTTP Archive, the average time to download a website has increased.

READ MORE: Revitalized Park, Honoring 6-Year-Old Boy Who Died Protecting His Sister, Opens In North Camden

Experts say that’s because the average size of a website is nearly double what it was three years ago.

READ MORE: Pennsylvania Health Officials Seeing Increase In Tick-Borne Diseases

Videos, pictures, embedded tracking tools and increased website security also contribute to slower speeds.

MORE NEWS: 36-Year-Old George Smith, Of New Jersey, Charged In 'Gas N Go' Fuel Spill In Delaware County

Online traffic is also up, thanks to mobile devices such as tablets.