The average web page is around 2 megabytes, according to HTTP Archives, a site that tracks the performance of websites and the technologies they use. Of course, you can download 2 megabytes in less than a second over a good 4G mobile connection. But today’s web pages are problematic for people with slow connections or with small bandwidth limits. Not so long ago, a complex game or software resided on a 1.4MB floppy disk.

There are many reasons why today’s web is so bloated, including the ads and tracking scripts that fill so many pages. Another reason is that websites do a lot more than just display text and images. Many sites now look like full-fledged desktop apps.

The new JavaScript framework Slender, created by visual journalist and software developer Rich Harris, aims to make it easier to write smaller, faster interactive websites and applications. Web developer Shawn Wang says he’s downsized his personal website from 187 kilobytes to 9 kilobytes from React to Svelte.

“It was a big ‘wow’ moment,” Wang said. “I wasn’t even trying to optimize the size and it just dropped.”

Frameworks add weight to websites because they traditionally serve as a middle layer between an application’s code and the user’s browser. This means that developers should bundle the entire framework, in addition to their own code, with an application, even if they are not using all of the framework’s features. Wang likens it to a rocket that needs huge tanks of fuel to launch into space.

In the JavaScript State 2019 survey conducted among over 21,000 developers, 88% of respondents who used Svelte were satisfied, which gives it the second highest satisfaction rate of the survey, just behind the satisfaction rate of 89% of React. But only 7.8% of those surveyed had used Svelte and 24.7% had never heard of it. During that time, 80.3% had used React.