[marksbrown]

Unfortunately the internet has been corrupted by JavaScript. A website is rarely loading a single site anymore. Try noscript and you'll quickly see that, even a trivial website loads dozens of dependencies. Dependencies that shift over time.

Reality is whitelisting can't work as you'll simply break websites. This has been my experience at several schools now. Websites may or may not load. And even if they do, they rarely work properly.

Irony is, students are clever enough to realise you can use translate websites to load anything with translation from English to English. No blocking at all!

[cwoolfe]

There are plenty of companies successfully doing allow-list only filters. At home for focus: https://gertrude.app/ At work for security: https://adamnet.works/

[marksbrown]

Sure but here in the UK schools will use what is cheapest, free or part of a wider package of software already used. RM web filtering or smoothwall make me want to bash my skull against a wall at times. Finally School IT staff are not judged on their ability to manage a web filter well. Safeguarding is (rightly) the primary concern and so if an existing solution can be said to block the more egregious parts of the internet, it's irrelevant if it blocks the useful parts too.