Web filtering is a strong line of defence which can help protect users from malicious websites and malware. With more and more staff working on the go, having protection that goes with them when they leave the office is more important than ever.

How does web filtering work?

Web filtering commonly works as a DNS (Domain Name Service) with additional filtering. As with the linked article, the best way to explain DNS is that it works as a phone or address book. You type google.com into your browser, DNS looks up the address of the website and directs your browser to it. This works the same way as someone looking up the phone number for your business so they can call and speak to you.

With web filtering, additional protection is put into place so that if you do click on a link to a malicious website the web filtering service will instead direct your browser to a special page warning you of what just happened. When combined with other security protections such as email spam filters this starts to really reduce the risk to your business.

Most commercial filters tend to come with security filtering as well as content filtering (e.g. blocking certain categories of websites). Both will be discussed below.

Web filtering for security

The main bulk of the security features of web filters work from blocklists. These are global lists of web domains and IP addresses that are known to contain malicious content. Sites are scanned and categorised to stay up to date as new malicious websites are created. Many have a feature where if you try to go to a website that isn’t get in their database you cannot enter it until it has been scanned. This can slow down web browsing but ensures that you’re always protected.

Can web filtering protect my remote workers?

Absolutely. Many web filtering services support installing an agent on laptops & mobile devices that allows the service to be used no matter the location. In short, even if they’re sat in a coffee shop on the free wi-fi they’re still protected from that phishing link they just clicked. (The risks of open Wi-Fi and why you and your staff should use a VPN will be discussed in a later blog.)

Web filtering for content

Web filtering can also be used to control access to content on business devices. This could often be due to compliance or policy reasons.

One of the most common policies we see is blocking access to social media on work devices during business hours. Oh no! How does my marketing team do their job? Like the blocklists, curated allow lists can be created to let certain staff access content blocked for others.

Another common usage is to block as much advertising as possible to stop your staff getting bombarded while they’re trying to work.

In branch office scenarios with limited bandwidth for their internet connection, this can provide real value by blocking video streaming services.

Other compliance scenarios

Does your business operate a guest Wi-Fi? In some cases there are legal obligations that aren’t always considered or known by businesses. As these varied laws can become quite complex, it makes sense to reduce the risk to your business as much as possible by filtering the guest wi-fi too so that any guests cannot get up to no good using your connection.


Web filtering is absolutely something we recommend all business to use and many services are available from various providers. If you want our help to get set up, we offer web filtering as a Managed Service using the DNS method.

Hopefully you’ve learned something valuable today. Safe browsing!