Why do I sometimes get an error message instead of a web page?

Q  Sometimes, when I try to access websites, my web browser displays a failure message. The browser has added ‘%20’ at some point in the address.

When I try to visit www.computeractive.co.uk, for example, it fails and the web address seems to become computeractive%20.co.uk. How do I get rid of this error?
Ray Jordan

A  We believe this is an error of your own making. Or at least, it’s a mistake that’s not being helped by your browser or internet service provider (ISP).

The ‘%20’ code you cite is hexadecimal notation that equals 32 in the decimal number system. Less cryptically, the number 32 represents the space character – leading us to think that you’re occasionally hitting the space bar as you type in the web addresses.

This kind of common mistake can be handled in several different ways, and will depend both on the browser and your ISP’s settings. In some situations, the browser will simply refuse to accept the erroneous URL and inform the user that it is invalid.

In other situations, though, the browser may accept the faulty URL and pass it on to something known as a DNS server. These translate URLs into the IP addresses (numbers) understood by computers.

For example, you may type www.bbc.co.uk/news to visit the BBC News website but a DNS server will translate this to ‘212.58.246.82’, so that your PC can find it – try typing 212.58.246.82 into your browser’s Address or Location bar and it works just as well.

Some browsers and/or DNS servers are smart enough to strip out erroneous spaces in URLs, so some people never even notice when they make this mistake.

Others will direct such mistyped URLs to a search engine, such as Google, which then usually finds the correct address and displays it at the top of the search-results list.

In your case, though, we think that the browser is allowing the faulty URL to be passed on to the DNS server – which responds with the error you’re seeing.