Is it online, on line or on-line?

These days, when talking of the Internet world, most users will use ‘online’ and this denotes the Internet concept.

Way back, when these words were starting out, many forms were seen in written communications (online, on line and on-line); the difference between them (ie the use of the hyphen) is very important and applies to many other grammatical forms.

It’s now common to use ‘online’, whereas, at first, to say that you were ‘online’ was seen to be like saying that a tennis player is ‘oncourt’ or that a builder is ‘onsite’, rather than saying she/he is ‘on site’. Usually (before it became common to use ‘online’)…

  • Where the phrase is just a factual statement, we used two words.
  • Where the entire phrase is used to further describe something else, we used the hyphen to show this.


  • My PC is now on line, so you can use it. SAME AS This is a policy in the short term.
  • This is an on-line transaction. SAME AS This is a short-term policy.

This solution is then perfectly consistent with all other forms in this grouping:

  • My car is now on site.
  • This is an on-site car park.

However, this has now moved from a hyphenated compound into a closed compound and is: online