A few versions back, WordPress’ WYSIWYG editor started using the <strong> tag instead of the <b> tag.

And it wasn’t just WordPress – a lot of software quietly made the shift was well.  Dreamweaver, for one.

Why the change?  What’s the difference between the two HTML tags?

As with most arguments of a religious nature, there’s both a short and a long answer to those questions.

Here’s the short answer: Functionally, there’s no difference whatsoever.  Browsers render the tag exactly the same way.

And now, the long answer: But that short answer isn’t quite correct.  While there isn’t a functional difference, there is a semantic difference between “bold” and “strong.”   And it goes like this:

  • In a piece of writing,  ”bold” is a strictly presentational element – that is, when you say “bold,” you are instructing whatever is rendering the text to increase a font-weight.
  • “Strong,” on the other hand, is a structural element.  Strong says nothing about how text should be rendered – instead, it says “in the context of this written piece, this passage should be read/spoken with strong emphasis.”

It may help to think of the situation in terms of a spoken piece, rather than a written piece.  In a spoken piece, if you want a speaker to emphasize a particular passage, you use the term “strong,” not “bold.”  You say, “This line should be spoken strongly!  With strong emphasis!”  Not “Say this line in bold.”

What we’re really talking about here is the separation of presentation and content.   While the topic may seem trivial to many, to others it conjures up feelings as strong (or as bold) as one’s own religious convictions.  And for that reason, I’m going to steer clear.

Keep in mind that these distinctions also apply to the difference between the italicize tag, “<i>”, and the emphasis tag, or “<em>”.

So which one should I use, <strong> or <b>? Technically, “<strong>” is correct when you are trying to emphasize a particular word or passage.  The World Wide Web Consortium (w3c) recommends using <strong>, as it separates the presentation of the content from the content itself.

I suppose one could argue that using “<b>” rather than “<strong>” is correct when you are bolding something solely for presentation’s sake – like a section heading or visual marker of some sort. The W3C would probably disagree, saying that you should instead use a header tag (e.g. <h3>).  The W3C hates <b>, and loves well-structured content.

Still, you won’t find many downsides to using “<b>”.  So unless you’re in a large organization with guidelines on this topic, I’d say to go ahead and use whichever you prefer.

When I’m coding HTML by hand, I don’t like the extra keystrokes it takes to type those extra 5 letters, so I use a simple <b> tag.  When I use WordPress’ WYSIWYG editor, it uses the “<strong>” tag automatically, and I don’t mind one bit.   On this site, like most others, there is no functional difference between “strong” and “bold.”  So for me, (and probably for you, too,) it really doesn’t matter.