On an average web page, your visitors read about 20% of the words. That's what Jakob Nielsen concluded in 2008, and it raises an awkward question for anyone who has sweated over their website copy. Which 20%?

Where the 20% comes from

Nielsen, of Nielsen Norman Group, published "How Little Do Users Read?" on 5 May 2008. He analysed data from 45,237 page views, drawn from a study by Weinreich and colleagues (Nielsen Norman Group).

His finding was that on an average page, visitors have time to read no more than 28% of the words during an average visit, and 20% is more likely (Nielsen Norman Group).

He also looked at what extra words buy you. For every additional 100 words on a page, people spent about 4.4 more seconds on it. That isn't enough time to read 100 words, so a lot of the extra text simply gets passed over.

What it means for your website

Think about the page you spent the longest writing. Maybe it's your About page, or a services page you rewrote four times. Your visitor is usually on the way to something else, like your prices, your contact form or a photo of your work. They catch a heading, a line and a button, and they move on.

That doesn't mean your words don't matter. It means some words matter far more than others. Headings, the first line of each section, button labels and anything in bold are what get seen. The paragraphs underneath are there for the visitor who's already interested and wants more.

So the job is to put the important bits where a skimming eye lands. If someone reads only your headings, they should still come away knowing what you do and who it's for.

Picture this: someone opens your homepage while waiting for a coffee. They've got a minute, maybe less, before their name is called. What do they see in that minute?

A few things help a page work when it's skimmed:

• Headings that say something. "Branding for bakeries" tells a visitor more than "What we do".

• The important point first in each paragraph, not saved for the end.

• Short paragraphs, so the eye has places to land.

• Buttons that say what happens next, like "Book a call" instead of "Submit".

• Bold used sparingly, on words that matter, so it still stands out.

None of this means dumbing your message down. It means doing the reader the favour of putting the point where they'll see it.

The honest caveats

This data is from 2008 and from desktop browsing. Reading on a phone may work differently, and we don't have comparable numbers for it here, so treat the 20% as a guide rather than a rule for every screen.

It also describes an average visit. Committed readers read more. Someone who chose to read a long article (like this one) will get through far more of it than someone landing on a homepage. So this isn't an argument for cutting every page down to three lines. Your detailed pages can stay detailed. They just need to make sense to someone skimming first, because that's how a new visitor meets them.

One thing to do this week

Open your homepage and read only the headings, the buttons and anything in bold. Skip everything else. Could a stranger tell what you do, who it's for and how to get in touch?

If not, rewrite the headings before you touch a single paragraph. It's a small job, and it changes the part of the page that actually gets read. Then try the same thing on your services page and your About page.

Read only the headings on your homepage. Do they tell the story?