The F-Pattern: Nobody Measured How Much of a Page People Read

Two claims travel together through every article about writing for the web. People scan pages in an F shape. And they read only 20 to 28% of the words.

The first is a real observation that its own authors have since narrowed considerably. The second was never measured by anyone.

Where the F-pattern comes from

Jakob Nielsen (2006), in a Nielsen Norman Group article, reported that “we recorded how 232 users looked at thousands of Web pages” and described a dominant F-shaped scanning pattern.

That is the entire method statement. No statistics, no significance tests, no peer review. The document is published by a usability consultancy.

Kara Pernice (2017), updating it for the same organisation, reports that the famous heatmaps came from “more than 45 people” and that a 2017 follow-up used 47 participants. So the canonical N of 232 is not the N behind the canonical image.

The 2017 update does not retract, and it is more interesting than the original. It narrows the claim to “the content area” and calls the F-pattern “the default pattern when there are no strong cues.” It names five other patterns - layer-cake, spotted, marking, bypassing and commitment. And it reframes the F-pattern as a symptom of bad formatting rather than a law of reading: “Good web formatting reduces the impact of F-scanning.”

No prevalence figures are given for any of the six patterns, in either the 2006 or the 2017 document. Nobody has published how often the F actually occurs.

The statistic that was never measured

This is the part worth carrying away.

Nielsen (2008) wrote: “On the average Web page, users have time to read at most 28% of the words during an average visit; 20% is more likely.”

He attributes it to Weinreich, Obendorf, Herder and Mayer (2008), “Not Quite the Average: An Empirical Study of Web Use,” in ACM Transactions on the Web - a browser-instrumentation study of 25 users, retaining 45,237 page views after cleaning, with data collected in 2005.

That study did not measure words read. It logged dwell time.

The 20-28% figure is an arithmetic conversion of time-on-page into words-read, using an assumed reading speed. A behavioural log with no eye-tracking has been turned into a precise-sounding statistic about reading, and then cited for eighteen years as though someone had counted.

We should be clear about what we did and did not verify. We could not open the Weinreich paper - two routes failed. So we are reporting the figures as Nielsen describes them, and our claim is about the inference, which is visible in his own account of it: he describes a dwell-time study and produces a words-read percentage.

What the peer-reviewed work found

The academic eye-tracking literature does not reproduce a single dominant pattern.

Djamasbi, Siegel and Tullis (2011), at HCI International, found the opposite of an F: “users’ viewing pattern in our study was more scattered than those reported in previous studies, which used pages with a relatively less complex visual hierarchy.”

That is a specific and useful boundary condition. The F appears on simple pages. Complex visual hierarchies produce scattered viewing - which is exactly what the 2017 update independently concluded when it called the F a symptom of poor formatting.

Strzelecki (2020), in Information, systematically reviewed 56 peer-reviewed empirical eye-tracking papers from 2004 to 2019. It reports no single scanning path - users adopt breadth-first or depth-first strategies.

It also delivers a methodological verdict on the field that should temper everything above: roughly half the reviewed studies fell below the recommended 30-participant minimum, samples were predominantly university students, and “few studies replicated prior research.”

That review covers search engines rather than content pages. As far as we could establish, no systematic review of general web-page reading patterns exists. That absence is itself worth stating, given how confidently the F-pattern is taught.

What this leaves you with

Something real is being described. People do scan, they do favour the top and left of a content block in left-to-right scripts, and attention does fall off down the page. Nobody disputes the phenomenon.

But it is not a law, and it is not a target. The organisation that named it now calls it what happens when formatting gives the eye nothing to grab. Designing for the F is designing for failure.

Stop quoting the 20-28% figure. It is a conversion of dwell time, not a measurement of reading, and the study it cites did not report it.

Be sceptical of any web-reading statistic without an N and a method. In this literature the foundational documents are consultancy publications with participant counts and nothing else, and the peer-reviewed studies that do exist are mostly small, mostly students and mostly unreplicated.

The practical implication survives the debunking. If scanning patterns are a symptom of formatting, then headings, short paragraphs and front-loaded sentences are worth using - not because they defeat an F-shaped eye movement, but because they give attention somewhere to land. That is the same conclusion, held for a better reason.

For why interfaces teach people to discard whole regions of a page by shape, see banner blindness. For what happens to comprehension when links interrupt reading, see hyperlinks and comprehension. For reading comprehension by surface, see screen reading vs paper.

Limitations of this article

The founding sources are not peer-reviewed. Both the 2006 and 2017 documents are consultancy publications that report participant counts and no statistics. We have said so rather than treating them as research, and we have not printed any effect from them because none is given.

We could not read the Weinreich paper. Two routes failed. Every figure attributed to it here is read in Nielsen’s secondary account, not in the primary. Our argument concerns the inference he describes, not numbers we have checked. Anyone building on this should obtain the primary text and confirm that no words-read percentage appears in it.

The N discrepancy is unresolved. The 2006 article says 232 users; the 2017 article attributes the famous heatmaps to “more than 45 people.” We report both and cannot reconcile them.

We located only one peer-reviewed study directly contradicting the F-pattern, and it is a conference paper. This article would be stronger with more, and we did not find more.

The systematic review we cite covers search-engine results pages, not content reading. We use it for its methodological findings about the field, not as a review of the F-pattern, which it does not address.

No prevalence data exists for any scanning pattern, so nothing in this article can tell you how often the F occurs.