Feb 9, 2015

What happened when I increased Font Sizes

What happens when I increased Font Sizes Front
Website font sizes are an important factor in determining if a visitor leaves your website happy or sad. The current study will help you figure out what effect increasing your website's font size will have on the overall quality and quantity of visitors.

One of the most popular articles on codemakit was based on a study which answered a simple question. One which has been asked by numerous webmasters, designers and bloggers worldwide. The question was "What is the best font size?" it could be rephrased as "Which font size would lead to highest user interaction?" or "Which of these should I choose, 12px, 14px, or 16px?"

During the research, I came across several opinions. Some wanted to "Follow your heart!" (I don't know how their websites are read), Some said "The size depends on the type of website" (Which is why I conducted the study). You can still check out the complete study on Type of Fonts, Size of Fonts and Color of Fonts. But, after the study, the result were condensed into simple 4 letters ; 14px.

The preface

Based on the previous study, codemakit changed the default font size from its 12px to 14px. Then the blog was observed for 30 days during which several parameters were monitored closely. The following parameters were studied.

  • Number of Visitors (Page views)
  • Bounce Rates (%)
  • Pages per Session
  • Percentage New Sessions


The Results

The following data was observed from the blog after the change in text size was made.
After the change in font size was made, Several parameters were observed for a period of 17 days.

Changes in Page Views

Regarding the changes in page views. It is abundantly clear that the number of page views increased after the changes were made. A rough estimation points out that the increase in page views were upwards of 35 percentage. Though the direct increase in the number of page views is often attributed to marketing strategies and Search Engine Optimization, the sudden increase in the number of page views can be indirectly caused by an increase in returning visitors and the increase in the number of pages viewed in one session. Those parameter shall be discussed separately later.

The following Graph depicts the changes in the number of page views in the 43 day period. Kindly keep in mind that the changes in the font size were completed on 25th December 2014. The repercussions from it are depicted in the later part of the graph.

Changes in Page Views


Bounce Rate

It was found that the overall bounce rate of the blog decreased. Though bounce rates are never a perfect indicator of a blog's health, they are still a good indicator of what your visitors do when they enter your website. A lower bounce rate would inevitably be better than a higher one. A question arises, Is it possible that the bounce rate was decreasing from before the time the changes were made? 

Though it is possible for a growing and improving blog, one can still find out if the change in the bounce rate was premeditated by the change in font size. Hence we take two different data sets, One from the bounce rates of the blog before changes were made and another, bounce rates at the blog after the changes were made.

Bounce Rate


With the help of excel trend-line function, trend lines were created for both the data sets. It was found that the bounce rate decreased from 87.7% to 86.4%, i.e. a 1.5% decrease. However one look at the data after changes were made would show that the bounce rate decreased from 89.5% to 77.1% i.e. 14% decrease. This proves that increasing the font size decreases bounce rate at a much higher rate than better content quality management practices.

Percentage New Sessions

Percentage New sessions are the total percentage of sessions opened with new users. decreasing this number from 100 would give you the percentage of users which came to the website for more than one time. A higher percentage new sessions might mean that most of your readers are first timers. A lower percentage new sessions would indicate the presence of loyal returning visitors who come back to the blog because of sheer content quality or better marketing practices.

Percentage New Sessions


Percentage new Sessions in the experiment decreased from 90% to 88%. Though the decrease is a meager 2.2 percent, this might indicate an increase in returning visitors as a result of the changes made. Further analysis from data sets created before the experiment and after the experiment said that the % new sessions increased before and after the changes. But the changes led to an initial lowering of the values. In short, the effects of the changes made could not be analysed properly and can be termed inconclusive.

Pages per Session

The pages per session is the number of webpages opened by the user during his visit. The only anomaly observed in the experiment was that the pages per session actually decreased during time. Though the decrease was a meager 0.1 which is a decrease of 6%, a value much higher to be discarded. No logical reason explains this phenomena.

Pages per Session


It is thought that more data for Percentage New Sessions and Pages per Session are required before venturing into an in-depth analysis of the reasoning of the phenomena.

Related Reading

You might want to understand why we chose 14px from our quest to determine the best website Font Sizes.

Are you aware of the best practices for Website Fonts, read this and you will be.

If you have doubts about some of the terms used here, you can check out this bounce rate article on how bounce rates are calculated or this one on how a blog dies.

We also did a similar article where a parameter in the blog was changed and its data was analysed. It actually doubled the number of page views.

This answered,
What happens when I increased Font Sizes MohitChar