A survey of Browser Text Size settings

clickdensity has now been up and running for over 3 months, during which time we've recorded about 20 million visitor sessions from nearly 1,500 websites. With this quantity and variety of data, we thought it would be worthwhile finding and publishing useful generic statistics that are not currently available elsewhere on the web. We'll start with Text Size settings.

Text Size settings

One of the browser properties we detect and store for every session is the user's Text Size setting. Most modern browsers (Internet Explorer, Firefox, Safari, Opera, and so on) allow the user to change this setting, to scale the text on websites up or down. As each browser has a slightly different range of scaling options, we have chosen – for the sake of clarity – to limit the statistics presented here to the Internet Explorer settings of Smallest, Smaller, Medium (the default setting), Larger, and Largest.

As can be seen from the graph below (which we've decided to visualise as a logarithmic bar chart, rather than a pie-chart), about 99.7% of visitors use the (default) Medium text size setting. Roughly 0.1% of visitors choose a text size smaller than Medium, and 0.2% of visitors choose a text size larger than Medium.

A bar chart showing the distribution of Text Size settings, with 99.71% of visitors using Medium.

There is some relationship between Text Size and Screen Resolution. Generally, the difference between the data above (from all screen resolutions) and the same results for specific screen resolutions is very small (less than 1% difference at each Text Size). The one exception to this rule is at 640 x 480, where 84.6% of visitors use the Medium setting and 15% of visitors use the Larger text size setting. However, only about 0.1% of visitors in this data set use 640 x 480, making this a tiny section of the audience.

A bar chart showing the distribution of Text Size settings for visitors with 640 by 480 resolution.  84.61% use Medium, and 15.03% use Larger.

Visitors with very high screen resolutions (1600 x 1200 and above – representing about 2.5% of all visitors), are at least twice as likely to change their text size setting (when compared to users from 800 x 600 up to 1280 x 1024, making up over 90% of all visitors). The percentage of visitors (within each screen resolution group) who increase their Text Size setting is displayed in the following graph:

A bar chart showing the percentage of visitors using increased text size, by screen resolution.  Larger screen resolutions have a higher percentage.

Similarly, the graph below shows how many users within each Screen Resolution group decrease their Text Size setting (to Smaller or Smallest):

A bar chart showing the percentage of visitors using decreased text size, by screen resolution.  Larger screen resolutions have a higher percentage.

Summary

  • The vast majority of visitors (99.7%) use default (Medium) text size settings.
  • Approximately twice as many visitors (0.2%) increase their text size than decrease their text size (0.1%).
  • Users with very low (640 x 480) or very high (larger than 1600 x 1200) screen resolutions are at least twice as likely to change their text size settings (compared to users with resolutions from 800 x 600 to 1280 x 1024).