Font Size Matters

If you want people to actually read the content on your web site, what font size should you use? How I long for a guideline for minimum font size for both usability and accessibility.

Font Size and Accessibility

The good folks at WebAIM have added an alert to the WAVE for any font rendered at 9px or below. They have observed that it becomes more difficult to read small text below 10px, particularly if you have a visual disability.

Font Size and Readability

Julia Kulla-Mader has studied the readability and legibility of fonts and posted her research at In Search of the Perfect Font. Her conclusion:

* Use an 11 to 14 point font regardless of your audience.
* Pay as much attention to font color as you pay to font size.
* Use scalable fonts.

Font Size and Usability and Aging

Clara Sibley has gathered valuable data on usability and aging. It is not surprise to see that research has shown 8-9 point font sizes (and even 10 point) are too small for the elderly.

Nayak et al (2006) examined the effect of font size and design attributes on comprehension. One hundred and five seniors ranging from 58 to 90 years of age participated in the study. Findings showed that 33% of the participants found 8-9 point font size too small with an additional 22% finding 10-point text too small.

Arc90 Readability Tool

When I’m on a destination page and really want to read it, I often reach for my Readability Bookmarklet. After clicking the magic “Readability” button, I sigh in relief and then dive into the juicy content with my eyes and my brain fully engaged.

So, when you want to read, I recommend Readability aka The Peace and Quiet Button).

What Do You Think?

If you were the god of the internet and could set a minimum font size standard (for text that is intended to be read)…what would you do?

Me…I think, if you set your rendered font size below 10 point, you really don’t want me to read it.


  1. Glenda, a lot of sites use percentages for the main text, and sometimes those percentages can get awfully small. For example, the running text might be 65 percent of normal, and the headings reach 100 percent at h3. Do you consider that to be the same problem?

  2. I’ve found I really can’t get by without Firefox’s NoSquint plug-in. On at least 75% of the web sites I visit the first thing I end up doing is pressing command-+ at least once.

    I’m kind of wondering what to do about the finding that senior adults do best with dark colors on white, since I’ve read elsewhere that dyslexics find it easier to read text with low contrast.

  3. I used to use Readibility but have switched to a similar bookmarklet called Readable, which seems to work better. Also, the latest version of Firefox remembers your zoom preferences for a site automatically now, without having to add-on No Squint. I had to enlarge this page to read it in Firefox, but the next time I come back, it will automatically be the size I want.

  4. There are guidelines to be found about what base font sizes are ideal, but these are always to be considered within a time frame. The article referred above, mentioning an ideal size of between 11px and 14px, is not dated and I suspect it to be not very recent. As screen sizes become larger and screen resolutions higher, we should keep track of legibility and adjust our ideal size accordingly. I find the approach of interesting: they compare text in print (fixed) with text on screen (ever changing) when read at different distances. Considering the screen resolution of modern screens, they currently tend to use a base font size of 16px.

  5. @Glenda: You’re welcome! Good to see it can be of use to you and the team. And thanks for fixing the link in my comment.

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