Readable font size

The readable font size rule checks whether the text in your app is large enough for users to read comfortably. Font size below a minimum size is hard to read for users with low vision, users with reduced contrast sensitivity, and anyone using the app in poor lighting conditions or while in motion, such as while walking or in a vehicle. Small text size also forces users to magnify the screen, which hides the content around it and can also make certain app features non-functional.

The rule evaluates text elements and editable fields that are visible on screen, aren’t covered by another element, and contain text.

Success criteria

The rule checks for the following potential violations:

• A text element that has a font size set below the minimum size of 14sp.
• An editable field that has a font size set below the minimum size of 14sp.

Equivalent units

If your app declares a font size in a unit other than sp, the rule checks for the following values:

If your text is declared in a unit not listed in the table, then the rule doesn’t evaluate the text.

How to fix

To prevent readable font size violations:

• Set the font size of every text element and editable field to at least 14sp.

Platform-specific fixes

Example

The following screenshot highlights a readable font size violation in an Android app:

Errors

• The TextView that displays Terms and conditions apply has the fontSize set as 12sp, which is below the 14sp recommended minimum.

Fix

• Set the font size of the Terms and conditions apply TextView to 14sp or higher.