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Faq Why the Screen Reader font sizing makes the whole text very small/large?
Why the Screen Reader font sizing makes the whole text very small/large?

To correct this, you find the option to change the 'Default character size' under the plugin settings
To match your default text font size you have to increase/decrease the value until you find the natural base font size of your website.
After changing it click the reset font size button in the screen reader or clear browser cookies.

plugins settings

Additionally you can choose to enable the font sizing only when the Screen Reader toolbar is opened, thus leaving unaltered the font size on page loading:

font size settings