Adjust text font, including size and spacing (leading and kerning)

Adjust the size and style of font on a page, along with the spacing between the letters, words, or between lines (leading and kerning).

Discussion by Disabilities (Benefits & Preferred Behaviors)

Low Vision

Adjustable fonts and spacing allow the user to customize text to the size and shape that is easiest to see and understand.

Cognitive, Language, Learning Disabilities & Low Literacy

Adjusting spacing between letters, words, or lines may make text easier to read and understand for people with cognitive impairments.

Existing Products

Please note that these products are not necessarily endorsed by RtF, but represent the range of available options.

Open Source and free

These products are free and their source code may be modified with few restrictions.

Free, not necessarily open source

These products are free to use, but may have strict restrictions on viewing and modifying source code.

Commercial, no free trial

These products must be purchased to be used, and did not offer free trials at the time of posting.

Related Research and Papers

Learn more about digital literacy and digital skills.

Learn more about learning disabilities and how they affect an individual’s life also beyond academics.

Learn more about cognitive disabilities, medical conditions and examples of what people with intellectual or cognitive deficits experience in everyday life.

Learn more about low vision, its causes, types and impact on everyday life.

The development of an PDF reader that is typographically oriented and has features that allow users to change the visual presentation of the text including enlargement, reflow, text search, and other accessible features without loss of information.


by CyrusRoshan

a Google Chrome extension that helps readability for people with dyslexia


by Projectbird

Helperbird is an extension that overrides all fonts on web page with the award winning OpenDyslexic font and changes the page to be more easily read. You can switch it on and off at any time. Helping people with dyslexia.