Lexend — A Spacing-Based Open Font Family for Reading Fluency, Released on Google Fonts, With Contested Evidence

Dr. Bonnie Shaver-Troup began Lexend in 2004, commissioning type designer Linnea Lundquist; it launched on Google Fonts in August 2019 after Google Fonts funded Thomas Jockin to digitise it as a variable font. It comes in seven width families (Deca to Zetta), with nine weights added in 2021. The design premise is that tight letter spacing causes crowding and masking problems for readers.
The evidence is mixed and mostly creator-led: Shaver-Troup's doctoral work tested font spacing with second graders, and secondary sources report small positive results, but Google's own article gives no sample sizes or quantified results and states that Google does not endorse its claims. Independent research cautions against assuming typeface fixes reading difficulty: a peer-reviewed study found the Dyslexie font did not benefit reading in children with or without dyslexia, and systematic reviews have found no robust evidence for dyslexia-specific fonts.
Practical reading: free and low-cost to offer as a user-selectable option, but not a substitute for evidence-based reading instruction.

Read the full analysis: https://design.google/library/lexend-readability