Subtitles designed to improve literacy

Caterpillar Captions is an academically approved font and stylesheet built by world-leading academics, designers and accessibility experts. 

Broadcasters, streamers, educational publishers can now add Literacy Grade Captions ™ to their video content turning screen time into reading time.

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We help broadcasters to create deeper relationships with parents; growing and retaining audiences and helping millions of children to read.

of pupils prefer Caterpillar Captions to regular subtitles

of parents said they would choose a channel with Caterpillar Captions over one without

teachers would recommend that pupils watch with Caterpillar Captions on

of children read better with Caterpillar Captions compared to regular subtitles

The Typeface & Styleguide

Just a few reasons why it’s different… Caterpillar is the world’s first typeface designed specifically to be used on screens to improve children’s literacy. Built from the bottom up with extensive input from global experts, every line, curve and colour has been meticulously tested by thousands of children and educators around the world. 

Colour and contrast

Black on light yellow, high contrast. Studies support the fact that ‘we read best what we read most’ – and that’s dark on light. We use a light yellow background to support dyslexia and avoid distortion.


Align left. Everything we know about reading in the western world means that we should align text left. The visual system is trained to track back to left alignment, in microseconds; deviating from this makes reading harder.

Movement and Motion

Block mode. Text should appear in simultaneous two-line chunks. When reading, we process in whole words and rely on clause context for understanding meaning, rolling animation creates extra work.


Sentence case and regular/bold forms. Never all-capitals: they obstruct recognition by word-shape and it’s just incorrect use of English.


Larger inter-letter, inter-word and inter-line spacing, as well as kerning, to improve accessibility and readability for all.

Background box

Opaque background, fit to lines, bevelled edges. Opaque background boxes provide crisp contrast against which to read letters clearly. Bevelled edges help to minimise intrusion on content and create a child-friendly style.

Asymmetrical shapes

Asymmetrical bowls to make it easy to differentiate between letter shapes, supporting dyslexia.


A high x-height maximises legibility at small sizes, with ascenders extending beyond the capitals height.

Wide proportions

Generous proportions to make letter shapes more easily distinguishable.

Negative space

San serif design, angled spurs, bevelled edges, and large proportions all help to create more negative space in and around letters. This allows breathing room to improve legibility.

Misreads and internal shapes

Every letter has been scrutinised and re-crafted to ensure unique shapes and forms, minimising misreads and confusion, for example between ‘v’ and ‘w’.

Recognisable characters

Thoroughly researched and individually crafted letter shapes, highly recognisable to children all over the world.