Language AI meets first-class service: we're merging with Textshuttle. Learn more

test your readability index (RIX) online.

And improve your readability right away.

Children’s book or dissertation –
how does your text score?

The Supertext RIX calculator lets you know – and gives you tips for a truly super text.

The readability index (RIX) shows how readable your text is. It takes into account the number of words per sentence and the length of the individual words. The shorter the sentences and words, the more readable the text is.

Here’s how it works: upload a file or copy your text directly into the box. Its RIX will be immediately calculated and displayed. We also provide tips to help you make your text more reader-friendly.

  • 100
  • 90
  • 80
  • 70
  • 60
  • 50
  • 40
  • 30
  • 20
  • 10
  • 0

Technical literature



Young adult book