A typewriter effect library for React.

Apply the typewriter (or, ahem, "windup") effect to:

  • strings
  • anything you can put in React's children prop!

Use the API to:

  • Control the pacing of your windups
  • Trigger animations, sounds or any effect you can think of!
  • Intelligently handle line breaking in text!

Examples, API docs, and guides can all be found at the docs site!

? Code landmarks

Where the action is happening in this codebase.


The bulk of the file are functions which return modified versions of a windup (e.g. next, rewind), utilities (e.g. isUnplayed), or functions for creating a Windup data structure (e.g. windupFromString).

The windup data structure is also described here:

  • It has three elements, representing collections of members in three states: played, in progress, and unplayed.
  • It is a recursive data structure, i.e. a windup can be a member of any of these three parts.


This is a hook that is used internally by WindupChildren and useWindupString. It does the bulk of the work of a windup: scheduling the next update, triggering effects, returning callbacks for rewinding/skipping etc.


This hook does very little: it just turns a string into a windup and passes it along to useWindup.


A lot going on in this one: transforming the children data type into a Windup, and a rough heuristic to determine when the value of children has 'changed' (big quotation marks).