Letter Randomizer

Randomly shuffles the letters within each word using a Fisher-Yates shuffle, leaving word boundaries, spaces, and punctuation exactly in place. A free online tool from Staaarter, right in your browser.

Runs locallyUpdated 2026-07-23

Overview

Introduction

Randomly scrambling the letters within each word of a passage is handy for generating novelty text, puzzle content, or quick visual noise for a mockup.

This tool applies a fair, unbiased shuffle to every word in a passage at once.

What Is Letter Randomizer?

A letter randomizer that shuffles the letters within every contiguous run of letters in the text using a Fisher-Yates shuffle, leaving word order and any non-letter characters exactly in place.

It runs entirely client-side as part of this site's String Tools collection, so nothing you paste is ever uploaded to a server.

How Letter Randomizer Works

The input is tokenized into alternating runs of letters and non-letters; each letter run has its characters shuffled with a Fisher-Yates shuffle using Math.random(), while non-letter runs (spaces, digits, punctuation) pass through unchanged, and everything is rejoined in its original order.

The transformation happens synchronously in JavaScript, re-randomizing on every input change, with no network round trip involved.

When To Use Letter Randomizer

Use it to generate novelty or puzzle text, or to produce quick placeholder noise text for a mockup or design.

It's a fast way to get the effect without opening a code editor, a REPL, or writing a one-off script just to check.

Often used alongside Letter Sorter and Word Order Randomizer.

Features

Advantages

  • Uses a proper Fisher-Yates shuffle for a uniformly random letter order, not a biased approximation.
  • Preserves word boundaries and punctuation exactly, only touching the letters themselves.
  • Tokenizes into alternating letter and non-letter runs, so digits and punctuation hold their exact positions rather than drifting as the letters move.

Limitations

  • Not cryptographically secure randomness (uses Math.random()); unsuitable for anything security-sensitive.
  • Shuffles within each word without pinning the first and last letters, so words become considerably harder to read than in the familiar scrambling illusion that keeps those fixed.

Examples

Shuffling the letters of a word

Input

hello world

Output

lelho wlord

Each word's letters are randomly reordered while the space between them stays put; results vary on every run since it's random.

Best Practices & Notes

Best Practices

  • Use Letter Sorter instead if you want a deterministic, alphabetized letter order rather than a random one.
  • Run it more than once and choose a result, since a short word can easily shuffle straight back into its original order.
  • Keep the original text, because the shuffle is not reversible and nothing records the permutation that was used.

Developer Notes

Tokenization uses `input.match(/[A-Za-z]+|[^A-Za-z]+/g)`; each letter-only token is split into characters, shuffled with a standard in-place Fisher-Yates loop using `Math.random()`, and rejoined, while non-letter tokens pass through unmodified.

Letter Randomizer Use Cases

  • Generating novelty or puzzle text
  • Producing placeholder noise text for a design mockup
  • Creating a randomized variant of a passage for fun

Common Mistakes

  • Expecting the same input to always produce the same output; the shuffle is random and changes each time.
  • Relying on it to obscure sensitive text; the letters and their counts are unchanged, so the content is trivially recoverable.

Tips

  • Pair with Word Order Randomizer for an even more scrambled version that also reorders whole words.
  • Words of one or two letters frequently come out unchanged, which is expected rather than a sign the shuffle failed.

References

Frequently Asked Questions