Consonant Duplicator

Duplicates every consonant letter, any letter that isn't a, e, i, o, or u, immediately after itself, useful for creating a stuttering or emphasized speech effect, stylized text, or testing layouts with doubled consonants. A free online tool from Staaarter, right in your browser.

Runs locallyUpdated 2026-07-23

Overview

Introduction

Doubling every consonant in a passage, for a stuttering or heavily emphasized speech effect, is fiddly to apply consistently across a whole passage by hand.

It runs entirely client-side, so nothing you paste is ever uploaded to a server.

What Is Consonant Duplicator?

A consonant duplicator that inserts a copy of each consonant letter, any letter that isn't a, e, i, o, or u, immediately after itself.

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 Consonant Duplicator Works

The tool checks every letter in the input, and any letter that doesn't match the vowel set has a copy of itself inserted right after it, while vowels and non-letter characters pass through untouched.

The transformation happens synchronously in JavaScript the moment you type, with no network round trip involved.

When To Use Consonant Duplicator

Use it to create a stuttering, emphasized, or stylized speech effect in dialogue, or to stress-test a UI with doubled consonant characters.

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

Often used alongside Consonant Replacer and Consonant Remover.

Features

Advantages

  • Preserves the case of every duplicated consonant automatically.
  • Leaves vowels and punctuation completely untouched.
  • Only letters are matched, so digits, punctuation, and whitespace pass through untouched and the text keeps its original structure.

Limitations

  • Treats 'y' as a consonant in every case, since it isn't part of the five-vowel set used by this tool.
  • Matches the English alphabet only, so accented and non-Latin letters are not doubled and pass through unchanged.

Examples

Duplicating consonants

Input

cat

Output

ccatt

Both 'c' and 't' are consonants and get duplicated, while the vowel 'a' is unaffected.

Best Practices & Notes

Best Practices

  • Use it sparingly on short words or phrases for the clearest stylistic effect.
  • Keep the input short, since the output grows by roughly one character per consonant and long passages quickly become unreadable.
  • Check the result where you intend to use it, because doubled consonants confuse spell-checkers and are read out literally by screen readers.

Developer Notes

The transform is `input.replace(/[a-zA-Z]/g, (char) => (/[aeiouAEIOU]/.test(char) ? char : char + char))`, so the callback checks each matched letter against the vowel set and only doubles it when it's a consonant, returning vowels unchanged.

Consonant Duplicator Use Cases

  • Creating stuttering or emphasized dialogue effects
  • Building stylized display text for a creative project
  • Stress-testing a font or layout with doubled consonant characters

Common Mistakes

  • Expecting 'y' to be treated as a vowel and skipped; it's classified as a consonant here.
  • Applying it to long passages, which can make the doubled text hard to read.

Tips

  • Pair with the Vowel Duplicator if you want every letter in the text doubled instead of just consonants.
  • Since only a-z and A-Z are matched, mixing in accented characters keeps parts of a phrase readable while the rest stutters.

References

Frequently Asked Questions