Replace Letters in Text

Need to swap specific letters in your text with symbols, digits, or alternate characters? The Replace Letters in Text Tool lets you define your own custom mappings – like a → @, e → 3, or i → 1 – and applies them instantly. It’s great for stylizing text, encoding patterns, or building pseudo-leetspeak effects.

Paste your input above or import a file below.
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Supported file types: .txt, .csv, .json, .html, .xml, .log, .yaml, .css
Total characters: 0
Options

How to Use:

  1. Paste or type your content into the Input Text box.
  2. (Optional) Click Choose File to upload a .txt, .csv, .json, .md, .html, or other supported file.
  3. In the Options panel, define your replacements in the Replacement Mapping box using this format: a:@ e:3 i:1 o:0 u:∪ Each pair should be separated by spaces, and each mapping uses a : (colon) between the letter and its replacement.
  4. The output updates live and appears in the Modified Output box with each keystroke or file load.
  5. Use Copy Output to copy the result, or Export to File to save it as a .txt file.
  6. Press Clear All to reset the tool and start fresh.

What Replace Letters in Text Tool can do:

This tool replaces individual letters based on your exact mappings. It works character-by-character, so only the letters you define are replaced – everything else stays the same. It supports any replacement character, including punctuation, Unicode symbols, numbers, and even emojis. You control what changes and how, and you can see the results live with a flash effect every time the output updates.

Example:

Input:

replace all vowels

Replacement Mapping:

a:@ e:3 i:1 o:0 u:∪

Output:

r3pl@c3 @ll v0∪3ls

Total characters:

18

Common Use Cases:

Perfect for generating leetspeak, encoding sensitive characters, obfuscating strings, or building stylized patterns. Writers use it for creative effects, developers use it to mask content, and educators use it to demonstrate character replacement logic. It’s flexible, fast, and fully customizable.

Useful Tools & Suggestions:

If you’re customizing how text behaves, Replace Vowels in Text helps reshape pronunciation while keeping structure intact. And if you’re going for a more complete transformation, Replace Words in Text lets you substitute entire terms useful for rewriting, censorship, or creative remixes.

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