Inverse Case Converter

text

Transform text by swapping the case of each alphabetic character. Uppercase letters become lowercase and lowercase letters become uppercase, while preserving numbers, punctuation, and special characters.

Inverse Case Converter
Swap the case of each letter (uppercase ↔ lowercase)
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Inverse Case Converter - Swap Upper/Lowercase

What is an inverse case converter?

An inverse case converter flips each letter’s case: uppercase becomes lowercase and lowercase becomes uppercase. Use it to correct caps-lock errors, create stylized text, or test case sensitivity. Processing stays in your browser for privacy.

How to use the inverse case converter

  1. Enter text: Paste sentences, labels, or code snippets.
  2. Convert: Click Inverse case to swap casing.
  3. Copy or download: Copy the result or save it as a text file.

Why use this tool?

  • Fix caps-lock slips: Repair accidentally shouted text fast.
  • Testing: Check how case-sensitive systems respond to inverted inputs.
  • Styling: Add a quick twist to social captions.

Use case 1: Caps-lock recovery

Turn THIS EMAIL into this email with a single click.

Use case 2: Case sensitivity checks

Invert sample usernames or IDs to test validation rules.

Use case 3: Lighthearted posts

Swap case for a playful look in chats.

Examples

Basic example

Input: Launch Today at Noon
Output: lAUNCH tODAY AT nOON

Advanced example

Input: apiKey=SecretToken123
Output: APIkEY=sECRETtOKEN123

Common errors

Mixed acronyms

Acronyms get lowercased; adjust manually if they should stay uppercase.

Non-letter characters

Numbers and symbols stay unchanged, which is expected.

Tips and proven approaches

Related tools

Privacy and security

Conversion runs locally in your browser. No text is uploaded or stored.

Frequently Asked Questions
The inverse case converter swaps the case of each alphabetic character in your text. Uppercase letters (A-Z) become lowercase (a-z) and vice versa.
Numbers, punctuation, spaces, and special characters remain unchanged. Only alphabetic characters have their case swapped.