Inverse Case Converter

Inverse case converter: swap upper and lower letters

Inverse case flips every uppercase letter to lowercase and every lowercase letter to uppercase. It is the fastest fix when a paragraph was typed with Caps Lock on—or when Shift was held on the first letter of each word.

Select only the mistaken region before converting. Running inverse case on already-correct title case will invert it into gibberish.

How to use this converter

1. Paste the block that was typed with Caps Lock or inverted shift usage.
2. Review the output—proper nouns and acronyms may still need a manual pass.
3. Follow with sentence case if the paragraph should read naturally after the swap.

Before and after examples

Only letters with upper/lowercase pairs change.

When should you use inverse case?

Use inverse case as a first pass on a uniformly wrong block: “hELLO wORLD” often becomes readable English if Caps Lock was on with occasional Shift fixes.

Do not use it as a general “fix my capitalization” tool—sentence case and title case target editorial rules; inverse case only mirrors letter height.

Inverse case vs sentence case

Sentence case rebuilds sentence boundaries and capitalizes starts of sentences. Inverse case blindly swaps case pairs. After inverse case, you may still need sentence case for a polished email or article.

What inverse case cannot recover

It cannot guess which letters were meant to be proper nouns. It does not restore deleted Shift keystrokes on individual letters. Accented characters with case pairs flip; symbols without pairs stay the same.

Common mistakes

Inverting an entire document that was only partly wrong—select the broken paragraph only.

Expecting title case output from inverse case alone.

Using inverse case on decorative Unicode text where “letters” are not standard A–Z.

Frequently asked questions

Guides and deeper reading

• Complete guide to text case
• How to fix caps lock text
• Sentence case vs title case