Swap Case: Where hELLO wORLD Comes From
Paste Hello World and you get hELLO wORLD, with punctuation, digits, and Chinese characters unchanged. It saves retyping when a heading was typed with caps lock on, or when you need messy mixed-case text for an input test.
When flipping the case is what you need
A heading typed with caps lock on gives you HELLO WORLD, and retyping it character by character is tedious. Swapping the case and then capitalising where needed is faster. Design mockups that need deliberately messy case work the same way.
Testing forms, search, or sorting often requires mixed-case input to see whether the system normalises it. A character-level flip produces a variant with exactly the same characters, which makes the comparison clean.
- Headings typed with caps lock on
- Messy-case sample text for design mockups
- Testing how forms and search handle case
How to flip without surprises
Each character is flipped: letters swap case, and everything that is not a letter — digits, punctuation, spaces, Chinese characters, kana — passes through unchanged. So Hello World becomes hELLO wORLD with commas and spaces exactly where they were.
It does not produce title case, all caps, or all lowercase; those are three different operations in a case converter, and picking the wrong one gives a completely different result. A swap is also not a normaliser: if the original was already mixed, two swaps return it unchanged, not tidied.
- Not title case, and not all caps or all lowercase
- Non-letters pass through untouched
- Two swaps restore the original, mixed case included
Where it stops, and what to use instead
It only affects cased Latin letters. Whether Greek or Cyrillic letters flip depends on the implementation, and Chinese, Japanese, and Korean are unaffected. Accented letters usually flip correctly, but combining sequences can misbehave.
There is no capitalise-first-letter, sentence case, or camelCase conversion. For those, use the matching mode in a case converter, or handle the structural part with a regex in your editor and use this tool for local touch-ups.
- Affects Latin letters only
- No title, camel, or snake case conversion
- Use a naming-convention tool for code identifiers
FAQ
Can it capitalise just the first letter of each word?
No. This flips every character: lowercase becomes uppercase and uppercase becomes lowercase, so Hello World turns into hELLO wORLD. For title case, use the title-case option in a case converter instead.
Do Chinese characters and digits change?
No. Characters without a case are emitted unchanged, so in mixed text only the Latin letters flip. Digits, punctuation, and Chinese characters stay exactly as they were.
Does swapping twice restore the original?
Usually yes. Letters flip back to their original case, but if the source was already mixed, two swaps return that same mixed state rather than a tidied one. To standardise case, use all caps, all lowercase, or title case instead.
Related tool：Swap Case