Case swapper
Instantly toggle the case of every letter in your text.
Case swapper
The case swapper inverts the case of every letter in your text: uppercase becomes lowercase and lowercase becomes uppercase. Paste any text and the tool transforms it instantly — "Hello World" becomes "hELLO wORLD". This is useful for testing code that handles both cases, mocking responses, toggling the appearance of variable names, or just playing with text for fun.
The transformation is straightforward: each alphabetic character flips to its opposite case while everything else stays exactly as it is. Numbers, punctuation, spaces and special characters pass through untouched. Diacritics and accented letters are preserved and handled correctly in their respective languages — é becomes É, ñ becomes Ñ, ü becomes Ü, and so on.
Everything runs in your browser without uploading anything anywhere. The live tally tracks the number of letters that were swapped and the total character count. Copy the result, download it as plain text, or send it to another tool when you are done. Use this tool whenever you need to invert the capitalization of text, whether for code testing, creating mock data, or simply experimenting with text transformations.