Inverse Case Converter Text
Swap every uppercase letter for lowercase and vice versa.
Inverse Case Converter is a free online tool that swap every uppercase letter for lowercase and vice versa. It runs entirely in your web browser using plain JavaScript, so files are processed on your own device and never uploaded to a server. There is no sign-up, no file size limit imposed by the site, no watermark and no paid tier.
- Price
- Free — no account, no quota, no watermark
- Category
- Text
- Where it runs
- In your browser, on your device
- Files uploaded
- None
- Technology
- plain JavaScript
- Settings
- None — it just works
- Works offline
- Yes, after the first visit
About Inverse Case Converter
Every uppercase letter becomes lowercase and every lowercase letter becomes uppercase. The transform is its own inverse for ordinary Latin text — run it twice and you are back where you started. It is genuinely useful for one thing: recovering text typed with Caps Lock stuck on, where every letter is exactly wrong.
How to use it
- Paste the text you want to run through inverse case converter.
- There is nothing to configure — the result updates as you type.
Under the hood
| Runs on | plain JavaScript — runs the whole thing |
Questions
Is it always reversible?
For plain Latin letters, yes. Characters with one-to-many case mappings such as ß do not round-trip, because ß uppercases to SS and SS lowercases to ss.
What happens to numbers and symbols?
They pass through untouched. Only characters with a defined opposite case are affected.