Case Converter — UPPERCASE, lowercase & Title Case
Instantly convert text between UPPERCASE, lowercase, Title Case, Sentence case, Capitalize Each Word, iNVERT cASE, kebab-case and snake_case. Built for copywriters, marketers and developers who work in Thai and English — Thai characters have no case, so they always pass through untouched. Free, no sign-up, and everything runs in your browser.
Thai characters have no upper or lower case, so they always pass through unchanged.
Choose a case
Thai characters are not affected — Thai has no upper or lower case.
For a real SEO-friendly slug that splits Thai words correctly, use the URL Slug Generator
Your converted text will appear here
Type some text, then pick a case above.
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How to use
- Type or paste your text into the box.
- Click a case button — UPPERCASE, lowercase, Title Case, Sentence case and more.
- The converted text appears instantly in the result box with live character, word and line counts.
- Copy the result, or click "Use as input" to keep converting the same text.
- Made a mistake? Click "Undo" to restore the previous text.
Features
- Eight one-click conversions: UPPER, lower, Title, Sentence, Capitalize Each Word, iNVERT, kebab and snake
- Smart Title Case that keeps small words like "a", "of" and "the" lowercase
- Correct handling of names and compounds such as O'Brien and e-commerce
- Thai-safe — Thai letters have no case and are never altered
- One-level undo and a "Use as input" swap for chaining conversions
- 100% in-browser — your text is never uploaded
Frequently asked questions
Does this case converter change my Thai text?
No. Thai script has no uppercase or lowercase letters, so every Thai character passes through exactly as you typed it. Only Latin letters in mixed Thai-English text are converted.
How does Title Case decide which words to capitalize?
It capitalizes the first letter of each word but keeps common small words — a, an, the, of, to, and, or, in and similar — lowercase, unless they are the first or last word. This matches standard English headline style.
What is the difference between Title Case and Capitalize Each Word?
Title Case follows headline rules and leaves small words like "of" and "the" lowercase in the middle of a phrase. Capitalize Each Word capitalizes the first letter of every word with no exceptions.
What do kebab-case and snake_case do?
They lowercase the text and replace spaces with a hyphen (kebab-case) or underscore (snake_case), dropping punctuation. For a true SEO-friendly URL slug that also splits Thai words, use our URL Slug Generator instead.
Is my text sent to a server?
No. All conversions happen in your browser with JavaScript. Your text never leaves your device.